• Title/Summary/Keyword: 장기 안정성

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An Empirical Study on the Structural Relationships among Perceived Service Quality, Customer Satisfaction and Relationship Quality in Liner Shipping Companies - Focused on Freight Forwarder - (정기선사에 대한 지각된 서비스품질, 고객만족 및 관계질간의 구조적 관계에 관한 실증연구 - 운송주선인을 중심으로 -)

  • Choi, Young-Ro
    • Journal of Korea Port Economic Association
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    • v.26 no.4
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    • pp.147-167
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    • 2010
  • The purpose of this study is to analyze the components and verify the relationship among service quality, customer satisfaction and relationship quality in liner shipping company. In order to achieve the purpose of this study, literature survey related to service quality, customer satisfaction, relationship quality was carried out and took an empirical analysis by the use of questionnaire method for employees in international freight forwarders. The final results are as follows; First, correlations between service quality and customer satisfaction are found to be positive. But service quality component of tangibles and responsiveness with customer satisfaction are not to be positive. Second, as the other study on the similar logistics industries, the correlation between customer satisfaction and relationship quality is found to be positive in this study.

Quality Evaluation of Long-Term Shipboard Salinity Data Obtained by NIFS (국립수산과학원 장기 정선 관측 염분 자료의 정확성 평가)

  • PARK, JONGJIN
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.26 no.1
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    • pp.49-61
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    • 2021
  • The repeated shipboard measurements that have been conducted by the National Institute of Fisheries Science (NIFS) for more than a half century, provide the valuable long-term hydrographic data with high spatial-temporal resolution. However, this unprecedent dataset has been rarely used for oceanic climate sciences because of its reliability issue. In this study, temporal variability of salinity error in the NIFS data was quantified by means of extremely small variability of salinity in the deep layer of the south-western East Sea, in order to contribute to studies on long-term variability of the East Sea. The NIFS salinity errors estimated on the isothermal surfaces of 1℃ have a remarkable temporal variation, such as ~0.160 g/kg in the year of 1961~1980, ~0.060 g/kg in 1981~1994,~0.020 g/kg in 1995~2002, and ~0.010 g/kg in 2003~2014 on average, which basically represent bias error. In the recent years, even though the quality of salinity has been improved, there still remain relatively large bias errors in salinity data presumably due to failure of salinity sensor managements, especially in 2011, 2013, and 2014. On the contrary, the salinity in the year of 2012 was very accurate and stable, whose error was estimated as about 0.001 g/kg comparable to the salinity sensor accuracy. Thus, as long as developing proper data quality control procedures and sensor management systems, I expect that the NIFS shipboard hydrographic data could have good enough quality to support various studies on ocean response to climate variabilities. Additionally, a few points to improve the current NIFS shipboard measurements were suggested in the discussion section.

THE EFFICACY AND SAFETY OF RISPERIDONE IN CHILD & ADOLESCENT PSYCHIATRIC INPATIENT (소아 청소년 정신과 입원 환자에서 Risperidone의 효과 및 안정성에 관한 연구)

  • Park Jeong-Hyun;Kim Boong-Nyun
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.16 no.2
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    • pp.239-250
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    • 2005
  • Objective : The purpose of this study was obtaining data on the efficacy and safety of risperidone in child and adolescent psychiatric patients. Method : Thirty one children and adolescents (males n=18, females n=13, age ranged from 5.4 to 17.3 years) treated with risperidone were selected among child and adolescent psychiatric inpatients of Seoul National University Hospital from January, 2001 to June, 2002, and charts for them were reviewed retrospectively. Results : The primary psychiatric disorders treated with risperidone were schizophrenia and other psychosis, bipolar I disorder with psychotic features, Tourette's disorder, autism spectrum disorders, mixed receptive and expressive language disorder, attention deficit-hyperactivity disorder, conduct disorder and obsessive-compulsive disorder. twelve of these had comorbid mental retardation. Primary target symptoms of risperidone were psychotic symptoms (n=13 or $41.9\%$), behavioral symptoms (n=10 or $32.3\%$) including aggression, impulsivity, hyperactivity, stereotypy nonresponsive to other psychiatric treatments, and chronic and severe tics (n=8, $25.8\%$). The efficacy of risperidone was measured by clinical global improvement (CGI) for target symptoms, $67.7\%$ of subjects showed moderate or marked improvements and its therapeutic effect appeared to be maintained during at least 7.5 months. Mean daily dosage of risperidone was $0.05{\pm}0.01mg/kg$, the group with psychotic symptoms had significantly higher mean daily dosage (0.07mg/kg) compared with other two groups (0.04mg/kg) with behavioral symptoms or tics. A variety of adverse events were reported in this study : weight gain (n=23) most commonly reported, extrapyramidal symptoms (n=15), autonomic symptoms (n=6), sedation (n=5) and symptoms related to hyperprolactinemia (n=2) etc. Although there was no drug change related to the adverse events of risperidone, and $90\%$ of subjects at their last visits were maintained on it, thus its tolerability appeared good. Conclusions Results suggest that risperidone may be relatively safe and effective drug in managing a wide variety of child and adolescent psychopathologies such as psychotic symptoms, behavioral symptoms including aggression, impulsivity, hyperactivity and stereotypy nonresponsive to other psychiatric treatments, and chronic and severe tics. Controlled and long-term studies of efficacy and safety of risperidone treatment for children and adolescents are recommended in the future.

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EVA Sheet and Butyl Rubber based Waterproofing·Anti-Corrosion Sheet for Corrosion Maintenance and Repairing in the Interior Side of the Large Steel Pipes in Water Treatment Facilities (상수도용 대구경 녹 발생 강관 내부의 보수 및 성능 유지를 위한 EVA 시트와 부틸고무를 합지한 자착식 방수방식 시트의 부착성능 평가)

  • An, Ki-Won;Kim, Byoung-Il;Oh, Sang-Keun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.3
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    • pp.267-274
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    • 2017
  • This study discusses the applicability of environmental friendly EVA based butyl rubber self-adhesive waterproof sheet designed to prevent corrosion of large scale pipes used in the water treatment facilities during th water treatment process. The experiments conducted tested the waterproofing sheet's adhesion strength on the steel surface of the pipes and checked for whether the material has the proper response properties against the various environmental conditions. In addition, it the sheet adhered to the steel pipe was to see if the adhesion hold against the water pressure due to the ingress of inflow water. Finally, the waterproofing sheet's adhesion strength was tested on a rusted steel surface to confirm whether the material has the necessary properties to secure stable adhesion strength and prevent corrosion of steel pipes at the same time during the process of installation or maintenance. As a result, the self-adhesive waterproof sheets showed that all attachments in the untreated, long term pressuring, immersion in chemical substance (hydrochloric acid, hypochlorous acid, sodium hydroxide), low temperature ($-20^{\circ}C$) conditions showed a adhesion performance of higher than 1.5N/mm, which is the performance standard of KS F 4934. Also, in the testing to check for the adhesion property against inverse water pressure, it was observed that the adhesion failure did not occur even up to $3.0N/mm^2$ pressure. Also, in the process of assessing the adhesion performance on rusted steel surface, specimens after 12 hours of corrosion treatment was shown to have 2.1N/mm, and specimens after 168 hours of corrosion treatment was shown to have 2.0N/mm adhesion strength performance.

Study of 188Re(V)-DMSA for Treatment of Cancer: Radiolabeling and Biodistribution (암 치료를 위한 188Re(V)-DMSA에 관한 연구: 방사성동위원소 표지와 생체내 분포)

  • Kim, Young Ju;Jeong, Jae Min;Chang, Young Soo;Lee, Dong Soo;Chung, June-Key;Lee, Myung Chul;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.1
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    • pp.81-88
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    • 1998
  • The purpose of this study was to examine the radiolabeling and biodistribution of $^{188}Re(V)$-DMSA as a therapeutic cancer radiopharmaceutical. We made a DMSA kit($NaHCO_3$ 1.5 mg, meso-2,3-dimercaptosuccinic acid 1.0 mg, L(+)-ascorbic acid 0.7 mg, $SnCl_2{\cdot}2H_2O$ 0.34 mg, pH 2.9) for labeling with $^{188}Re$. In this kit, $^{188}ReO_4{^-}$ 5 mCi/2 ml added and boiled at $100^{\circ}C$ for 3 hr in water bath. The final pH adjusted to 7.5 with 7% $NaHCO_3$ solution. We checked the labelling efficacy with TLC-SG(n-butanol : acetic acid : $H_2O$ = 3 : 2 : 3) and examined the stability both in room temperature and in serum at $37^{\circ}C$. Biodistribution(1, 3, 13, 24, 48 hr) of $^{188}Re(V)$-DMSA compound was evaluated in Sarcoma 180 tumor-bearing mice. Each labeling efficiency and stability at room temperature for 48 hours was over 98% and 95%, respectively. The stability in serum were 82%(6 hr) and 85%(48 hr). Tumor uptake of $^{188}Re(V)$-DMSA in Sarcoma 180-bearing mice were $0.66{\pm}0.15%$(1 hr), $0.51{\pm}0.10%$(3 hr), $0.19{\pm}0.05%$(24 hr) and $0.13{\pm}0.02%$(48 hr). These result are consistent with those of $^{99m}Tc(V)$-DMSA which were reported previously. In conclusion, $^{188}Re(V)$-DMSA may be a useful therapeutic radiopharmaceutical for treating some cancers and metastatic bone lesion.

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Durability Assessment of Geogrids by Reduction Factors (감소인자에 의한 지오그리드의 내구성 평가)

  • Jeon, Han Yong;Heo, Dai Young
    • Journal of the Korean Geosynthetics Society
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    • v.3 no.2
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    • pp.31-38
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    • 2004
  • Long-term stability of two type geogrids were evaluated. Membrane drawn type geogrid showed the exponential type tensile property and textile type geogrid showed the rapid increase of tensile property closer toward the break point. Accelerated creep test was done for textile type geogrid but not done for membrane drawn type geogrid because of its thermal property. Creep strain for membrane drawn type geogrid was larger than the ultimate tensile strain by tensile test and reduction factor by creep deformation of textile type geogrid was smaller than that of membrane type geogrid.

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The Hydraulical Monitoring of Osancheon River Environment Improvement Works (오산천 하천환경 정비사업의 수리학적 모니터링)

  • Kim, Seo-Jun;Kim, Ji-Hye;Hong, Sang-Jin;Yoon, Byung-Man
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.1875-1878
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    • 2009
  • 최근 하천의 치수, 이수적인 기능뿐만 아니라 자연 친화적인 하천을 조성하려는 노력들을 많이 하고 있다. 하지만 복원사업을 위한 설계 및 평가 기준이 명확히 정립되지 못하여 치수안전성 및 하도안정성에 대한 평가가 이루어지지 못하고 있다. 따라서 복원 기법에 대한 복원 전, 중, 후의 모니터링을 통하여 복원 후의 하천 변화를 예측하고, 실제 사업 시행 후 장기간의 모니터링을 통해서 적용 기법이 안정화 되어가는지에 대한 평가가 반드시 필요하다. 이에 본 연구에서는 2001년에 시작하여 2006년 12월에 복원 사업이 완료된 오산천 하천환경 정비사업에 대한 수리학적 모니터링을 수행하여 복원 후에 대한 하천 변화를 살펴보았다. 오산천의 경우 정비사업에 따른 공사 전, 중, 후에 대한 모니터링이 과거에 수행되었지만 단기간의 모니터링이었기 때문에 하천의 안정화 과정을 확인하기에는 많이 부족하였다. 따라서 본 연구에서는 과거 모니터링 자료를 기초로 하여 하천복원의 목적에 부합하도록 하천이 적응관리 되고 있는지 여부를 확인하기 위해 수리학적 모니터링을 하였다. 수리학 적 모니터링은 과거 수리 수문 자료를 바탕으로 호안 변화에 따른 하상 및 하도 변화와 하천 구조물의 영향분석에 초점을 맞추어 수행하였다. 본 연구에서 검토된 사항을 바탕으로 향후 하천의 수리학적 모니터링을 위한 지표 마련에 도움이 될 것으로 기대된다.

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The Study for Manufacturing Technology of Industrial Fuel from Mixed Waste Plastics (혼합폐플라스틱으로부터의 대체연료유 생산기술에 대한 실증연구)

  • Lee, Dae-Sik;Lee, Gwang-Sik;Kim, Seong-Ok;O, Se-Cheon;Kim, Su-Ryong;Gwon, U-Taek
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.11a
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    • pp.405-413
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    • 2005
  • 본 연구에서는 3톤/일의 플라스틱 투입량을 기준으로 혼합폐플라스틱으로부터 대체연료유를 생산할 수 있는 소용량 중심의 폐플라스틱 유화설비를 설계 제작하였으며 장기간에 걸친 시운전을 통하여 유화설비의 운전성 평가에 대한 실증연구를 수행하였다. 대상 폐플라스틱으로는 플라스틱 재활용 업체에서 분리 선별된 폴리에틸렌과 폴리프로필렌 그리고 이들을 혼합한 폐플라스틱을 각각 적용하였으며 $400\sim420^{\circ}C$의 분해 운전온도에서 폐플라스틱의 종류에 따른 시운전 평가를 하였다. 본 실증연구로부터 폴리에틸렌의 경우에 있어서는 79%의 재생유 회수율을 그리고 폴리프로필렌의 경우에 있어서는 80%의 재생유 회수율을 각각 얻을 수 있었으며 플라스틱 종류별 안정적인 운전조건을 확보할 수 있었다. 또한 폐플라스틱 투입량에 대한 설계용량과 운전용량과의 비교로부터 약 40$\sim$50%의 설계오차가 발생한 것으로 평가되었으며 이는 유화설비의 설계를 위하여 사용된 혼합폐플라스틱의 부정확한 물성 값에 기인한 것으로 판단된다. 따라서 본 연구로부터 얻은 시운전결과를 바탕으로 설계인자들을 확립하는 과정이 반드시 필요할 것으로 판단된다.

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A Study on AC Loss in the Two-parallel Solenoid Coil using Multi-stacked conductors (적층형 도체를 이용한 2병렬 솔레노이드 코일의 교류손실 연구)

  • Hwang, Young-Jin;Choi, Suk-Jin;Chang, Ki-Sung;Ko, Tae-Kuk
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.820_821
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    • 2009
  • 전력기기는 일반적으로 상용주파수인 60 Hz의 교류 전원하에서 운용된다. 따라서 고온초전도체를 전력기기에 응용하는데 있어 교류전류나 교류자장에 의한 교류손실 발생 문제는 전력기기의 경제적 운용과 관련하여 중요하게 부각되어 왔다. 또한 고온초전도체에서 발생하는 교류손실은 에너지의 열적 변환으로 인한 냉동부하 문제와도 관련되어 있기 때문에 전력기기의 안정적인 운용을 위해서도 반드시 연구되어야 할 부분이다. 특히 변압기와 같이 유도형 권선이 필요한 전력기기의 경우에는 무유도 권선 형태가 적용되는 다른 전력기기에 비해 교류 손실의 크기가 매우 크기 때문에 이를 줄이기 위한 방안에 대한 연구가 다각도로 이루어지고 있다. 본 연구에서는 임계전류와 인덕턴스의 크기는 동일하지만 권선 형태를 다르게 할 수 있는 유도형 솔레노이드 코일을 제작하였다. 그리고 제작된 솔레노이드 코일의 병렬연결 구조를 달리하여 각각의 구조에 대한 교류손실의 차이를 측정하고 분석하였다. 그리하여 측정된 결과를 토대로 고온초전도 선재를 이용한 솔레노이드 코일에서 교류손실을 줄이기 위한 구조적 방안을 제시하고자 한다.

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A Study of Methodology for Smart Grid Deployment (스마트 그리드 전개 방법론 연구)

  • Yang, Il-Kwon;Jung, Nam-Joon;Song, Jae-Ju;Park, Sang-Ho
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.161_162
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    • 2009
  • 'The Energy Independence and Security Act of 2007' 연방 법안이 2007년 12월 미국 의회 통과에 힘입어, 법안의 Title XIII에 포함된 '스마트그리드(Smart Grid)'는 다양한 연구 결과를 목표로 추진되고 있다. 스마트그리드는 IT를 기존 전력기술에 적용해 송전, 배전망을 지능형으로 만들자는 개념으로, 2003년 DOE가 발표한 2030년까지의 전력인프라 발전 계획인 '그리드2030(Grid2030)'의 실천 전략으로 볼 수도 있으며, 2008년부터 2020년까지 스마트그리드에 대한 연구개발, 시범사업 등을 국가 정책사업으로 추진한다는 내용을 담고 있다.[1] 이러한 장기간의 국책 사업들은 단기적으로 다양한 시범사업을 통하여 가상의 시뮬레이션이나 데모시스템 구현을 실시하여 교훈을 얻는 방식으로 진행된다. 시범 사업의 결과만으로는 유틸리티 전체의 전력망에 적용하는 것은 비용적인 측면에서나 안정적 전력 운영에 있어서 무리이기 때문에 연구 결과를 현재의 전력망과 조화롭게 점진적으로 배치시키는 과정과 상호 운용성 통합 과정이 필수적으로 따르게 된다. 본 논문에서는 스마트그리드 관련 국외 시범사업 및 관련 활동들을 살펴보고 IntelliGrid 프로그램에서 제시하는 자동화 아키텍쳐의 지능화시스템을 적용하기위한 현장 전개 방법을 고찰하고자 한다.

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