• Title/Summary/Keyword: 유사도 분석

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A Study of the Relationship between Realistic Expression of Objects and Graphic Novel in Korean Comics - Focused on the work by Kwon, Ga-Ya - (한국만화에 있어 대상의 사실적 표현과 그래픽 노블의 연관관계에 대한 연구 - 권가야의 <남한산성>작품을 중심으로 -)

  • Park, Hee-Bok;Kim, Kwang-Su
    • Cartoon and Animation Studies
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    • s.37
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    • pp.361-392
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    • 2014
  • Regarding works that express objects realistically in painting, Gustave Courbet advocated realism in the mid-19th century, France, resisting the then academist style of painting, and works in realist style were produced in earnest by painters such as H. Daumier or Jean F. Millet, who went along with him. Later, realism has expanded into the realm of general literature, including fine art, which has had profound impacts on works of art and literary works. In comics, too, in the same historical context as a form of painting, realistic comics began to be produced by painters or cartoonists at the time. These realism comics are those dealing with stories based on facts, and in terms of contents, objective description and representation of the social realities of the times is one of the most important objectives, but it could not be concluded that in their visual aspect, that is, that of expressing the objects, they were realistic. In the meantime, a graphic novel was born, which was the intermediate form between comics and novels around the United States and Europe since the 1980s. Graphic novels appeared in forms and styles with strong literary and artistic values in the comics market in the U.S. which was full of the superhero genre (comics around heroes), and their major characteristics are very realistic expressions in terms of contents and visual aspect. They are complex and delicate and even have artistic, literary values as if readers read a fiction or literary work of which its narrative structures or pictures are produced with graphics. The characteristics of realistic expressions shown in graphic novels are very different from the previous works of comics. It is noteworthy that they began to be acknowledged as works of art like painting or illustration, thanks to their features of strongly individual auteurist painting style, a fairly high degree of completion of the works, and creative and experimental expression techniques or methods, instead of following the fashion of the times. In recent years, in South Korea, Hollywood blockbuster films have been released one after another and become box office hits, there are increasing interest and demand for the original graphic novels. Accordingly, many original graphic novels have been translated and started to be sold, and keeping pace with this global flow of fashion, some writers in Korea began to produce works of graphic novels. However, to look into the domestic works produced claiming to be graphic novels, there are various opinions on their format and authenticity. In this sense, this study focused on Ga-ya Kwon's Namhansanseong, one the representative works of Korean style graphic novels, and in particular, it attempted to analyze their characteristics and commonalities focusing on the visual aspect of realistic expressions of objects. It is expected that there would be an opportunity to seek for ways so that Korean style graphic novel can be further developed as a genre of comics, with competitiveness by looking back on the identity and present state of domestic graphic novels and developing and applying Korea's original subject matters differentiated from those of graphic novels in the U.S., Europe or Japan through this study. In addition, it is desired that they will be a new energizer for the stagnant domestic comics market.

Factors influencing the axes of anterior teeth during SWA on masse sliding retraction with orthodontic mini-implant anchorage: a finite element study (교정용 미니 임플랜트 고정원과 SWA on masse sliding retraction 시 전치부 치축 조절 요인에 관한 유한요소해석)

  • Jeong, Hye-Sim;Moon, Yoon-Shik;Cho, Young-Soo;Lim, Seung-Min;Sung, Sang-Jin
    • The korean journal of orthodontics
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    • v.36 no.5
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    • pp.339-348
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    • 2006
  • Objective: With development of the skeletal anchorage system, orthodontic mini-implant (OMI) assisted on masse sliding retraction has become part of general orthodontic treatment. But compared to the emphasis on successful anchorage preparation, the control of anterior teeth axis has not been emphasized enough. Methods: A 3-D finite element Base model of maxillary dental arch and a Lingual tipping model with lingually inclined anterior teeth were constructed. To evaluate factors influencing the axis of anterior teeth when OMI was used as anchorage, models were simulated with 2 mm or 5 mm retraction hooks and/or by the addition of 4 mm of compensating curve (CC) on the main archwire. The stress distribution on the roots and a 25000 times enlarged axis graph were evaluated. Results: Intrusive component of retraction force directed postero-superiorly from the 2 mm height hook did not reduce the lingual tipping of anterior teeth. When hook height was increased to 5 mm, lateral incisor showed crown-labial and root-lingual torque and uncontrolled tipping of the canine was increased.4 mm of CC added to the main archwire also induced crown-labial and root-lingual torque of the lateral incisor but uncontrolled tipping of the canine was decreased. Lingual tipping model showed very similar results compared with the Base model. Conclusion: The results of this study showed that height of the hook and compensating curve on the main archwire can influence the axis of anterior teeth. These data can be used as guidelines for clinical application.

The Effect of Korean Soysauce and Soypaste Making on Soybean Protein Quality Part II. Chemical Changes During Meju-brine Ripening (재래식 간장 및 된장 제조가 대두 단백질의 영양가에 미치는 영향 제2보 메주장의 숙성중에 일어나는 성분 변화)

  • Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
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    • v.8 no.1
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    • pp.19-32
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    • 1976
  • The laboratory Mejus as well as home-made Meju and improved Meju received from Korea were ripened in the brine for up to 8 months and the changes is the chemical composition during the process were determined and the differences between the types of Meju were compared. On the basis of the amino acid pattern, the changes in the protein quality of soybean during the process was evaluated. No significant changes in the general chemical composition of Meju were noticed during the ripening for 8 months. However, the nitrogen solubility of Meju increased for $13{\sim}29%$ to $66{\sim}78%$ during 8 month ripening of the Meju-brine mixture. The concentration of free amino-N to the total-N increased from $4{\sim}7%$ in Meju to $29{\sim}35%$ in the 8month ripened mixture. The concentration of amino-N to the total-N increased from $1{\sim}4%$ in Meju to $5{\sim}14%$ in the 8month ripened mixture and the changes varied with the type of Meju used. Remarkable changes in the amino acid pattern of soybean were occured during the ripening process. The concentration of methionine decreased to the half of original Meju during the first month of ripening. Arginine and histidine were destroyed rapidly by the ripening longer than 1 month. A considerable amount of ornithine was synthesized during the ripening. The amino acid pattern of Meju did change drastically during the ripening longer than 3 months and the changes varied with the type of Meju. The retention of the nutrients in soybean during 8 month ripening of the laboratory 3 month Meju in the brine was 49% for carbohydrates, 107% for crude fat, 93% for crude protein and 74% for the total amino acid. Histidine, arginine and methionine and 74% for the total amino acid. Histidine, arginine and methionine were the most damaged during the process, retaining only 25%, 27% and 49% of the contents in raw soybean, respectively, whereas lysine retained 79%. By the separation of the 8 month ripened mixture, approximately 60% of crude protein, all of crude fat and 80% of carbohydrates in the mixture were retained in soypaste. Soypaste contained higher concentrations of amino acids per 16gN compared to soysauce, except for lysine. The most limiting amino acid of the protein was the S-containing amino acids in all cases studied, whereas the second limiting amino acid varied from valine in soybean to threonine in most of Mejus and the brine mixtures, lysine in most of soypastes and tryptophan in some of soysauces. According to the protein quality evaluation made by the reference of the FAO provisional pattern of amino acid, the chemical score of raw soybean was 82, which was reduced to 77 by cooking and further reduced to $71{\sim}74$ by Meju fermentation. At the eighth month of ripening the chemical score of the Meju-brine mixtures were reduced to $51{\sim}66. After the separation, the chemical score of soypaste ranged from 60 to 71, whereas that of soysauce varied from 45 to 57. Generally, the products made from improved Meju recorded the highest score, whereas those made from homemade Meju showed the poorest protein quality. The essential amino acid index(EAAI) of the samples was similar to the chemical score, but it appeared to fit the overall changes in the amino acid pattern during the process better than the chemical score.

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In Vitro Properties and Biodistribution of Tc-99m and Re-188 Labeled Monoclonal Antibody CEA79.4 (Re-188과 Tc-99m 표지 단일클론항체 CEA79.4의 생체외 특성과 생체내 분포)

  • Hong, Mee-Kyoung;Jeong, Jae-Min;Yeo, Jeong-Seok;Kim, Kyung-Min;Chang, Young-Soo;Lee, Yong-Jin;Lee, Dong-Soo;Chung, June-Key;Lee, Myung-Chul;Lee, Seung-Jin
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.6
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    • pp.516-524
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    • 1998
  • Purpose: Radiolabeled CEA79.4 antibody has a possibility to be used in radioimmunoscintigraphy or radioimmunotherapy of cancer. We investigated the in vitro properties and biodistribution of CEA79.4 antibody labeled with Re-188 or Tc-99m. Materials and Methods: CEA79.4 was reduced by 2-mercaptoethanol to produce-SH residue, and was labeled with Re-188 or Tc-99m. For direct labeling of Tc-99m, methylene-diphosphonate was used as transchelating agent. CEA79.4 in 50 mM Acetate Buffered Saline (ABS, pH 5.3) was labeled with Re-188, using stannous tartrate as reducing agent. In order to measure immunoreactivity and the affinity constant of radiolabeled antibody, cell binding assay and Scatchard analysis using human colon cancer cells SNU-C4, were performed. Biodistribution study of labeled CEA79.4 was carried out at 1, 14 and 24 hr in ICR mice. Results: Labeling efficiencies of Tc-99m and Re-188 labeled antibodies were $92.4{\pm}5.9%$ and $84.7{\pm}4.6%$, respectively, In vitro stability of Tc-99m-CEA79.4 in human serum was higher than Re-188-CEA79.4. Immunoreactivity and affinity constant of Tc-99m-CEA79.4 were 59.2% and $6.59{\times}10^9\;M^{-1}$, respectively, while those of Re-188-CEA79.4 were 41.6% and $4.2{\times}10^9\;M^{-1}$, respectively. After 24 hr of administrations of Re-188 and Tc-99m labeled antibody, the remaining antibodies in blood were 6.32 and 9.35% ID/g respectively. The biodistribution of each labeled antibody in other organs was similar because they did not accumulate in non-targeted organs. Conclusion: In vitro properties and biodistribution of Re-188-CEA79.4 were similar to those of Tc-99m-CEA79.4. It appears that Re-188-CEA79.4 can be used as a suitable agent for radioimmunotheraphy.

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Effects of Anti-thyroglobulin Antibody on the Measurement of Thyroglobulin : Differences Between Immunoradiometric Assay Kits Available (면역방사계수법을 이용한 Thyroglobulin 측정시 항 Thyroglobulin 항체의 존재가 미치는 영향: Thyroglobulin 측정 키트에 따른 차이)

  • Ahn, Byeong-Cheol;Seo, Ji-Hyeong;Bae, Jin-Ho;Jeong, Shin-Young;Yoo, Jeong-Soo;Jung, Jin-Hyang;Park, Ho-Yong;Kim, Jung-Guk;Ha, Sung-Woo;Sohn, Jin-Ho;Lee, In-Kyu;Lee, Jae-Tae;Kim, Bo-Wan
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.4
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    • pp.252-256
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    • 2005
  • Purpose: Thyroglobulin (Tg) is a valuable and sensitive tool as a marker for diagnosis and follow-up for several thyroid disorders, especially, in the follow-up of patients with differentiated thyroid cancer (DTC). Often, clinical decisions rely entirely on the serum Tg concentration. But the Tg assay is one of the most challenging laboratory measurements to perform accurately owing to antithyroglobulin antibody (Anti-Tg). In this study, we have compared the degree of Anti-Tg effects on the measurement of Tg between availale Tg measuring kits. Materials and Methods: Measurement of Tg levels for standard Tg solution was performed with two different kits commercially available (A/B kits) using immunoradiometric assay technique either with absence or presence of three different concentrations of Anti-Tg. Measurement of Tg for patient's serum was also performed with the same kits. Patient's serum samples were prepared with mixtures of a serum containing high Tg levels and a serum containg high Anti-Tg concentrations. Results: In the measurements of standard Tg solution, presence of Anti-Tg resulted in falsely lower Tg level by both A and B kits. Degree of Tg underestimation by h kit was more prominent than B kit. The degree of underestimation by B kit was trivial therefore clinically insignificant, but statistically significant. Addition of Anti-Tg to patient serum resulted in falsely lower Tg levels with only A kit. Conclusion: Tg level could be underestimated in the presence of anti-Tg. Anti-Tg effect on Tg measurement was variable according to assay kit used. Therefore, accuracy test must be performed for individual Tg-assay kit.

A Study on the Factors Influencing Technology Innovation Capability on the Knowledge Management Performance of the Company: Focused on Government Small and Medium Venture Business R&D Business (기술혁신역량이 기업의 지식경영성과에 미치는 요인에 관한 연구: 정부 중소벤처기업 R&D사업을 중심으로)

  • Seol, Dong-Cheol;Park, Cheol-Woo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.4
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    • pp.193-216
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    • 2020
  • Due to the recent mid- to long-term slump and falling growth rates in the global economy, interest in organizational structures that create new products or services as a new alternative to survive and develop in an opaque environment both internally and externally, and enhance organizational sustainability through changes in production methods and business innovation is increasing day by day. In this atmosphere, we agree that the growth of small and medium-sized venture companies has a significant impact on the national economy, and various efforts are being made to enhance the technological innovation capabilities of the members so that these small and medium-sized venture companies can enhance and sustain their performance. The purpose of this study is also to investigate how the technological innovation capabilities of small and medium-sized venture companies correlate with the performance of knowledge management and to analyze the role of network capabilities to organize the strategic activities of enterprise to obtain the resources and organizational capabilities to be used for value creation from external networks. In other words, research was conducted on the impact of technological innovation capabilities of small and medium venture companies on knowledge management performance by using network capabilities as parameters. Therefore, in this study, we would like to verify the hypothesis that innovation capabilities will have a positive impact on knowledge management performance by using network capabilities of small and medium venture companies. Economic activities based on technological innovation capabilities should respond quickly to new changes in an environment where uncertainty has increased, and lead to macro-economic growth and development as well as overcoming long-term economic downturns so that they can become the nation's new growth engine as well as sustainable growth and survival of the organization. In addition, this study was conducted by setting the most important knowledge management performance within the organization as a dependent variable. As a result, R&D and learning capabilities among technological innovation capabilities have no impact on financial performance. In contrast, it was shown that corporate innovation activities have a positive impact on both financial and non-financial performance. The fact that non-financial factors such as quality and productivity improvement are identified in the management of small and medium-sized venture companies utilizing their technological innovation capabilities is contrary to a number of studies by those corporate innovation activities affect financial performance during prior research. The reason for this result is that research companies have been out of start-up companies for more than seven years, but sales are less than 10 billion won, and unlike start-up companies, R&D and learning capabilities have more positive effects on intangible non-financial performance than financial performance. Corporate innovation activities have been shown to have a positive (+) impact on both financial and non-financial performance, while R&D and learning capabilities have a positive (+) impact on financial performance by parameters of network capability. Corporate innovation activities have been shown to have no impact on both financial and non-financial performance, and R&D and learning capabilities have no impact on non-financial performance. It could be seen that the parameter effects of network competency are limited to when R&D and learning competencies are derived from quantitative financial performance. It could be seen that the parameter effects of network competency are limited to when R&D and learning competencies are derived from quantitative financial performance.

Choline and Betaine Concentrations in Breast Milk of Korean Lactating Women and the Choline and Betaine Intakes of Their Infants (한국 수유부 유즙의 콜린과 베타인 농도 및 영아의 콜린과 베타인 섭취량)

  • Jeong, Han-Ok;Suh, Yoon-Suk;Chung, Young-Jin
    • Journal of Nutrition and Health
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    • v.43 no.6
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    • pp.588-596
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    • 2010
  • Most nutrients taken by pregnant women are secreted into their breast milk. Food contains choline together with betaine, and in human body choline is oxidized to betaine which transfer methyl group. The aim of the study was to estimate the concentrations of choline and betaine in breast milk of Korean lactating women and the choline and betaine intakes of their infants. Total choline, free choline and betaine concentrations in breast milk of some lactating women living in Daejon Metropolitan city were analyzed every month by using HPLC-MS and enzymatic method during the first five months. Total choline concentrations of breast milks were 157.64 mg/L (1.52 mmol/L), 157.83 mg/L (1.52 mmol/L), 165.99 mg/L (1.60 mmol/L), 153.67 mg/L (1.48 mmol/L), 145.05 mg/L (1.39 mmol/L) by month after delivery for five months. The concentrations of total choline and free choline in breast milks were not significantly changed for the five months while the betaine concentrations gradually decreased. Daily intake of total choline of the infants appears to be adequate for the infant's requirement according to the US DRI; 124.6 mg/d, 120.9 mg/d, 126.5 mg/d 104.1 mg/d from 2nd to 5th month after birth. Free choline and betaine intakes of the infants were not significantly changed during the four months except showing decrease in betaine intake per kg body weight. Choline intakes of the infants more correlated with choline concentrations of the breast milks (r = 0.982, p = 0.000) than intake amount of the breast milk (r = 0.414, p = 0.028). These results suggest that the choline intake of Korean breast-fed infants appears to be adequate and the intake could be affected by the choline concentration of the breast milk.

The Effect of Brand Extension of Private Label on Consumer Attitude - a focus on the moderating effect of the perceived fit difference between parent brands and an extended brand - (PL의 브랜드확장이 소비자태도에 미치는 영향에 관한 연구 : 모브랜드 적합도 인식 차이의 조절효과를 중심으로)

  • Kim, Jong-Keun;Kim, Hyang-Mi;Lee, Jong-Ho
    • Journal of Distribution Research
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    • v.16 no.4
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    • pp.1-27
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    • 2011
  • Introduction: Sales of private labels(PU have been growing m recent years. Globally, PLs have already achieved 20% share, although between 25 and 50% share in most of the European markets(AC. Nielson, 2005). These products are aimed to have comparable quality and prices as national brand(NB) products and have been continuously eroding manufacturer's national brand market share. Stores have also started introducing premium PLs that are of higher-quality and more reasonably priced compared to NBs. Worldwide, many retailers already have a multiple-tier private label architecture. Consumers as a consequence are now able to have a more diverse brand choice in store than ever before. Since premium PLs are priced higher than regular PLs and even, in some cases, above NBs, stores can expect to generate higher profits. Brand extensions and private label have been extensively studied in the marketing field. However, less attention has been paid to the private label extension. Therefore, this research focuses on private label extension using the Multi-Attribute Attitude Model(Fishbein and Ajzen, 1975). Especially there are few studies that consider the hierarchical effect of the PL's two parent brands: store brand and the original PL. We assume that the attitude toward each of the two parent brands affects the attitude towards the extended PL. The influence from each parent brand toward extended PL will vary according to the perceived fit between each parent brand and the extended PL. This research focuses on how these two parent brands act as reference points to one another in the consumers' choice consideration. Specifically we seek to understand how store image and attitude towards original PL affect consumer perceptions of extended premium PL. How consumers perceive extended premium PLs could provide strategic suggestions for retailer managers with specific suggestions on whether it is more effective: to position extended premium PL similarly or dissimilarly to original PL especially on the quality dimension and congruency with store image. There is an extensive body of research on branding and brand extensions (e.g. Aaker and Keller, 1990) and more recently on PLs(e.g. Kumar and Steenkamp, 2007). However there are no studies to date that look at the upgrading and influence of original PLs and attitude towards store on the premium PL extension. This research wishes to make a contribution to this gap using the perceived fit difference between parent brands and extended premium PL as the context. In order to meet the above objectives, we investigate which factors heighten consumers' positive attitude toward premium PL extension. Research Model and Hypotheses: When considering the attitude towards the premium PL extension, we expect four factors to have an influence: attitude towards store; attitude towards original PL; perceived congruity between the store image and the premium PL; perceived similarity between the original PL and the premium PL. We expect that all these factors have an influence on consumer attitude towards premium PL extension. Figure 1 gives the research model and hypotheses. Method: Data were collected by an intercept survey conducted on consumers at discount stores. 403 survey responses were attained (total 59.8% female, across all age ranges). Respondents were asked to respond to a series of Questions measured on 7 point likert-type scales. The survey consisted of Questions that measured: the trust towards store and the original PL; the satisfaction towards store and the original PL; the attitudes towards store, the original PL, and the extended premium PL; the perceived similarity of the original PL and the extended premium PL; the perceived congruity between the store image and the extended premium PL. Product images with specific explanations of the features of premium PL, regular PL and NB we reused as the stimuli for the Question response. We developed scales to measure the research constructs. Cronbach's alphaw as measured each construct with the reliability for all constructs exceeding the .70 standard(Nunnally, 1978). Results: To test the hypotheses, path analysis was conducted using LISREL 8.30. The path analysis for verification of the model produced satisfactory results. The validity index shows acceptable results(${\chi}^2=427.00$(P=0.00), GFI= .90, AGFI= .87, NFI= .91, RMSEA= .062, RMR= .047). With the increasing retailer use of premium PLBs, the intention of this research was to examine how consumers use original PL and store image as reference points as to the attitude towards premium PL extension. Results(see table 1 & 2) show that the attitude of each parent brand (attitudes toward store and original pL) influences the attitude towards extended PL and their perceived fit moderates these influences. Attitude toward the extended PL was influenced by the relative level of perceived fit. Discussion of results and future direction: These results suggest that the future strategy for the PL extension needs to consider that positive parent brand attitude is more strongly associated with the attitude toward PL extensions. Specifically, to improve attitude towards PL extension, building and maintaining positive attitude towards original PL is necessary. Positioning premium PL congruently to store image is also important for positive attitude. In order to improve this research, the following alternatives should also be considered. To improve the research model's predictive power, more diverse products should be included in study. Other attributes of product should also be included such as design, brand name since we only considered trust and satisfaction as factors to build consumer attitudes.

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Developmental Plans and Research on Private Security in Korea (한국 민간경비 실태 및 발전방안)

  • Kim, Tea-Hwan;Park, Ok-Cheol
    • Korean Security Journal
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    • no.9
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    • pp.69-98
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    • 2005
  • The security industry for civilians (Private Security), was first introduced to Korea via the US army's security system in the early 1960's. Shortly after then, official police laws were enforced in 1973, and private security finally started to develop with the passing of the 'service security industry' law in 1976. Korea's Private Security industry grew rapidly in the 1980's with the support of foreign funds and products, and now there are thought to be approximately 2000 private security enterprises currently running in Korea. However, nowadays the majority of these enterprises are experiencing difficulties such as lack of funds, insufficient management, and lack of control over employees, as a result, it seems difficult for some enterprises to avoid the low production output and bankruptcy. As a result of this these enterprises often settle these matters illegally, such as excessive dumping or avoiding problems by hiring inappropriate employees who don't have the right skills or qualifications for the jobs. The main problem with the establishment of this kind of security service is that it is so easy to make inroads into this private service market. All these hindering factors inhibit the market growth and impede qualitative development. Based on these main reasons, I researched this area, and will analyze and criticize the present condition of Korea's private security. I will present a possible development plan for the private security of Korea by referring to cases from the US and Japan. My method of researching was to investigate any related documentary records and articles and to interview people for necessary evidence. The theoretical study, involves investigation books and dissertations which are published from inside and outside of the country, and studying the complete collection of laws and regulations, internet data, various study reports, and the documentary records and the statistical data of many institutions such as the National Police Office, judicial training institute, and the enterprises of private security. Also, in addition, the contents of professionals who are in charge of practical affairs on the spot in order to overcomes the critical points of documentary records when investigating dissertation. I tried to get a firm grasp of the problems and difficulties which people in these work enterprises experience, this I thought would be most effective by interviewing the workers, for example: how they feel in the work places and what are the elements which inpede development? And I also interviewed policemen who are in charge of supervising the private escort enterprises, in an effort to figure out the problems and differences in opinion between domestic private security service and the police. From this investigation and research I will try to pin point the major problems of the private security and present a developmental plan. Firstly-Companies should unify the private police law and private security service law. Secondly-It is essential to introduce the 'specialty certificate' system for the quality improvement of private security service. Thirdly-must open up a new private security market by improving old system. Fourth-must build up the competitive power of the security service enterprises which is based on an efficient management. Fifth-needs special marketing strategy to hold customers Sixth-needs positive research based on theoretical studies. Seventh-needs the consistent and even training according to effective market demand. Eighth-Must maintain interrelationship with the police department. Ninth-must reinforce the system of Korean private security service association. Tenth-must establish private security laboratory. Based on these suggestions there should be improvement of private security service.

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Fly Ash Application Effects on CH4 and CO2 Emission in an Incubation Experiment with a Paddy Soil (항온 배양 논토양 조건에서 비산재 처리에 따른 CH4와 CO2 방출 특성)

  • Lim, Sang-Sun;Choi, Woo-Jung;Kim, Han-Yong;Jung, Jae-Woon;Yoon, Kwang-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.5
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    • pp.853-860
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    • 2012
  • To estimate potential use of fly ash in reducing $CH_4$ and $CO_2$ emission from soil, $CH_4$ and $CO_2$ fluxes from a paddy soil mixed with fly ash at different rate (w/w; 0, 5, and 10%) in the presence and absence of fertilizer N ($(NH_4)_2SO_4$) addition were investigated in a laboratory incubation for 60 days under changing water regime from wetting to drying via transition. The mean $CH_4$ flux during the entire incubation period ranged from 0.59 to $1.68mg\;CH_4\;m^{-2}day^{-1}$ with a lower rate in the soil treated with N fertilizer due to suppression of $CH_4$ production by $SO_4^{2-}$ that acts as an electron acceptor, leading to decreases in electron availability for methanogen. Fly ash application reduced $CH_4$ flux by 37.5 and 33.0% in soils without and with N addition, respectively, probably due to retardation of $CH_4$ diffusion through soil pores by addition of fine-textured fly ash. In addition, as fly ash has a potential for $CO_2$ removal via carbonation (formation of carbonate precipitates) that decreases $CO_2$ availability that is a substrate for $CO_2$ reduction reaction (one of $CH_4$ generation pathways) is likely to be another mechanisms of $CH_4$ flux reduction by fly ash. Meanwhile, the mean $CO_2$ flux during the entire incubation period was between 0.64 and $0.90g\;CO_2\;m^{-2}day^{-1}$, and that of N treated soil was lower than that without N addition. Because N addition is likely to increase soil respiration, it is not straightforward to explain the results. However, it may be possible that our experiment did not account for the substantial amount of $CO_2$ produced by heterotrophs that were activated by N addition in earlier period than the measurement was initiated. Fly ash application also lowered $CO_2$ flux by up to 20% in the soil mixed with fly ash at 10% through $CO_2$ removal by the carbonation. At the whole picture, fly ash application at 10% decreased global warming potential of emitted $CH_4$ and $CO_2$ by about 20%. Therefore, our results suggest that fly ash application can be a soil management practice to reduce green house gas emission from paddy soils. Further studies under field conditions with rice cultivation are necessary to verify our findings.