• Title/Summary/Keyword: System Capacity

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High-Temperature Cesium (Cs) Retention Ability of Cs-Exchanged Birnessite (세슘(Cs)으로 이온 교환된 버네사이트의 고온에서의 Cs 고정 능력)

  • Yeongkyoo Kim
    • Korean Journal of Mineralogy and Petrology
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    • v.36 no.4
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    • pp.313-321
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    • 2023
  • Numerous studies have investigated the adsorptive sequestration of radioactive cesium in the natural environment. Among these studies, adsorption onto minerals and high-temperature treatment stand out as highly effective, as demonstrated by the use of zeolite. In this study, cesium was ion-exchanged with birnessite and subsequently underwent high-temperature treatment up to 1100℃ to investigate both mineral phase transformation and the leaching characteristics of cesium. Birnessite has a layered structure consisting of MnO6 octahedrons that share edges, demonstrating excellent cation adsorption capacity. The high-temperature treatment of cesium-ion-exchanged birnessite resulted in changes in the mineral phase, progressing from cryptomelane, bixbyite, birnessite to hausmannite as the temperature increased. This differs from the phase transformation observed in the tunneled manganese oxide mineral todorokite ion-exchanged with cesium, which shows phase transformation only to birnessite and hausmannite. The leaching of cesium from cesium-ion-exchanged birnessite was estimated by varying the reaction time using both distilled water and a 1 M NaCl solution. The leaching quantity changed according to the treatment temperature, reaction time, and type of reaction solution. Specifically, the cesium leaching was higher in the sample reacted with 1 M NaCl compared to the sample with distilled water and also increased with longer reaction time. For the samples reacted with distilled water, the cesium leaching initially increased and then decreased, while in the NaCl solution, the leaching decreased, increased again, and finally nearly stopped like the sample in the distilled water for the sample treated at 1100℃. These changes in leaching are closely associated with the mineral phases formed at different temperatures. The phase transformation to cryptomelane and birnessite enhanced cesium leaching, whereas bixbyite and hausmannite hindered leaching. Notably, hausmannite, the most stable phase occurring at the highest temperature, demonstrated the greatest ability to inhibit cesium leaching. This results strongly suggest that high-temperature treatment of cesium-ion-exchanged birnessite effectively immobilizes and sequesters cesium.

The Structural Relationship between Entrepreneurial Competency, Entrepreneurial Opportunity Recognition on and Entrepreneurial Intentions of Middle-aged Eldery Office Workers (중·장년 직장인의 창업역량과 창업기회인식 및 창업의지의 구조적 관계)

  • Choi, In Woo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.5
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    • pp.169-185
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    • 2022
  • This study analyzed the effect of entrepreneurial competency on entrepreneurial intentions by using the entrepreneurial opportunity recognition as a mediator for middle and middle-aged office workers. The sub-variables of entrepreneurial competency are classified into management competency, technology competency, business competency and funding competency. 222 copies of questionnaires collected from middle-aged and elderly office workers residing across the country centered on the metropolitan area were used for empirical analysis. Based on a simple mediating model with singular mediator using SPSS v22.0 and PROCESS macro v4.0. was analyzed. As a result of the analysis, first, among entrepreneurial competencies, business competency and funding capacity were found to have a positive (+) significant effect on the entrepreneurial intentions, but management and technical competency did not have a significant effect. The higher the business competency and funding competency. Second, it was found that all of the sub-variables of entrepreneurial competency had a significant effect in the positive (+) direction on the recognition of entrepreneurial opportunities. It was confirmed that management competency has the greatest influence on the entrepreneurial opportunity recognition and technology competence has the smallest effect. Third, it was found that the entrepreneurial opportunity recognition had a significant effect on entrepreneurial intentions. The discovery of an opportunity recognizing opportunities for start-up is a prerequisite for entrepreneur. Fourth, it was found that the entrepreneurial opportunity recognition mediates between the management competency, technological competency, business competency, funding competency, and entrepreneurial intention. It suggests that opportunity discovery by recognizing opportunities for entrepreneurship is a prerequisite for start-up. As implications of this study, it suggests that in order to inspire middle-aged and elderly office workers to start their own business, it is necessary to have indirect experience with education and to establish and promote a government support system for financing.. Second, It suggests that education on leadership and organizational management is particularly necessary to strengthen the opportunity recognition. Third, it suggests that the discovery of opportunities to recognize opportunities for start-up is a prerequisite for entrepreneur. Therefore, it is necessary to prepare a manual and conduct training on opportunity search, recognition, evaluation, and utilization according to the stage of opportunity development. Fourth, it suggests that in order to strengthen the intention to start a business, ALso, it is necessary to manage both the entrepreneurial competency and entrepreneurial opportunities recognition at the same time. By presenting the practical directions that can be given differentially, we intend to contribute to the provision of practical directions and policy establishment for the promotion of entrepreneurial activities of office workers who can give vitality to the ecosystem.

Analysis of Perceptions of Student Start-up Policies in Science and Technology Colleges: Focusing on the KAIST case (과기특성화대학 학생창업정책에 대한 인식분석: KAIST 사례를 중심으로)

  • Tae-Uk Ahn;Chun-Ryol Ryu;Minjung Baek
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.19 no.2
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    • pp.197-214
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    • 2024
  • This study aimed to investigate students' perceptions at science and technology specialized universities towards entrepreneurship support policies and to derive policy improvement measures by applying a bottom-up approach to reflect the requirements of the policy beneficiaries, i.e., the students. Specifically, the research explored effective execution strategies for student entrepreneurship support policies through a survey and analysis of KAIST students. The findings revealed that KAIST students recognize the urgent need for improvement in sharing policy objectives with the student entrepreneurship field, reflecting the opinions of the campus entrepreneurship scene in policy formulation, and constructing an entrepreneurship-friendly academic system for nurturing student entrepreneurs. Additionally, there was a highlighted need for enhancement in the capacity of implementing agencies, as well as in marketing and market development capabilities, and organizational management and practical skills as entrepreneurs within the educational curriculum. Consequently, this study proposes the following improvement measures: First, it calls for enhanced transparency and accessibility of entrepreneurship support policies, ensuring students clearly understand policy objectives and can easily access information. Second, it advocates for student-centered policy development, where students' opinions are actively incorporated to devise customized policies that consider their needs and the actual entrepreneurship environment. Third, there is a demand for improving entrepreneurship-friendly academic systems, encouraging more active participation in entrepreneurship activities by adopting or refining academic policies that recognize entrepreneurship activities as credits or expand entrepreneurship-related courses. Based on these results, it is expected that this research will provide valuable foundational data to actively support student entrepreneurship in science and technology specialized universities, foster an entrepreneurial spirit, and contribute to the creation of an innovation-driven entrepreneurship ecosystem that contributes to technological innovation and social value creation.

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Cardio-pulmonary Adaptation to Physical Training (운동훈련(運動訓練)에 대(對)한 심폐기능(心肺機能)의 적응(適應)에 관(關)한 연구(硏究))

  • Cho, Kang-Ha
    • The Korean Journal of Physiology
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    • v.1 no.1
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    • pp.103-120
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    • 1967
  • As pointed out by many previous investigators, the cardio-pulmonary system of well trained athletes is so adapted that they can perform a given physical exercise more efficiently as compared to non-trained persons. However, the time course of the development of these cardio-pulmonary adaptations has not been extensively studied in the past. Although the development of these training effects is undoubtedly related to the magnitude of an exercise load which is repeatedly given, it would be practical if one could maintain a good physical fitness with a minimal daily exercise. Hence, the present investigation was undertaken to study the time course of the development of cardio-pulmonary adaptations while a group of non-athletes was subjected to a daily 6 to 10 minutes running exercise for a period of 4 weeks. Six healthy male medical students (22 to 24 years old) were randomly selected as experimental subjects, and were equally divided into two groups (A and B). Both groups were subjected to the same daily running exercise (approximately 1,000 kg-m). 6 days a week for 4 weeks, but the rate of exercise was such that the group A ran on treadmill with 8.6% grade for 10 min daily at a speed of 127 m/min while the group B ran for 6 min at a speed of 200 m/min. In order to assess the effects of these physical trainings on the cardio-pulmonary system, the minute volume, the $O_2$ consumption, the $CO_2$ output and the heart rate were determined weekly while the subject was engaged in a given running exercise on treadmill (8.6% grade and 127 m/min) for a period of 5 min. In addition, the arterial blood pressure, the cardiac output, the acid-base state of arterial blood and the gas composition of arterial blood were also determined every other week in 4 subjects (2 from each group) while they were engaged in exercise on a bicycle ergometer at a rate of approximately 900 kg m/min until exhaustion. The maximal work capacity was also determined by asking the subject to engage in exercise on treadmill and ergometer until exhaustion. For the measurement of minute volume, the expired gas was collected in a Douglas bag. The $O_2$ consumption and the $CO_2$ output were subsequently computed by analysing the expired gas with a Scholander micro gas analyzer. The heart rate was calculated from the R-R interval of ECG tracings recorded by an Offner RS Dynograph. A 19 gauge Cournand needle was inserted into a brachial artery, through which arterial blood samples were taken. A Statham $P_{23}AA$ pressure transducer and a PR-7 Research Recorder were used for recording instantaneous arterial pressure. The cardiac output was measured by indicator (Cardiogreen) dilution method. The results may be summarized as follows: (1) The maximal running time on treadmill increased linearly during the 4 week training period at the end of which it increased by 2.8 to 4.6 times. In general, an increase in the maximal running time was greater when the speed was fixed at a level at which the subject was trained. The mammal exercise time on bicycle ergometer also increased linearly during the training period. (2) In carrying out a given running exercise on treadmill (8.6%grade, 127 m/min), the following changes in cardio·pulmonary functions were observed during the training period: (a) The minute volume as well as the $O_2$ consumption during steady state exercise tended to decrease progressively and showed significant reductions after 3 weeks of training. (b) The $CO_2$ production during steady state exercise showed a significant reduction within 1 week of training. (c) The heart rate during steady state exercise tended to decrease progressively and showed a significant reduction after 2 weeks of training. The reduction of heart rate following a given exercise tended to become faster by training and showed a significant change after 3 weeks. Although the resting heart rate also tended to decrease by training, no significant change was observed. (3) In rallying out a given exercise (900 kg-m/min) on a bicycle ergometer, the following change in cardio-vascular functions were observed during the training period: (3) The systolic blood pressure during steady state exercise was not affected while the diastolic blood Pressure was significantly lowered after 4 weeks of training. The resting diastolic pressure was also significantly lowered by the end of 4 weeks. (b) The cardiac output and the stroke volume during steady state exercise increased maximally within 2 weeks of training. However, the resting cardiac output was not altered while the resting stroke volume tended to increase somewhat by training. (c) The total peripheral resistance during steady state exercise was greatly lowered within 2 weeks of training. The mean circulation time during exorcise was also considerably shortened while the left heart work output during exercise increased significantly within 2 weeks. However, these functions_at rest were not altered by training. (d) Although both pH, $P_{co2}\;and\;(HCO_3-)$ of arterial plasma decreased during exercise, the magnitude of reductions became less by training. On the other hand, the $O_2$ content of arterial blood decreased during exercise before training while it tended to increase slightly after training. There was no significant alteration in these values at rest. These results indicate that cardio-pulmonary adaptations to physical training can be acquired by subjecting non-athletes to brief daily exercise routine for certain period of time. Although the time of appearance of various adaptive phenomena is not identical, it may be stated that one has to engage in daily exercise routine for at least 2 weeks for the development of significant adaptive changes.

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The Effects of the Computer Aided Innovation Capabilities on the R&D Capabilities: Focusing on the SMEs of Korea (Computer Aided Innovation 역량이 연구개발역량에 미치는 효과: 국내 중소기업을 대상으로)

  • Shim, Jae Eok;Byeon, Moo Jang;Moon, Hyo Gon;Oh, Jay In
    • Asia pacific journal of information systems
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    • v.23 no.3
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    • pp.25-53
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    • 2013
  • This study analyzes the effect of Computer Aided Innovation (CAI) to improve R&D Capabilities empirically. Survey was distributed by e-mail and Google Docs, targeting CTO of 235 SMEs. 142 surveys were returned back (rate of return 60.4%) from companies. Survey results from 119 companies (83.8%) which are effective samples except no-response, insincere response, estimated value, etc. were used for statistics analysis. Companies with less than 50billion KRW sales of entire researched companies occupy 76.5% in terms of sample traits. Companies with less than 300 employees occupy 83.2%. In terms of the type of company business Partners (called 'partners with big companies' hereunder) who work with big companies for business occupy 68.1%. SMEs based on their own business (called 'independent small companies') appear to occupy 31.9%. The present status of holding IT system according to traits of company business was classified into partners with big companies versus independent SMEs. The present status of ERP is 18.5% to 34.5%. QMS is 11.8% to 9.2%. And PLM (Product Life-cycle Management) is 6.7% to 2.5%. The holding of 3D CAD is 47.1% to 21%. IT system-holding and its application of independent SMEs seemed very vulnerable, compared with partner companies of big companies. This study is comprised of IT infra and IT Utilization as CAI capacity factors which are independent variables. factors of R&D capabilities which are independent variables are organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability. The highest average value of variables was 4.24 in organization capability 2. The lowest average value was 3.01 in IT infra which makes users access to data and information in other areas and use them with ease when required during new product development. It seems that the inferior environment of IT infra of general SMEs is reflected in CAI itself. In order to review the validity used to measure variables, Factors have been analyzed. 7 factors which have over 1.0 pure value of their dependent and independent variables were extracted. These factors appear to explain 71.167% in total of total variances. From the result of factor analysis about measurable variables in this study, reliability of each item was checked by Cronbach's Alpha coefficient. All measurable factors at least over 0.611 seemed to acquire reliability. Next, correlation has been done to explain certain phenomenon by correlation analysis between variables. As R&D capabilities factors which are arranged as dependent variables, organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability turned out that they acquire significant correlation at 99% reliability level in all variables of IT infra and IT Utilization which are independent variables. In addition, correlation coefficient between each factor is less than 0.8, which proves that the validity of this study judgement has been acquired. The pair with the highest coefficient had 0.628 for IT utilization and technology-accumulating capability. Regression model which can estimate independent variables was used in this study under the hypothesis that there is linear relation between independent variables and dependent variables so as to identify CAI capability's impact factors on R&D. The total explanations of IT infra among CAI capability for independent variables such as organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability are 10.3%, 7%, 11.9%, 30.9%, and 10.5% respectively. IT Utilization exposes comprehensively low explanatory capability with 12.4%, 5.9%, 11.1%, 38.9%, and 13.4% for organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability respectively. However, both factors of independent variables expose very high explanatory capability relatively for technology-accumulating capability among independent variable. Regression formula which is comprised of independent variables and dependent variables are all significant (P<0.005). The suitability of regression model seems high. When the results of test for dependent variables and independent variables are estimated, the hypothesis of 10 different factors appeared all significant in regression analysis model coefficient (P<0.01) which is estimated to affect in the hypothesis. As a result of liner regression analysis between two independent variables drawn by influence factor analysis for R&D capability and R&D capability. IT infra and IT Utilization which are CAI capability factors has positive correlation to organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability with inside and outside which are dependent variables, R&D capability factors. It was identified as a significant factor which affects R&D capability. However, considering adjustable variables, a big gap is found, compared to entire company. First of all, in case of partner companies with big companies, in IT infra as CAI capability, organization capability, process capability, human resources capability, and technology capability out of R&D capacities seems to have positive correlation. However, collaboration capability appeared insignificance. IT utilization which is a CAI capability factor seemed to have positive relation to organization capability, process capability, human resources capability, and internal/external collaboration capability just as those of entire companies. Next, by analyzing independent types of SMEs as an adjustable variable, very different results were found from those of entire companies or partner companies with big companies. First of all, all factors in IT infra except technology-accumulating capability were rejected. IT utilization was rejected except technology-accumulating capability and collaboration capability. Comprehending the above adjustable variables, the following results were drawn in this study. First, in case of big companies or partner companies with big companies, IT infra and IT utilization affect improving R&D Capabilities positively. It was because most of big companies encourage innovation by using IT utilization and IT infra building over certain level to their partner companies. Second, in all companies, IT infra and IT utilization as CAI capability affect improving technology-accumulating capability positively at least as R&D capability factor. The most of factor explanation is low at around 10%. However, technology-accumulating capability is rather high around 25.6% to 38.4%. It was found that CAI capability contributes to technology-accumulating capability highly. Companies shouldn't consider IT infra and IT utilization as a simple product developing tool in R&D section. However, they have to consider to use them as a management innovating strategy tool which proceeds entire-company management innovation centered in new product development. Not only the improvement of technology-accumulating capability in department of R&D. Centered in new product development, it has to be used as original management innovative strategy which proceeds entire company management innovation. It suggests that it can be a method to improve technology-accumulating capability in R&D section and Dynamic capability to acquire sustainable competitive advantage.

Study on Medical Records In ${\ulcorner}$the Historical Records of the Three Kingdoms${\lrcorner}$ ("삼국사기(三國史記)"에 기록된 의약내용(醫藥內容) 분석)

  • Shin, Soon-Shik;Choi, Hwan-Soo
    • Journal of The Association for Neo Medicine
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    • v.2 no.1
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    • pp.35-54
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    • 1997
  • We tried to observe the features of ancient medical practice by analysing the records related to medicine in the book, ${\ulcorner}$the Historical Records of the Three Kingdom${\lrcorner}$ of which content includes the features of medicine in mythology, plague, delivery of twins, drugs, medical system, shamanism, constitutional medicine, psychiatry, forensic medicine, deformity, a spa, medical phrase, health and welfare work, religion, death. physiological anatomy, Taoist medicine, acupuncture, the occult af of transformation and etc. Our initial concern was about where to draw line as of medical field and we defined medicine in more broad meaning. The book ${\ulcorner}$the Historical Records of the Three Kingdoms${\lrcorner}$ describes the world of mythology by way of medicine which is not clearly a conventional one. There appears records of birth of multiple offsprings 7 times in which cases are of triplets or more. Delivering multiple offsprings were rare phenomenon though such fertility was highly admired. This shows one aspect of ancient country having more population meant more power of the nation. Of those medical records conveyed in that book includes stories of childbirth such as giving birth to a son after praying, giving birth to Kim Yoo-shin after 20 months after mother's dream of conception, and a song longing for getting a laudable child. Plagues were prevalent throughout winter to spring season and one can observe various symptoms of plagues in the record. Of these epidemic diseases, cold type might have been more common than the heat one. Appearance of epidemic diseases frequently coincided with that of natural disasters that this suggests a linkage between plague and underlying doctrine on five elements' motion and six kinds of natural factors. There exists only a few names of diseases such as epidemic disease, wind disease, and syndrome characterized by dyspnea. Otherwise there appeared only afflictions that were not specified therefore it remains cluless to keep track of certain diseases of prevalence. Since this ${\ulcorner}$Historical Records of the Three Kingdoms'${\lrcorner}$ wasn't any sort of medical book, words and terms used were not technical kind and most were the ones used generally among lay people. Therefore any mechanisms of the diseases were hardly mentioned. Some of medicinal substances such as Calculus Bovis, Radix Ginseng, Gaboderma Luciderm, magnetitum were also in use in those days. 53 kinds of dietary supplies appears in the records and some of these might have been used as medicinal purpose. Records concerning dicipline of one's body includes activities such as hunting, archery, horseback riding etc. In Shilla dynasty there were positions such as professor of medicine, Naekongbong(內供奉), Kongbong's doctor(供奉醫師), Kongbong's diviner(供奉卜師). As an educational facility, medical school was built at the first year of King Hyoso's reign and it's curricula included various subjects as ${\ulcorner}$Shin Nong's Herbal classic${\lrcorner}$, ${\ulcorner}$Kabeul classic of acupuncture and moxbustion${\lrcorner}$, ${\ulcorner}$The Plain Questions of the Yellow Emperor's Classic of Internal Medicine${\lrcorner}$, ${\ulcorner}$Classic of Acupuncturer${\lrcorner}$, ${\ulcorner}$The Pulse Classic${\lrcorner}$, ${\ulcorner}$Classic of Channels and Acupuncture Points${\lrcorner}$ and ${\ulcorner}$Difficult Classic${\lrcorner}$. There were 2 medical professors who were in charge of education. To establish pharmacopoeia, 2 Shaji(舍知), 6 Sha(史), 2 Jongshaji(從舍知) were appointed. In Baekje dynasty, Department of Herb was maintained. Doing praying for the sake of health, doing phrenology also can be extended to medical arena. Those who survived over 100 years of age appear 3 times in the record, while 98 appears once. The earliest psychiatrist Nokjin differentiated symptoms to apply either therapies using acupuncture and drug or psychotherapy. There appears a case of rape, a case of burying alive with the dead, 8 cases of suicide that can characterize a prototype of forensic medicine. Deformity-related records include phrases as follow: 'there seems protrudent bone behind the head', 'a body which has two heads, two trunks, four arms.', 'a body equipped with two heads' In those times spa can be said to be used as a place for he리ing, convalescence, and relaxation seeing the records describing a person pretended illness and went to spa to enjoy with his friends. Priest doctors and millitary surgeons were in charge of the medical sevice in the period of the Three Kingdoms by the record written by Mookhoja(墨胡子) and Hoonkyeom(訓謙). Poor diet and regimen makes people more vulnerable to diseases. So there existed charity services for those poor people who couldn't live with one's own capacity such as single parents, orphans, the aged people no one to take care and those who are ill. The cause of affliction was frequently coined with human relation. There appeared the phenomenon of releasing prisoners and allowing people to become priests at the time of king's suffering. Besides, as a healing procedure, sutra-chanting was peformed. There appears 10 cases of death related records which varies from death by drowning, or by freezing, death from animals, death from war, death from wightloss and killing oneself at the moment of spouse's death and etc. There also exist certain records which suggest the knowledge of physiology and anatomy in those times. Since the taoist books such as ${\ulcorner}$Book of the Way and Its Power(老子道德經)${\lrcorner}$ were introduced in the period of Three Kingdoms, it can be considered that medicine was also influenced by taoism. Records of higher level of acupuncture, records which links the medicine and occult art of transformation existed. Although limited, we could figure out the medical state of ancient society.

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A Study on Rationalization of National Forest Management in Korea (국유림경영(國有林經營)의 합리화(合理化)에 관(關)한 연구(硏究))

  • Choi, Kyu-Ryun
    • Journal of Korean Society of Forest Science
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    • v.20 no.1
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    • pp.1-44
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    • 1973
  • Needless to say, the management of national forest in all countries is very important in view of the national mission and management purposes. Korean national forest is also in particular significant in promoting national economy for the continuous increasing of the demand for wood, conservation of the land and social welfare. But there's no denying the fact that the leading aim of the Korean forest policy has been based upon the conservation of forest resources and recovery of land conservation function instead of improvement of the forest productive capacity. Therefore, the management of national forest should be aimed as an industry in the chain of the Korean national economy. And the increment of the forest productive capacity based on rationalized forest management is also urgently needed. Not only the increment of the timber production but also the establishment of the good forest in quality and quantity are to bring naturally many functions of conservation and other public benefits. In 1908 Korean national forest was historically established for the first time as a result of the notification for ownership, and was divided into two kinds in 1911-1924, such as indisposable national forest for land conservation, forest management, scientific research and public welfare, and the other national forest to be disposed. Indisposable forest is mostly under the jurisdiction of national forest stations (Chungbu, Tongbu, Nambu), and the tother national forests are under custody of respective cities and provinces, and under custody of the other government authorities. As of the end of 1971, national forest land is 19.5% (1,297,708 ha) of the total forest land area, but growing stock is 50.1% ($35,406,079m^3$) of the total forest growing stock, and timber production of national forest is 23.6% ($205,959m^3$) of the year production of total timber in Korea. Accordingly, it is the important fact that national forest occupies the major part of Korean forestry. The author positively affirms that success or failure of the management of national forest controls rise or fall of forestry in Korea. All functions of forest are very important, but among others the function of timber production is most important especially in Korea, that unavoidably imports a large quantity of foreign wood every year (in 1971 import of foreign wood-$3,756,000m^3$, 160,995,000 dollars). So, Korea urgently needs the improvement of forest productive capacity in national forest. But it is difficult that wood production meets the rapid increase of demand for wood to the development of economy, because production term of forestry is long, so national forest management should be rationalized by the effective investment and development of forestry techniques in the long view. Although Korean national forest business has many difficulties in the budget, techniques and the lack of labour due to outflow of rural village labour by development of national economy, and the increase of labour wages and administrative expenses etc. the development of national forest depends on adoption of the suitable forest techniques and management adapted for social and economical development. In this view point the writer has investigated and analyzed the status of the management of national forest in Korea to examine the irrational problems and suggest an improvement plan. The national forestry statistics cited in this study is based on the basic statistics and the statistics of the forest business as of the end of 1971 published by Office of Forestry, Republic of Korea, and the other depended on the data presented by the national forest stations. The writer wants to propose as follows (seemed to be helpful in improvement of Korean national forest management). 1) In the organization of national forest management, more national forest stations should be established to manage intensively, and the staff of working plan officials should be strengthened because of the importance of working plan. 2) By increasing the staff of protection officials, forest area assigned for each protection official should be decreased to 1,000-2,000 ha. 3) The frequent personnel changes of supervisor of national forest station(the responsible person on-the-spot) obstructs to accomplish the consistent management plan. 4) In the working plan drafting for national forest, basic investigations should be carefully practiced with sufficient expenditure and staff not to draft unreal working plan. 5) The area of working-unit should be decreased to less than 2,000 ha on the average for intensive management and the principle of a working-unit in a forest station should be realized as soon as possible. 6) Reforestation on open land should be completed in a short time with a debt of the special fund(a long term loan), and the land on which growing hardwood stands should be changed with conifers to increase productivity per unit area, and at the same time techical utilization method of hardwood should be developed. 7) Expenses of reforestation should be saved by mechanization and use of chemicals for reforestation and tree nursery operation providing against the lack of labour in future. 8) In forest protection, forest fire damage is enormous in comparison with foreign countries, accordingly prevention system and equipment should be improved, and also the minimum necessary budget should be counted up for establishment and manintenance of fire-lines. 9) Manufacture production should be enlarged to systematize protection, processing and circulation of forest business, and, by doing this, mich benefit is naturally given for rural people. 10) Establishment and arrangement of forest road networks and erosion control work are indispensable for the future development of national forest itself and local development. Therefore, these works should be promoted by the responsibility of general accounting instead of special accounting. 11) Mechanization of forest works should be realized for exploiting hinterlands to meet the demand for timber increased and for solving lack of labour, consequently it should promote import of forest machines, home production, training for operaters and careful adminitration. 12) Situation of labour in future will grow worse. Therefore, the countermeasure to maintain forest labourers and pay attention to public welfare facilities and works should be considered. 13) Although the condition of income and expenditure grows worse because of economical change, the regular expenditure should be fixed. So part of the surplus fund, as of the end of 1971, should be established for the fund, and used for enlarging reforestation and forest road networks(preceding investment in national forest).

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Field Studios of In-situ Aerobic Cometabolism of Chlorinated Aliphatic Hydrocarbons

  • Semprini, Lewts
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.04a
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    • pp.3-4
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    • 2004
  • Results will be presented from two field studies that evaluated the in-situ treatment of chlorinated aliphatic hydrocarbons (CAHs) using aerobic cometabolism. In the first study, a cometabolic air sparging (CAS) demonstration was conducted at McClellan Air Force Base (AFB), California, to treat chlorinated aliphatic hydrocarbons (CAHs) in groundwater using propane as the cometabolic substrate. A propane-biostimulated zone was sparged with a propane/air mixture and a control zone was sparged with air alone. Propane-utilizers were effectively stimulated in the saturated zone with repeated intermediate sparging of propane and air. Propane delivery, however, was not uniform, with propane mainly observed in down-gradient observation wells. Trichloroethene (TCE), cis-1, 2-dichloroethene (c-DCE), and dissolved oxygen (DO) concentration levels decreased in proportion with propane usage, with c-DCE decreasing more rapidly than TCE. The more rapid removal of c-DCE indicated biotransformation and not just physical removal by stripping. Propane utilization rates and rates of CAH removal slowed after three to four months of repeated propane additions, which coincided with tile depletion of nitrogen (as nitrate). Ammonia was then added to the propane/air mixture as a nitrogen source. After a six-month period between propane additions, rapid propane-utilization was observed. Nitrate was present due to groundwater flow into the treatment zone and/or by the oxidation of tile previously injected ammonia. In the propane-stimulated zone, c-DCE concentrations decreased below tile detection limit (1 $\mu$g/L), and TCE concentrations ranged from less than 5 $\mu$g/L to 30 $\mu$g/L, representing removals of 90 to 97%. In the air sparged control zone, TCE was removed at only two monitoring locations nearest the sparge-well, to concentrations of 15 $\mu$g/L and 60 $\mu$g/L. The responses indicate that stripping as well as biological treatment were responsible for the removal of contaminants in the biostimulated zone, with biostimulation enhancing removals to lower contaminant levels. As part of that study bacterial population shifts that occurred in the groundwater during CAS and air sparging control were evaluated by length heterogeneity polymerase chain reaction (LH-PCR) fragment analysis. The results showed that an organism(5) that had a fragment size of 385 base pairs (385 bp) was positively correlated with propane removal rates. The 385 bp fragment consisted of up to 83% of the total fragments in the analysis when propane removal rates peaked. A 16S rRNA clone library made from the bacteria sampled in propane sparged groundwater included clones of a TM7 division bacterium that had a 385bp LH-PCR fragment; no other bacterial species with this fragment size were detected. Both propane removal rates and the 385bp LH-PCR fragment decreased as nitrate levels in the groundwater decreased. In the second study the potential for bioaugmentation of a butane culture was evaluated in a series of field tests conducted at the Moffett Field Air Station in California. A butane-utilizing mixed culture that was effective in transforming 1, 1-dichloroethene (1, 1-DCE), 1, 1, 1-trichloroethane (1, 1, 1-TCA), and 1, 1-dichloroethane (1, 1-DCA) was added to the saturated zone at the test site. This mixture of contaminants was evaluated since they are often present as together as the result of 1, 1, 1-TCA contamination and the abiotic and biotic transformation of 1, 1, 1-TCA to 1, 1-DCE and 1, 1-DCA. Model simulations were performed prior to the initiation of the field study. The simulations were performed with a transport code that included processes for in-situ cometabolism, including microbial growth and decay, substrate and oxygen utilization, and the cometabolism of dual contaminants (1, 1-DCE and 1, 1, 1-TCA). Based on the results of detailed kinetic studies with the culture, cometabolic transformation kinetics were incorporated that butane mixed-inhibition on 1, 1-DCE and 1, 1, 1-TCA transformation, and competitive inhibition of 1, 1-DCE and 1, 1, 1-TCA on butane utilization. A transformation capacity term was also included in the model formation that results in cell loss due to contaminant transformation. Parameters for the model simulations were determined independently in kinetic studies with the butane-utilizing culture and through batch microcosm tests with groundwater and aquifer solids from the field test zone with the butane-utilizing culture added. In microcosm tests, the model simulated well the repetitive utilization of butane and cometabolism of 1.1, 1-TCA and 1, 1-DCE, as well as the transformation of 1, 1-DCE as it was repeatedly transformed at increased aqueous concentrations. Model simulations were then performed under the transport conditions of the field test to explore the effects of the bioaugmentation dose and the response of the system to tile biostimulation with alternating pulses of dissolved butane and oxygen in the presence of 1, 1-DCE (50 $\mu$g/L) and 1, 1, 1-TCA (250 $\mu$g/L). A uniform aquifer bioaugmentation dose of 0.5 mg/L of cells resulted in complete utilization of the butane 2-meters downgradient of the injection well within 200-hrs of bioaugmentation and butane addition. 1, 1-DCE was much more rapidly transformed than 1, 1, 1-TCA, and efficient 1, 1, 1-TCA removal occurred only after 1, 1-DCE and butane were decreased in concentration. The simulations demonstrated the strong inhibition of both 1, 1-DCE and butane on 1, 1, 1-TCA transformation, and the more rapid 1, 1-DCE transformation kinetics. Results of tile field demonstration indicated that bioaugmentation was successfully implemented; however it was difficult to maintain effective treatment for long periods of time (50 days or more). The demonstration showed that the bioaugmented experimental leg effectively transformed 1, 1-DCE and 1, 1-DCA, and was somewhat effective in transforming 1, 1, 1-TCA. The indigenous experimental leg treated in the same way as the bioaugmented leg was much less effective in treating the contaminant mixture. The best operating performance was achieved in the bioaugmented leg with about over 90%, 80%, 60 % removal for 1, 1-DCE, 1, 1-DCA, and 1, 1, 1-TCA, respectively. Molecular methods were used to track and enumerate the bioaugmented culture in the test zone. Real Time PCR analysis was used to on enumerate the bioaugmented culture. The results show higher numbers of the bioaugmented microorganisms were present in the treatment zone groundwater when the contaminants were being effective transformed. A decrease in these numbers was associated with a reduction in treatment performance. The results of the field tests indicated that although bioaugmentation can be successfully implemented, competition for the growth substrate (butane) by the indigenous microorganisms likely lead to the decrease in long-term performance.

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Antimicrobial, Antioxidant and Cellular Protective Effects against Oxidative Stress of Anemarrhena asphodeloides Bunge Extract and Fraction (지모 뿌리 추출물과 분획물의 항균활성과 항산화 활성 및 세포보호 연구)

  • Lee, Yun Ju;Song, Ba Reum;Lee, Sang Lae;Shin, Hyuk Soo;Park, Soo Nam
    • Microbiology and Biotechnology Letters
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    • v.46 no.4
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    • pp.360-371
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    • 2018
  • Extracts and fractions of Anemarrhena asphodeloides Bunge were prepared and their physiological activities and components were analyzed. Antimicrobial activities of the ethyl acetate and aglycone fractions were $78{\mu}g/ml$ and $31{\mu}g/ml$, respectively, for Staphylococcus aureus and $156{\mu}g/ml$ and $125{\mu}g/ml$, respectively, for Pseudomonas aeruginosa. 1,1-Diphenyl-2-picrylhydrazyl free radical scavenging activities ($FSC_{50}$) of 50% ethanol extract, ethyl acetate fraction, and aglycone fraction of A. asphodeloides extracts were $146.2{\mu}g/ml$, $23.19{\mu}g/ml$, and $71.06{\mu}g/ml$, respectively. The total antioxidant capacity ($OSC_{50}$) in an $Fe^{3+}$-EDTA/hydrogen peroxide ($H_2O_2$) system were $17.5{\mu}g/ml$, $1.5{\mu}g/ml$, and $1.4{\mu}g/ml$, respectively. The cytoprotective effect (${\tau}_{50}$) in $^1O_2$-induced erythrocyte hemolysis was 181 min with $4{\mu}g/ml$ of the aglycone fraction. The ${\tau}_{50}$ of the aglycone fraction was approximately 4-times higher than that of (+)-${\alpha}$-tocopherol (${\tau}_{50}$, 41 min). Analysis of $H_2O_2$-induced damage of HaCaT cells revealed that the maximum cell viabilities for the 50% ethanol extract, ethyl acetate fraction, and aglycone fraction were 86.23%, 86.59%, and 89.70%, respectively. The aglycone fraction increased cell viability up to 11.53% at $1{\mu}g/ml$ compared to the positive control treated with $H_2O_2$. Analysis of ultraviolet B radiation-induced HaCaT cell damage revealed up to 41.77% decreased intracellular reactive oxygen species in the $2{\mu}g/ml$ aglycone fraction compared with the positive control treated with ultraviolet B radiation. The findings suggest that the extracts and fractions of A. asphodeloides Bunge have potential applications in the field of cosmetics as natural preservatives and antioxidants.

The Study on the Influence of Capstone Design & Field Training on Employment Rate: Focused on Leaders in INdustry-university Cooperation(LINC) (캡스톤디자인 및 현장실습이 취업률에 미치는 영향: 산학협력선도대학(LINC)을 중심으로)

  • Park Namgue
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.4
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    • pp.207-222
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    • 2023
  • In order to improve employment rates, most universities operate programs to strengthen students' employment and entrepreneurship, regardless of whether they are selected as the Leading Industry-Innovative University (LINC) or not. In particular, in the case of non-metropolitan universities are risking their lives to improve employment rates. In order to overcome the limitations of university establishment type and university location, which absolutely affect the employment rate, we are operating a startup education & startup support program in order to strengthen employment and entrepreneurship, and capstone design & field training as industry-academia-linked education programs are always available. Although there are studies on effectiveness verification centered on LINC (Leaders in Industry-University Cooperation) in previous studies, but a longitudinal study was conducted on all factors of university factors, startup education & startup support, and capstone design & field training as industry-university-linked education programs as factors affecting the employment rate based on public disclosure indicators. No cases of longitudinal studies were reported. This study targets 116 universities that satisfy the conditions based on university disclosure indicators from 2018 to 2020 that were recently released on university factors, startup education & startup support, and capstone design & field training as industry-academia-linked education programs as factors affecting the employment rate. We analyzed the differences between the LINC (Leaders in Industry-University Cooperation) 51 participating universities and 64 non-participating universities. In addition, considering that there is no historical information on the overlapping participation of participating students due to the limitations of public indicators, the Exposure Effect theory states that long-term exposure to employment and entrepreneurship competency enhancement programs will affect the employment rate through competency enhancement. Based on this, the effectiveness of the 2nd LINC+ (socially customized Leaders in Industry-University Cooperation) was verified from 2017 to 2021 through a longitudinal causal relationship analysis. As a result of the study, it was found that the startup education & startup support and capstone design & field training as industry-academia-linked education programs of the 2nd LINC+ (socially customized Leaders in Industry-University Cooperation) did not affect the employment rate. As a result of the longitudinal causal relationship analysis, it was reconfirmed that universities in metropolitan areas still have higher employment rates than universities in non-metropolitan areas due to existing university factors, and that private universities have higher employment rates than national universities. Among employment and entrepreneurship competency strengthening programs, the number of people who complete entrepreneurship courses, the number of people who complete capstone design, the amount of capstone design payment, and the number of dedicated faculty members partially affect the employment rate by year, while field training has no effect at all by year. It was confirmed that long-term exposure to the entrepreneurship capacity building program did not affect the employment rate. Therefore, it was reconfirmed that in order to improve the employment rate of universities, the limitations of non-metropolitan areas and national and public universities must be overcome. To overcome this, as a program to strengthen employment and entrepreneurship capabilities, it is important to strengthen entrepreneurship through participation in entrepreneurship lectures and actively introduce and be confident in the capstone design program that strengthens the concept of PBL (Problem Based Learning), and the field training program improves the employment rate. In order for actually field training affect of the employment rate, it is necessary to proceed with a substantial program through reorganization of the overall academic system and organization.

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