• Title/Summary/Keyword: Potential Problem

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Optimization of growth conditions for cultivation of Phellinus linteus mycelia using swine waste as a growth substrate (돈분뇨를 기질로 활용한 고부가 가치 상황버섯 균사체 배양조건 최적화 연구)

  • Koo, Taewoan;Lee, Joonyeob;Cho, Kyungjin;Lee, Jangwoo;Shin, Seung Gu;Hwang, Seokhwan
    • Journal of the Korea Organic Resources Recycling Association
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    • v.23 no.2
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    • pp.53-60
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    • 2015
  • Newly, nutrients recovery by bioconversion in the swine waste which caused serious problems due to its high organic fraction and content of nutrients such as phosphorus and nitrogen is viewed as a considerable approach since it produces valuable product as well as recycling of resources. Consequently, it is necessary to find new methods to treat swine waste. One possible solution to this problem is to use this potential pollutant as a growth substrate for economically valuable products. The study for the fundamental improvement of bioconversion efficiency by finding optimum growth conditions using statistical models and biotechnology was performed. A novel approach to utilize swine waste by cultivating mycelia of the mushroom Phellinus linteus are described. A central composite face-centered design (CCF) for the experiments was used to develop empirical model providing a quantitative interpretation of the relationships among the three variables, which were substrate concentration, pH, and temperature. The maximal radial extension rate (2.78mm/d) of P.linteus was determined under the condition of 5.0 g COD/L, pH 5.0, and temperature $29.7^{\circ}C$. The results of this study suggest that swine waste could be utilized as a growth substrate for the cultivation of mushroom mycelia enhancing an efficiency of utilizing this by-product of the livestock industry.

The Road Subsidence Status and Safety Improvement Plans (도로함몰 실태와 안전관리 개선 방안)

  • Bae, Yoon-Shin;Kim, Kyoon-Tai;Lee, Sang-Yum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.545-552
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    • 2017
  • Ground subsidence can result in the formation of sinkholes, potholes, settlement of structures, and road subsidence. Road subsidence is described as the sudden collapse of the road surface into subsurface cavities caused by the loss of bearing capacity in the ground, such as the dissolution of limestone by fluid flow in the surface causing the formation of voids leading to subsidence at the surface. Road subsidence occurs about 665 times annually, and this incidence has been increasing until 2013. Damaged underground facilities, management negligence, and lowering of the ground water table have been the causes of road subsidence in Seoul. Seoul metropolitan government announced special management counter plans to relieve the anxieties and make the roads safe for passing. Construction sites, such as excavation works, need to be managed properly because they have strong potential to induce road subsidence. The aim of this study was to identify the main causes of road subsidence and suggest management plans. First, life cycle cost analysis revealed the daytime construction to be more appropriate than nighttime. In addition, by analyzing the limitations of using sand as a backfill material, it is proposed to use a flowable backfill material instead of sand. Finally, to reduce the blind spots, which is a problem in surveying the road pavement conditions of local governments, the road to be managed is divided into several zones, and a specialized agency is selected for each zone and a method of surveying the blind spots through collaboration is suggested.

Analysis for the Correlations between health Problems and Computer Game Needs in the Elderly (노인들의 건강문제와 컴퓨터 게임 요구도의 상관성 분석)

  • Lim, Kyung-Choon;Lee, Yoon-Jung;Ahn, Joon-Hee
    • The Journal of the Korea Contents Association
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    • v.9 no.11
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    • pp.475-486
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    • 2009
  • Regular activity program is needed for managing chronic disease and obesity and preventing falls as a nursing intervention. It seems that serious game will be very important for older people to keep them active with fun to improve their health. This study was conducted to explore the correlations between health problems and computer game needs in the elderly. This was a cross-sectional study. A questionnaire was developed and administered to a convenience sample of adults who are older than 55 years, recruited from several places through trained research assistants and research center that has online pools in Korea. 778 subjects (mean age: $61.4\;{\pm}\;5.6$) were participated in this study. The majority of subjects was male (68.6%). We found that there was higher needs for exercise or serious game in the group of ma1e(55.4%), below undergraduate(66.2%), under two family members(32.5%), over 350,000 won of pocket money/month (40.1%), mild depressive symptom (51.7%), and online responser(68%). Especially, they wanted to overcome physical limitations through games. Higher education, more experiences and skills of using computer/internet was statistically and positively significant to the needs for exercise or serious game. In conclusion, there exists a potential market within this demographic group for the use of serious games. Thus, we need to develop senior games in Korean to improve quality of life and health promotion.

A Reduction Effect in Noise Reflection by Different Shapes of Soundproofing-panel (도로소음원에 대한 방음패널 형상별 반사소음 저감효과)

  • Kim, Ilho;Park, Taeho;Chang, Seoil;Lee, Haein
    • Journal of Korean Society of Environmental Engineers
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    • v.37 no.2
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    • pp.120-125
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    • 2015
  • With rapid urbanization, the volume of traffic in urban area has been significantly increased. This in turn led to problem which can be described as Road Traffic Noise. Currently, to alleviate the road traffic noise damage, a demand for installation of soundproofing walls is rising. Among different shapes of soundproof walls being installed, the reflection-type acoustical insulation panel is highly drawing attentions of residents due to the fact that it does not obstruct their field of vision in contrast with the opaque acoustical insulation panel. On the other hand, improving the soundproofing wall of the reflection-type acoustical insulation barrier panel needs to be focused on since it has a possibility to cause a secondary damage by reflected sounds. Therefore, in this research, study has been carried out to improve the forms in order to minimize travelling of reflected sounds through changing the frontal surface shape and geometrical shape of the reflection-type soundproofing panel. A result from comparison between the normal reflection-type soundproofing panel and the improved soundproofing panel, with reduction effects in the noise reflection, showed that the curved type of soundproofing panel has an impact on reducing the noise up to 1.5 dB. Furthermore, from the research conducted, it appears that the increase and decrease in the reflected sounds can be changeable depending on various design factors. Thus, it turns out that the study shows a potential possibility to develop a reduction technology of the reflected sounds pertaining to overall condition on the soundproofing walls.

Review on Risks of Perchlorate and Treatment Technologies (퍼클로레이트(Perchlorate)의 위해성과 저감기술 소개)

  • Shin, Kyung-Hee;Son, Ah-Jeong;Cha, Daniel K.;Kim, Kyoung-Woong
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.9
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    • pp.1060-1068
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    • 2007
  • Perchlorate contamination in aquatic system is a growing concern due to the human health and ecological risks associated with perchlorate exposure. In spite of potential risks associated with perchlorate, drinking water standard has not been established worldwide. Recently, US EPA has issued new protective guidance for cleaning up perchlorate contamination with a preliminary clean-up goal of 24.5 ppb. In Korea, the drinking water standard and discharge standard for perchlorate has not been established yet and little information is available to address perchlorate problems. Perchlorate treatment technologies include ion exchange, microbial reactor, carbon adsorption, composting, in situ bioremediation, permeable reactive barrier, phytoremediation, and membrane technology. The process description, capability, and advantage/disadvantages of each technology were described in detail in this review. One of recent trends in perchlorate treatment is the combination of available treatment options such as combined microbial reduction and permeable reactive burier. In this review, we provided a brief perspective on perchlorate treatment technology and to identify an efficient and cost-effective approach to manage perchlorate problem.

The Research of Process High Alarm Priority Analysis for Efficient Emergency Response (효율적인 비상대응을 위한 Process High Alarm의 Priority 분석)

  • Kim, Youngse;Cho, Gyusun;Jun, Jinwoo;Kim, Byungjick;Lee, Joonwon;Park, Kyoshik
    • Korean Chemical Engineering Research
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    • v.58 no.4
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    • pp.604-609
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    • 2020
  • The purpose of this study is to check the priority control status of the current operation process alarm by comparing the priority of the alarm set up in PV high trip point, which is being installed and operated in the domestic petrochemical industry, with the criteria presented in ISA 18.2 International Standard or EEMUA 191 Guidelines. In the event of a process problem, excessively set high alarm is provided to the driver in a short period of time, making it difficult to identify the alarm that needs to be handled first. As a result, it is likely that the operator will not be able to carry out appropriate actions within the specified time frame, and many cases have been reported leading to unexpected process shutdowns or process accidents. Therefore, this study aims to introduce international standards related to alarm management and identify the level of alarm control used at the domestic petrochemical industry site to inform potential risks that may occur in the petrochemical process of the national industrial complex in the future and suggest ways to reduce risk factors. This paper was submitted to Professor Lee Inbeom's retirement anniversary issue.

A Study on Combustion and Emission Characteristics of a Diesel Engine Fuelled with Pyrolysis Oil-Ethanol and Pilot Diesel (바이오원유-에탄올/파일럿 디젤유 이종연료 혼소를 통한 디젤엔진의 연소 및 배출가스 특성에 관한 연구)

  • Kim, Min-Jae;Lee, Seok-Hwan;Cho, Jeong-Kwon;Yoon, Jun-Kyu;Lim, Jong-Han
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.5
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    • pp.420-427
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    • 2017
  • Recently, the depletion of fossil fuels, global warming and environmental pollution have emerged as a worldwide problem, and studies of new renewable energy sources have been progressed. Among the many renewable energy sources, the use of bio fuel has the potential to displace fossil fuels due to low price, easy to handle, and the abundant sources. Pyrolysis oil (PO) derived from waste wood and sawdust is considered an alternative fuel for use in diesel engines. On the other hand, PO is limited to diesel engines because of its low cetane number, high viscosity, high acidity, and low energy density. Therefore, to improve its poor properties, PO was mixed with alcohol fuels, such as ethanol. Early mixing with ethanol has the benefit of improving the storage and handling properties of the PO. Furthermore, a PO-ethanol blended fuel was injected separately, which can be fired through pilot-injected diesel in a dual-injection diesel engine. The experimental results showed that the substitution of diesel with blended fuel increases the amount of HC and CO, but reduces the NOx and PM significantly.

Study on the Realities in Seoul Subway Crimes: Criminal Psychology (서울지하철 범죄 실태에 대한 범죄심리학적 연구)

  • Rim, Sang-Gon
    • Korean Security Journal
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    • no.7
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    • pp.233-285
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    • 2004
  • ‘Defined legally as a violation of law' (Sutherland, E. H. Principles of Criminology, Lippincott, Chicago, 1939) Crime within the group is essentially and primarily antisocial in that the criminal who is welfare of his group acts instead against it and breaks the principles of social solidarity not merely by not doing what these principles prescribe, but by doing something exactly opposites. Any program set up to attack crime and delinquent behavior at their sources. A program of his nature needs the constant and comprehensive collaboration of psychiatrists, social works, educations, lawmakers, and public officials, since crime is a social problem and it should be treated as such. Some crime preventives which should be mentioned are as follows, (1) The insurance that every child will be decently born and that his home life be socially and economically adequate; without socially mature parents the chid is handicapped at the start; thus parental education, integrated with the public school system, should be developed now. (2) A more meaningful educational program which would emphasize ideals of citizenship, moral integrity, and respect for the law and the police. (3) A periodic check made for potential delinquents throughout the public schools and treatment provided if possible; and if not, proper segregation in institutions. (4) Careful attention paid to press, movies, and radio so that crime may no longer appear to be glamorous. This can be done by women's clubs, civic bodies, and other educational groups exerting pressure on the movie syndicates and broadcasting companies to free their productions of the tawdry and lurid characteristics of crime and criminals. Aggression associated with the phallic stage of development, The child ordinarily comprehends sexual intercourse as an aggressive and sadistic act on the part of the male, and specifically on the part of the penis. Evidence that the penis is phantasied as a weapon of violence and destruction come from unconscious productions of normal adults. Limerick, for instance, often refer to the penis as square, or too large, etc., so that intercourse is dangerous and painful for the partner, This may wall be a projection of the male's own fear of coitus. A certain portion of the death-instinct always remains within the person; it is called 'primal sadism' and according to Freud is identical with masochism. 'After the chief part of it(the death instinct) has been directed outwards towards objects, there remains as a residuum within the organism the true erotogenic masochism, which on the one hand becomes a component of the libido and on the other still has the subject itself for a object.' Criminalism, compulsive-neurotic frequent repetition of criminal acts in a compulsive manner. Like most symptoms of the compulsive-neurotic, such antisocial act are closely rated to feelings of hostility and aggression, often against the father. Because these acts are symptomatic, they afford only temporary relief and are therefore repeated. One patient with compulsive-neurotic criminalism was apprehended after breaking into hardware store and stealing money. He later confessed to many similar incidents over the preceding two years. At the same time it was apparent that he stole only for the sake of stealing. He did not need the money he thus obtained and had no special plans for using it.

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Development of a Method to Analyze Powering Performance of a Ship and its Application to Optimum Hull Form Design (선박(船舶)의 정수중(靜水中) 추진성능(推進性能) 해석(解析) 및 최적선형설계(最適船型設計)에의 응용(應用))

  • Seung-Il,Yang
    • Bulletin of the Society of Naval Architects of Korea
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    • v.22 no.2
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    • pp.35-48
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    • 1985
  • The present work develops a method of evaluating thrust deduction and wake for different loads of the propeller using the concerted application of the theoretical tools and experimental techniques. It also shows the applicability of the new method to the design of optimum hull form. Firstly, the problem of hull-propeller interaction was analyzed in terms of inviscid as well as viscous components of the thrust deduction and wake. The wavemaking resistance of a hull and propeller were mathematically represented by sources on the hull surface and sink on the propeller plane, respectively. The strength of sink was determined by utilizing the radial distributions of propeller load and nominal wake. The resistance increment due to a propeller and the axial perturbation flow induced by the hull in the propeller plane were calculated. Especially, the inviscid component of the thrust deduction was calculated by subtraction the wavemaking resistance of a bare hull, the wavemaking resistance of a free-running propeller and the augmentation of propeller resistance due to hull action from the wavemaking resistance of the hull with a propeller. The viscous components of the thrust deduction and wake were estimated as functions of propeller load which were established by the propeller load varying test after deduction the calculated inviscid components. Secondly, an analysis method of powering performance was developed based on the potential theory and the propeller load varying test. The hybrid method estimates the thrust deduction, wake and propeller open-water efficiency for different propeller load. This method can be utilized in the analysis of powering performance for the propeller load variation such as the added resistance due to hull surface roughness, the added resistance due to wind, etc. Finally, the hybrid method was applied to the optimum design of hull form. A series of afterbody shapes was obtained by systematically varying the waterplane and section shapes of a parent afterbody without changing the principal dimensions, block coefficient and prismatic coefficient. From the comparison of the predicted results such as wavemaking resistance, thrust deduction, wake and delivered power, an optimum hull form was obtained. The delivered power of the optimized hull form was reduced by 5.7% which was confirmed by model tests. Also the predicted delivered power by the hybrid method shows fairly good agreement with the test result. It is therefore considered that the new analysis method of powering performance can be utilized as a practical tool for the design of optimum hull form as for the analysis of powering performance for the propeller load variation in the preliminary design stage.

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An Application of FCM(Fuzzy C-Means) for Clustering of Asian Ports Competitiveness Level and Status of Busan Port (FCM법을 이용한 아시아 항만의 경쟁력 수준 분류와 부산항의 위상)

  • 류형근;이홍걸;여기태
    • Journal of Korean Society of Transportation
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    • v.21 no.5
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    • pp.7-18
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    • 2003
  • Due to the changes of shipping and logistic environment, Asian ports today face severe competition. To be a mega-hub port, Asian ports have achieved a big scale development. For these reasons, it has been widely recognized as an important study to analyze and evaluate characteristics of Asian ports, from the standpoint of Korea where Busan Port is located. Although some previous studies have been reported, most of them have been beyond the scope of Asian ports and analyzed the world's major ports; moreover, the studied ports have been about the ports which are well known from the previous research and reports. So, most studies is unlikely to be used as substantial indicators from the perspective of Busan Port. In addition. most of the existing studies have used hierarchical evaluation algorithm for port ranking, such as AHP (analytical hierarchy process) and clustering analysis. However, these two methods have fundamental weaknesses from the algorithm perspective. The aim of this study is to classify major Asian ports based on competitiveness level. Especially. in order to overcome serious problem of the existing studies, major Asian ports were analyzed by using objective indicators. and Fuzzy C-Means algorithm, which alleviates the weakness of the clustering method. It was found that 10 ports of 16 major Asian ports have their own phases and were classified into 4 port groups. This result implies that some ports have higher potential as ports to lead some zones in Asia. Based on those results. present status and future direction of Busan port were discussed as well.