• 한국구조물진단유지관리공학회 논문집
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• 제12권3호
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• pp.71-83
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• 2008

본 논문에서는 비접촉 손상검출기법으로 관심의 대상이 되고 있는 열화상 기법의 기본 원리, 활용 예, 제한 사항 등을 국내외 주요 연구성과를 분석하고 정리하였다. 콘크리트 구조물의 내부 결함 진단, 내부 철근 부식 측정과 콘크리트 구조물 표면과 섬유 보강 시트 사이의 비부착 검출, 포장도로의 표면 결함 검출, 오래된 건물의 표면 누수 측정, 철도 트랙 자갈의 상태 측정 등을 최근 연구결과 중심으로 광범위하게 검토하였고 최근에 보고된 실험결과도 제시하였다. 검토 결과, 열화상 기법은 광범위한 형태의 토목 구조물의 넓은 표면을 빠르게 정성적으로 검사할 수 있는 장점을 가지고 있는 것으로 확인되었다. 반면, 정량적 기법은 주변 온도 등 환경 요인에 민감하게 영향을 받는 것으로 판단되었으며, 다른 정밀계측장비와 혼용시 좋은 성과를 기대할 수 있을 것으로 예측된다.

• 한국구조물진단유지관리공학회 논문집
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• 제13권4호통권56호
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• pp.107-115
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• 2009

70~80년대에 다수의 고속도로 건설과 함께 축적된 고속도로 터널에 대한 설계 및 시공기술에 비하여 철도터널의 설계는 최근들어 활발하게 이루어지고 있는 상황이다. 따라서 고속도로 터널과 철도 터널의 비교시에는 다소간의 시간적인 차이가 있는 것이 사실이다. 본 논문에서는 서로 비슷한 굴착단면적을 갖고 있으나 단면형상에서 차이를 나타내는 고속도로 2차로 자연환기터널과 선로중심간격 4.3m의 복선철도 터널에 대해 동일한 조건하에서 지보재를 설치하지 않은 경우와 지보재를 설치한 경우에 대해 수치해석을 수행하여 단면형상 차이에 따른 터널 주변암반에 발생하는 주응력크기 및 축차응력 비교를 통한 터널의 안정성을 비교 분석하였다.

• 전기학회논문지
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• 제65권4호
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• pp.695-703
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• 2016

The maintenance method for the electrical facility of high speed railway has been evolved from inspection by personnel to the automated way by the detection devices. In particular, the signalling equipment in order to increase the safe and efficient operation of the trains is required to maintain normal operation by periodic maintenance. Because the return current gives the most important effects to the wayside equipment in case of the failures, a method is needed to measure the unbalanced rate of return current on the train at high speed driving. The Hot Box Detector(HBD) device that is installed at track-side has a function to recognize the abnormal axle box by detecting the temperature that occurs in the axle of train passing over its device. In order to implement the measurement equipment for unbalanced rate of return current and axle temperature, the design method is proposed and the experimental test results by test bed are included in the paper.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1694-1700
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• 2007

In the electrified section, both of return current and signal current are flowing in the same rail in common. But signal current shall be allowed to flow in the specific track circuit and not in the other circuit while the traction return current shall come back to power sub-station. This paper presents measuring system that use both sensor and antenna. The aim of the system is to achieve the difference in current between the two rails and the presence of trimming capacitors. In order to improve the transmission level, trimming capacitors are connected between the two rails at constant spacing. To maintain the balance of traction return current, rails of both sides may be jointed by the so-called SVPMM. The traction return current is sometimes unbalanced owing to the ill-contact of SVPMM. In this paper, we propose a diagnosis method based on a short-circuited current(Icc), trimming capacitors and traction return current measured by Korail inspection vehicles. Whether Icc is good or bad depends not only on the presence of trimming capacitors but also on the unbalance of the traction return current.

• 유통과학연구
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• 제13권8호
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• pp.27-40
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• 2015

Purpose - Total Quality Management (TQM) has received significant attention and interest from a large number of organizations around the world in various industries. These organizations have tried to embody TQM concepts in areas such as engineering and product design, marketing, R&D, procurement, production, personnel, and product inspection. Research design, data, and methodology - This study presents an overview of the fundamentals of TQM and an in depth review of the obstacles to the successful implementation of TQM. Results - In order to control the cost of manufacturing, the tracking of the cost of quality (COQ) allows companies to capture the actual overall cost incurred in producing a unit of product or service. The study explores the reasons why companies track the COQ and ways to address it. Conclusions - Based on the results, COQ is one of the key performance indicators for making more accurate strategic decisions as well as a critical aspect of TQM. The study also presents a few popular quality improvement tools that have been widely used in organizations successfully implementing TQM.

• 한국어병학회지
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• 제25권2호
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• pp.77-84
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• 2012

Various antibiotics, that could induce the appearance of resistant microorganisms, have been used for treatment or prevention of bacterial diseases in marine and ornamental fish. We determined and characterized the level of antibiotic-resistant bacteria and proportion of multi-drug resistant bacteria in intestinal microflora of both marine fish cultured in Korea and imported ornamental freshwater fish. For this the bacterial species and resistance to antibiotics were investigated in intestine of rock bream Oplegnathus fasciatus cultured in Korea and pearl gourami Trichogaster leeri imported from Singapore to characterise. Although the bacterial species were different, proportions of resistant bacteria to single antibiotics or multi-drug were higher in intestinal microflora of pearl gourami Trichogaster leeri imported from Singapore than in rock bream Oplegnathus fasciatus cultured in Korea. These results indicate that various antibiotics have been being used before trading without measures in the market of asian ornamental fishes, providing high risks for the emergence of multi-drug resistant bacteria.

• Asian Journal of Business Environment
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• 제6권2호
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• pp.27-32
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• 2016

Purpose - This paper aims to analyze and investigate to find out the appropriate ways to make an easy TBT of smart city. It is an important issue between Korea and China because TBT of smart city has lots of advantages in IT, S/W, IOT, and Home network. Research design, data and methodology - First, the paper made use of reviewing2nd data analysis and focused on group interview, and then compared with analysis on the international rule and system such as smart city system, technical regulation, and standard through test certification procedure and inspection. Second, this paper reviewed electric/electronic test, certification, and calibration. Third, through analyzing MRA between Korea and china, the paper focused on SDoC, Mutual Acceptance of International certification, and IECCB scheme. Results - Through the comparison and analysis, this paper found that it is important to promote multi-track agreements with the countries that need short-term promotion. Moreover, it is necessary to conclude an agreement with the leading countries in Middle East and Central America. Conclusions - Through the above the reviews and analysis, we can see the importance of promotion in FTA and MRA with the efforts to remove the obstacles and promote to make an easy TBT by MRA between Korea and China.

• 한국전문물리치료학회지
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• 제18권1호
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• pp.83-92
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• 2011

Osteoarthritis is a degenerative joint disease and is led to physical disability. Yet the development of effective disease-modifying treatments has lagged. In this study, I examined the effect of physical therapeutic intervention through microcurrent stimulation and attempt to find which degree of intensity, either 25 ${\mu}A$ or 500 ${\mu}A$ with a regular 5 pps pulse, is more effective in the osteoarthritis. Osteoarthritis was induced with a mixture of 2% carrageenan and 2% kaolin in 26 male Sprague-Dawley rats. The mixture (0.1 $m{\ell}$) was injected into the intra-articular capsule of knee joint once a week for three weeks. Five animals did not show degenerative changes by radiological findings and excluded in the following experiment. Osteoarthritic animals were randomly divided into 3 groups ($n_1$, $n_2$, $n_3$=7/each): untreated, treated with 25 ${\mu}A$, treated with 500 ${\mu}A$. All experimental groups received microcurrent stimulation for four weeks (15 min/day, 5 days/week). The ethological inspection of foot print analysis on the walking corridor was accomplished every week. Histological preparations and immunohistochemical staining with insulin-like growth factor-1 were also done in the articular cartilages. All of these parameters were compared with those of osteoarthritic control group (n=7). The ethological inspection of foot print analysis revealed that changes of walking track (paw width) and stride length was significantly increased in both experimental groups. The better results were observed in experimental group treated with 25 ${\mu}A$ intensity without significance than group treated with 500 ${\mu}A$. Histological preparations disclosed that routine hyaline cartilage of articular surface were altered to fibrous cartilage in untreated group and experimental group treated with 500 ${\mu}A$ intensity. But a little changes were seen in experimental group treated with 25 ${\mu}A$ intensity. Immunolocalization of insulin-like growth factor-1 was simultaneously decreased according to the duration of osteoarthritis, and did not show significant difference among the groups. In this study discovered that the microcurrent stimulation, especially 25 ${\mu}A$ intensity, had a positive effect by the ethological inspection, histological and immunohistochemical stainings. These results suggest that microcurrent stimulation with low-intensity might be effective in the promotion of healing process for the osteoarthritis.

• 한국구조물진단유지관리공학회 논문집
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• 제20권4호
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• pp.94-103
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• 2016

궤도가 역사의 상부에 위치하여 열차운행으로 인하여 발생한 진동이 직접 전달되는 선하역사에서 구조물 진동과 이로 인한 구조물기인 소음이 기준치보다 높은 것으로 나타남에 따라, 기존 선하역사에 대하여 열차 운행의 중단 없이 진동저감이 가능한 경제적, 효율적 방안이 요구된다. 이에 본 연구에서는 진동전달 경로상의 기둥에 워터젯 공법으로 기둥단면에서 피복재 부분을 파쇄한 후 진동전달 절연기능을 가지는 에폭시 소재의 방진재를 보강하여 진동을 저감시키기 위한 구조진동절연시스템을 개발하였다. 방진재의 보강체적을 변수로 한 진동절연 시스템을 실제역사 기둥의 1/4축소모형에 적용하고, 충격가진 시험을 통한 진동저감 성능과 횡하중 반복가력시험을 통한 구조적 성능을 검증하고자 하였다. 충격가진 실험결과로부터 구조진동절연시스템을 적용할 경우 고유 진동주기가 하향되어 진동응답 특성이 변화되고 감쇠비는 약 15~30%까지 증가를 나타내어 진동저감 성능이 있음을 알 수 있었다. 또한 반복하중 가력에 의한 구조성능 실험에서 하중-변위 및 강성변화에 대한 고찰과 연성도 및 에너지 소산의 증가를 보인 결과로 부터 구조부재로의 기능을 유지함을 확인 할 수 있었다.

• 한국구조물진단유지관리공학회 논문집
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• 제26권2호
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• pp.9-17
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• 2022

차세대 고속철은 주행 속도가 점점 증가하므로 이를 반영한 고속철 차량 통과교량에 대한 새로운 주행 안정성의 평가가 요구된다. 이를 위하여 현재 공용 중인 경부 고속철 구간의 대표 교량형식인 PSC (Pre-stressed Concrete) 박스거더 교량을 대상으로 관성질량을 고려한 38-자유도 차량과 궤도 불규칙성과 상호 작용력을 반영하여 모형화하였으며, 고속철 차량 주행속도 별로 동적 수치해석을 수행하여 주행 안정성을 평가하였다. 수치해석을 통해 단순교와 2 경간 연속교의 최대 수직 변위와 DAF (Dynamic Amplification Factor; 동적확대계수)를 산출하여 동적 안정성 여부를 판단하였으며, 또한 주행 속도 별 최대 수직 변위를 추정하기 위한 3차 다항 회귀 분석식을 제안하였다. 대표적인 주행 속도와 횡 단면 위치 별 수직 변위 차이를 비교하고, 종 방향 최대 면틀림을 분석하였다. 또한, 고속철 차량의 교량통과 중 교량의 수직변위에 대한 가속도 영향선과 각 항목 간의 연관성을 분석하여 주행 안정성을 평가하였다.