• Title/Summary/Keyword: Case Study Approach

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Large-scale Culture of Plant Cell and Tissue by Bioreactor System

  • Son, Sung-Ho;Park, Sung-Mee;Park, Seung -Yun;Kwon, Oh-Woung;Lee, Yun-Hee;Paek, Kee-Yoeup
    • Journal of Plant Biotechnology
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    • v.1 no.1
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    • pp.1-7
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    • 1999
  • Large-scale cultures of plant cell, tissue, and organ have been achieved by using BTBB. When different sized BTBBs (5 L, 20 L, 100 L, 300 L, and 500 L) were tested for the culture of yew cells (Taxus cuspidata Sieb. et Zucc.), cell growth increment reached to 94.5% in SCV after 24 days of culture with 30% of inoculation cell density. However, there were some variations in the production of taxol and its derivatives among the BTBBs of different size. Approximate 4 ㎎/l of taxol and 84 ㎎/l of total taxanes were obtained by using a 500L BTBB after 6 weeks of culture. With a 20L BTBB, about 20,000 cuttings of virus-free potatoes (cv. Dejima) could be obtained by inoculating 128 explants and maintaining 8 weeks under 16 hr light illumination. The frequency of ex vitro rooting of the cuttings revealed as more than 99% under 30% shade. By incorporating two-stage culture process consisting of multiple bulblet formation in solid medium and bulblet development in liquid medium, mass propagation of lily through bioreactor seemed to be possible. In the case of 'Marcopolo', the growth of mini-bulblets in BTBB was nearly 10 folds faster than that of the solid medium. Time course study revealed that maximum MAR yield of ginseng (Panax ginseng C. A. Meyer) in a 5 L and 20 L BTBB after 8 weeks of culture was 500 g and 2.2 ㎏, respectively. By cutting the MAR once and/or twice during the culture, the yield of root biomass could be increased more than 50% in fresh weight at the time of harvest. With initial inoculum of 500 g of sliced MAR in a 500 L BTBB, 74.8 ㎏ of adventitious root mass was obtained after 8 weeks of culture. The average content of total ginseng saponin obtained from small-scale and/or pilotscale BTBBs was approximately 1% per gram dry weight. Based on our results, we suggest that large-scale cultures of plant cell, tissue, and organ using BTBB system should be quite a feasible approach when compared with conventional method of tissue culture.

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A Systematic Approach to Decide Maximum Berthing Ship Size Coupled with Berth Design Criteria - A Case of Port of Ulsan - (부두 설계기준을 고려한 접안가능 최대선형의 결정에 관한 연구 - 울산항을 중심으로 -)

  • Jun, Sang-Yup;Kim, Young-Mo;Woo, Byung-Goo;Chung, Hyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.14 no.1
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    • pp.45-54
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    • 2008
  • "Summer Deadweight Tonnage(SDWT)" is used as the criteria of the berthing capacity when establishing port entry limits under current guideline. The important factors affecting to the maximum ship size of possible berthing are mass, length and breath of the ship rather than deadweight. Therefore this guideline should be modified to ensure safety and efficient operation of berth. This study aimed to propose a rational guideline to adjust the berthing capacity. In order to decide proper berthing capacity, three berths of Port of Ulsan were selected and systematic evaluations for the safety of passage transit, berthing maneuvers, ship motions at berth and stabilities of structures were conducted. Small changes of ship size had little effect on those characteristics and little significant differences were found according to the increase of ship size at the same displacement. The evaluation results of the increasement of 50% of berthing capacity at 20,000 DWT, 25% at 40,000 DWT and 13% at 150,000 DWT were within the design criteria in which the berths were built. Therefore, if the channel width, diameter of turning circle, berth length and mooring arrangements are satisfied with the criteria, the current berth limitations should be adjusted by the displacement. as substitute for the deadweight.

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Issues on User Participation in Korean Disability Services : Implications from UK Community Care (영국 커뮤니티케어의 이용자 참여 기제와 한국 장애인복지서비스에 대한 함의)

  • Kim, Yong-Deug
    • Korean Journal of Social Welfare
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    • v.57 no.3
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    • pp.363-387
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    • 2005
  • The purpose of this study is to find out implications which can be useful for enhancement of user participation in Korean disability services from UK community care experience. In Korea, until recently dominant issue on social services always has been the shortage of service provision. But during the recent 20 years, we experienced great expansion in quantity, as though it may be not yet enough. And more recently, disabled people and organizations began to actively argue for appropriate service in quantity and quality. Now, Korean disability policy and practice are confronted to the difficult and embarrassing task how to meet the need of disabled people with limited resources, and how to response to the disabled people's voice arguing on independence and choice. This task would require somewhat deliberate reform which might be quite different from previous one. UK's experience of implementation and development of community care system would give meaningful implications to Korean disability service policy and practice related to user participation. The results of the review on user participation issues in the UK community care give several implications to Korean disability services. Above all, consumerist approach which is the key strategy adopted by UK community care change is not appropriate for Korean disability service because of largely different service environment. The second implication is about decentralization. To enable decentralization of social service leads to enhancement of user involvement avoiding a lowering of service quality, prerequisite conditions should be secured. A third is securing and making declaration on the disabled person's right to assessment and constructing public service system operated by case management process. Fourth, formalized complaints procedure should be established. Fifth, professional education which enables professionals to encourage participation of disabled people should be developed, and the role of disability movement leading disabled users to participate on their services also should be highlighted.

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Bayesian quantile regression analysis of private education expenses for high scool students in Korea (일반계 고등학생 사교육비 지출에 대한 베이지안 분위회귀모형 분석)

  • Oh, Hyun Sook
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.6
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    • pp.1457-1469
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    • 2017
  • Private education expenses is one of the key issues in Korea and there have been many discussions about it. Academically, most of previous researches for private education expenses have used multiple regression linear model based on ordinary least squares (OLS) method. However, if the data do not satisfy the basic assumptions of the OLS method such as the normality and homoscedasticity, there is a problem with the reliability of estimations of parameters. In this case, quantile regression model is preferred to OLS model since it does not depend on the assumptions of nonnormality and heteroscedasticity for the data. In the present study, the data from a survey on private education expenses, conducted by Statistics Korea in 2015 has been analyzed for investigation of the impacting factors for private education expenses. Since the data do not satisfy the OLS assumptions, quantile regression model has been employed in Bayesian approach by using gibbs sampling method. The analysis results show that the gender of the student, parent's age, and the time and cost of participating after school are not significant. Household income is positively significant in proportion to the same size for all levels (quantiles) of private education expenses. Spending on private education in Seoul is higher than other regions and the regional difference grows as private education expenditure increases. Total time for private education and student's achievement have positive effect on the lower quantiles than the higher quantiles. Education level of father is positively significant for midium-high quantiles only, but education level of mother is for all but low quantiles. Participating after school is positively significant for the lower quantiles but EBS textbook cost is positively significant for the higher quantiles.

Stability Analysis and Design of the Pretension Soil Nailing System (프리텐션 쏘일네일링 시스템의 안정해석 및 설계)

  • Park Si-Sam;Kim Hong-Taek;Choi Young-Geun
    • Journal of the Korean Geotechnical Society
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    • v.20 no.7
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    • pp.197-206
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    • 2004
  • The ground anchor support system may not be occasionally used because of space limitations in urban excavation sites nearby the existing structures. In this case, soil nailing system with relatively short length of nails could be efficiently adopted as an alternative method. The general soil nailing support system, however, may result in excessive deformations particularly in an excavation zone of the existing weak subsoils. Pretensioning the soil nails then could play important roles to reduce deformations mainly in the upper part of the nailed-soil excavation system as well as to improve local stability. In this study, a newly modified soil nailing technology named as the PSN (Pretension Soil Nailing), is developed to reduce both facing displacements and ground surface settlements in top-down excavation process as well as to increase the global stability. Up to now, the analytical procedure and design technique are proposed to evaluate maximum pretension force and stability of the PSN system. Also, proposed are techniques to determine the required thickness of a shotcrete facing and to estimate probability of a failure against the punching shear, Based on the proposed procedure and technique, effects of the radius of a influence circle and dilatancy angle on the thickness of a shotcrete facing, bonded length and safety factors are analyzed. In addition, effects of the reduction of deformations expected by pretension of the soil nails are examined in detail throughout an illustrative example and the $FLAC^{2D}$ program analysis. And a numerical approach is proposed PSN system using the shear strength reduction technique with the $FLAC^{2D}$ program.

Usefulness of Tunneled Trans-saphenous IVC Catheters for Long Term Venous Access in Pediatric Patients (소아환자에서 대복재정맥을 통한 하대정맥도관법의 유용성)

  • Kim, Seung-Hwan;Kim, Seong-Min;Oh, Jung-Tak;Han, Seok-Joo;Choi, Seung-Hoon
    • Advances in pediatric surgery
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    • v.12 no.2
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    • pp.167-174
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    • 2006
  • Central venous catheter (CVC) for long-term venous access is indispensable for various reasons including hyperalimentation, frequent blood sampling, frequent IV drug use in pediatric patients. We report clinical experience of surgical neonates in whom CVC was inserted primarily via great saphenous vein into suprarenal inferior vena cava. From March 2004 to March 2006, we performed CVC insertion via saphenous vein - contralateral side to main wound - into suprarenal inferior vena cava in surgeries of neonates. 2.7Fr or 4.2Fr, single lumen, tunneled Broviac catheters (Bard Access system, Inc, Salt Lake City, Utah) were used. Skin exit site of tunneled catheter was located in ipsilateral flank area just below edge lower rib. At the end of the procedure, location of the catheter tip was confirmed by plain radiography of abdomen. We retrospectively reviewed the admission records of the patients including nursing staff charts. Nine (50.0 %) patients were male and nine (50.0%) were female. Median gestational age was 38 weeks (range, 29-42 weeks) and median birth weight was 3,105 gm (range, 1,040-3,720 gm). Median age at catheter insertion was 38.5 days (range, 1-236 days). The purpose of CVC insertion was short-and long-term hyperalimentation in nine (50.0 %) patients. CVC insertion was performed in operation room under general anesthesia in sixteen (88.9 %) patients (in these cases, CVC insertion was performed just prior to concurrent operation) and neonatal intensive care unit (NICU) under local anesthesia with adequate sedation in two (11.2%). During the admission period (total catheter-indwelling time: 553 days), CVC functioned well without any significant side effects. Transient swelling of the ipsilateral leg (n=1, 5.6 %) and transient migration of catheter tip (n=1, 5.6 %) were noted, which did not affect function of the indwelled CVC. Mean catheter-indwelling time was 30.7days (range, 3-72 days). All catheters were removed electively except two mortality case. Complications, such as thrombosis, infection, kinking or extravasation of drugs, were not observed in our study period. Tunneled trans-great saphenous vein inferior vena cava catheters are not only comparable to cervical CVCs in terms of function and complication rates, but also very beneficial in selected patients, especially those in whom cervical approach is technically impossible or contraindicated.

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Sensitivity Analysis for Input Parameters of a Radiological Dose Assessment Model (U. S. NRC Model) for Ingestion Pathways (오염 음식물에 의한 피폭선량 평가모델 (U. S. NRC 모델)의 입력변수에 대한 민감도분석)

  • Hwang, Won-Tae;Suh, Kyung-Suk;Kim, Eun-Han;Choi, Young-Gil;Han, Moon-Hee
    • Journal of Radiation Protection and Research
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    • v.25 no.4
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    • pp.233-239
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    • 2000
  • The sensitivity analysis of input parameters was Performed fer an ingestion dose assessment model (U. S. NRC's Regulatory Guide 1.109 model) from routine releases of radionuclides. In this study, three kinds of typical Korean foodstuffs (rice, leaff vegetables, milk) and two kinds of radionuclides $(^{l37}Cs,\;^{131}I)$ were considered. The values of input parameters were sampled using a Latin hypercube sampling technique based on Monte Carlo approach. Sensitivity indices, which represent the influence or the importance of input parameters for predictive results, were quantitatively expressed by the partial rank correlation coefficients. As the results, the ratio of the interception fraction to the yield of agricultural plants and the human consumption rate were sensitive input parameters for the considered foodstuffs and radionuclides. Additionally, in case of milk, the transfer factor of radionuclides from animal intake to milk and the daily intake rate of feedstuffs were sensitive input parameters. The weathering removal half-life and the delay time from food production to human consumption were relatively sensitive for $^{137}Cs$ and $^{131}I$ depositions, respectively.

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Estimation of Heavy Metal Contamination Level in Masan Bay and Nakdong Estuary Sediments (마산만과 낙동강 하구역 해양 퇴적토의 중금속 오염도 산정 연구)

  • Lee, Junho;Yang, Changeun;Han, Kyongsoo;Lee, Taeyoon
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.3
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    • pp.13-21
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    • 2020
  • The purpose of this study is to evaluate the concentrations of heavy metals in the marine sediments near the Masan bay and the Nakdong estuary, and to investigate the pollution intensity levels of six heavy metals using the existing pollution intensity assessment method. According to the US environmental protection agency, in the case of Cu, the B1 area was classified as severe pollution, while in Ni and Zn, it was classified as moderate pollution in some areas. According to the classification of Igeo, EF and PERF, the A and B regions were polluted by Cd. In particular, in the B1 region, Igeo, EF, and PERF values were the highest in all regions, and were regarded as serious pollution. According to the mean PEL quotient classification, which takes into account the effects of all six heavy metals, there is a 21% probability of toxicity from heavy metals in all regions. The highest concentration of Cd in the B1 region is 1.5 mg/kg. Therefore, the contamination of Cd contained in sediment near Masan Bay is serious, so it is necessary to clarify the cause and take careful approach to future treatment.

A Study on the Problems of the Doctrine of Utmost Good Faith in English Marine Insurance Law (영국(英國) 해상보험법(海上保險法)에서 최대선의원칙(最大善意原則)의 문제점(問題點)에 관한 고찰(考察))

  • Shin, Gun-Hoon
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.14
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    • pp.103-152
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    • 2000
  • English contract law has traditionally taken the view that it is not the duty of the parties to a contract to give information voluntarily to each other. In English law, one of the principal distinctions between insurance contract law and general contract law is the existence of the doctrine of utmost good faith in insurance law. The doctrine gives rise to a variety of duties, some of which apply before formation of the contract while others apply post-formation. This article is, therefore, designed to analyse the overall structure and problems of the doctrine of utmost good faith in English marine insurance law. The results of analysis are as following : First, the requirement of utmost good faith in marine insurance law arises from the fact that many of the relevant circumstances are within the exclusive knowledge of the assured and it is impossible for the insurer to obtain the facts to make a appropriate calculation of the risk that he is asked to assume without this information. Secondly, the duty of utmost good faith provided in MIA 1906, s. 17 has the nature as a bilateral or reciprocal, overriding and absolute duty. Thirdly, the Court of Appeal in Skandia held that breach of the pre-formation duty of utmost good faith did not sound in damages since the duty did not arise out of an implied contractual term and the breach did not constitute a tort. Instead, the Court of Appeal held that the duty was an extra-contractual duty imposed by law in the form of a contingent condition precedent to the enforceability of the contract. Fourthly, the scope of the duty of utmost good faith is closely related to the test of materiality and the assured is required to disclose only material circumstances subject to MIA 1906, s. 18(1) and 20(1). The test of materiality, which had caused a great deal of debate in English courts over 30 years, was finally settled by the House of Lords in Pan Atlantic and the House of Lords rejected the 'decisive influence' test and the 'increased risk' test, and the decision of the House of Lords is thought to accept the 'mere influence' test in subsequent case by the Court of Appeal. Fifthly, the insurer is, in order to avoid contract, required to provide proof that he is induced to enter into the contract by reason of the non-disclosure or misrepresentation of the assured. Sixthly, the duty of utmost good faith is, in principle, terminated before contract is concluded, but it is undoubtful that the provision under MIA 1906, s. 17 is wide enough to include the post-formation duty. The post-formation duty is, however, based upon the terms of marine insurance contract, and the duty lies entirely outside s. 17. Finally, MIA 1906, s. 17 provides expressly for the remedy of avoidance of the contract for breach of the duty. This means rescission or retrospective avoidance of the entire contract, and the remedy is based upon a fairly crude 'all-or-nothing' approach. What is needed in English marine insurance law is to introduce a more sophiscated or proportionate remedy.

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INFERIOR ALVEOLAR NERVE INJURY FOLLOWING REMOVAL OF MANDIBULAR THIRD MOLAR AND PANORAMIC RADIOLOGICAL RISK SIGN (파노라마 방사선사진상의 위험 징후와 하악 제3 대구치 발치 후 하치조신경 손상)

  • Lee, Yong-In;Kim, Chang-Soo;Hong, Jong-Rak;Lee, Jun-Hee;Shin, Chang-Hun;Pyo, Sung-Woon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.30 no.2
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    • pp.165-171
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    • 2008
  • The aim of this study was to evaluate the incidence of panoramic radiological risk signs related with mandibular third molar extraction, and the relationship between these risk signs and inferior alveolar nerve (IAN) injury after tooth extraction. Cases were defined as 1000 mandibular third molars extracted by surgical approach at Samsung Medical Center during the period from March 2001 to December 2006. Seven radiological risk signs were assessed on the panoramic radiogram by three expert oral surgeons. Clinical demographic data and severity of IAN injury were examined on medical records. Bivariate analyses were completed to assess the relationship between radiological risk signs and IAN injury. The radiological risk signs showed in 381 cases(38.1%). The incidence of each radiological risk signs were; interruption of IAN white line, 152 cases(15.2%); deflected roots, 141 cases(14.1%); darkening root, 119 cases(11.9%); diversion of IAN, 57 cases(5.7%) ; IAN narrowing, 37 cases(3.7%); root narrowing, 17 cases(1.7%); dark and bifid apex, 10 cases(1.0%). The incidence of IAN injury in cases with risk signs were: in the case of any sign, 3.6%; interruption of IAN white line, 2.6%; deflected roots 5.7%; darkening root. 3.4%; diversion of IAN, 5.7%; IAN narrowing, 3.7%; root narrowing, 5.9%; dark and bifid apex, 0%. No IAN injury was showed in 619 cases without risk sign (p<0.05). In conclusion, the presence of panoramic risk signs was associated with an increased risk for IAN injury during mandibular third molar extraction, whereas the absence of risk signs was associated with a minimal risk of nerve injury.