• 한국산학기술학회논문지
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• 제17권9호
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• pp.265-278
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• 2016

본 연구에서는 국내에서 서식하는 외래어종인 배스와 블루길을 대상으로 소상능력 실험을 수행하였다. 실험은 대상 어류의 크기에 따라 4개 그룹으로 구분한 후 각 그룹별 4단계 유속에 대한 실험을 진행하였다. 분석방법은 유속에 따라 기준선을 통과하는 개체 수를 영상촬영을 이용해 분석하였으며 어류의 유영 및 소상 가능정도를 육안으로 관찰하였다. 또한 고유속 급류로 인해 5분 내 하류로 내려오면 기준선 통과 개체 수에서 제외하였으며 유속은 좌안, 우안, 중앙에서 측정하여 평균값을 사용하였다. 실험 결과 어종 및 개체 크기에 상관없이 유속이 빠를수록 소상하는 외래어종은 감소하는 것으로 나타났다. 어종별 비교 결과 배스의 소상능력이 블루길보다 높게 나타났으나 개체 크기를 고려하면 차이는 크지 않는 것으로 판단된다. 소상 후 급류로 인해 하류로 밀려 내려오는 경우를 제외하고 실험오차를 고려하면 외래어종이 소상 가능한 한계속도는 1.11 m/s 이상인 것으로 판단된다. 실험 결과는 고유속 흐름을 이용한 어류 차단과 외래어종의 관리를 위한 기초자료로 활용이 가능하며 향후 고유속에서 기준선을 통과하는 어류가 돌발속도에 의한 것인지 순항속도에 의한 것인지 판단하기 위해서는 지속적인 실험과 검증 및 모니터링이 필요하다. 또한 외력에 의한 반응 및 유량에 의한 압력 차이 등을 고려한 어류의 반응검토도 필요할 것으로 판단된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.413-421
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• 1997

This paper presents the comparison and evaluation of the existing test results and empirical formulas of high-strength concrete available in the literature for various types of models to describe the stress-strain relationship. The range of concrete compressive strength taken into account in this study was 400 to 1200kg/㎠ and the comprehensive assessment of each linearly varying ascending part and brittle type of descending one of each model was carried out. The results show that the fixed curve equation seems to be recommended to well describe the ascending part and so does Fafitis' exponential equation for the descending part in the stress-strain relationship of the high and ultra high-strength concrete.

• 한국연초학회지
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• 제28권1호
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• pp.58-66
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• 2006

Threshold limit value (TLV) test between expert and consumer panel was conducted about absolute, recognition and difference threshold respectively. And we tried to suggest appropriate and minimum acceptable menthol concentration level by consumer panel. Determination of threshold value was based on ASTM E 679-79 method by forced-choice ascending concentration series. In addition, a semi-ascending paired difference method was referred to conduct test. The group threshold value was determined as the value of geometric mean individual threshold. The smokers were dividend by two groups, trained and consumer panel. Trained panel was selected according to sensitivity to menthol discrimination. Consumer panel wasrecruited in proportion as population ratios including female smokers. They were all over twenty years old volunteers and summed up thirty four persons. In terms of sensor evaluation, overall difference test with seven-category scale by both trained and consumer panelists were done. On judging correct or incorrect answer, two by three cut-off levels applied to. Every test was conducted with two sessions, before smoking and during smoking period. And, only two samples served each paneI per test with regard to sensory fatigue and reliable results. All tests were replicated, and in total 32 times per panelist. In conclusion, the recognition threshold about consumer and expert panel was 358 ppm/cig. and 276 ppm/cig. in separately. Besides, absolute and difference thresholds were obtained also. And, we conduct difference threshold test with two different ways, upward and downward. And, The results of each method were 246, 195 ppm/cig., 1414, 1336 ppm/cig. and 1047, 972 ppm/cig.

• Journal of Chest Surgery
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• 제42권2호
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• pp.135-140
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• 2009

배경: 동종이형의 심장이식 후에 나타나는 만성 거부반응은 수술 후 약 6개월이 지나 나타나며, 이로 인해 이식된 심장의 관상동맥의 동맥 경화 소견과 심장의 손상을 일으키는 혈관병증이 나타나는 바, 대혈관인 대동맥에서도 이러한 소견을 보이는 지를 확인하고자 하였다. 대상 및 방법: $200{\sim}300gm$의 백서(Spraque-Dawley Rat)에서 이소성의 동종이형의 심장이식(heterotopic heart alto-transplantation)을 Ono-Lindsey method로 시행한 후 사이클로스포린(cyclosporin A 10mg/kg/day, 종근당 제공)을 투여하여 3개월 이상 생존한 군에서 동물을 희생시킨 후 자가 상행 대동맥과 이식된 심장의 대동맥에서 각각 조직 절편을 얻어 조직 검사를 시행하여 비교하였다. 자가 상행 대동맥의 조직 검사(N=9, native ascending aorta)와 동종 이형의 이식된 심장의 대동맥(N=13, alto-transplanted aorta)의 조직 검사를 동종이형의 심장이식 후의 만성 거부 반응의 특징적인 조직 검사 소견인 1) 내막 비후(intimal thickening), 2) 중층 비후(medial hyperplasia), 3) 중층 석회화(medial calcification), 4) 중층 염증(medial inflammation), 5) 연골 화생(chondroid metaplasia)에 대하여 한 명의 병리의에 의해 대조군과 이식군에서 각각 심한 정도를 통계처리(Mann-Whitney Test, SPSS version 12.0 Windows)하여 비교하였다. 결과: 중층 비후 외(p=0.36)에 내막 비후(p<0.0001), 중층 석회화(p=0.045), 중층 염증(p<0.0001), 연골 화생(p=0.045)에 있어 이식된 심장의 대동맥에서 의미 있는 변화를 보였다. 결론: 동종 이형의 심장 이식 후에 만성 거부 반응에 의한 혈관병증(cardiac allograft vasculopathy)은 관상 동맥을 침범하여 심근의 손상을 가져오며, 이와 같은 만성 거부 반응에 의한 혈관 병증의 변화는 대혈관인 이식된 대동맥에서도 상기의 결과와 같이 나타나 대동맥에서도 만성적인 거부 반응이 진행되고 있음을 확인할 수 있었다.

• The Journal of Korean Physical Therapy
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• 제14권4호
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• pp.64-74
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• 2002

The SSEP(SomatoSensory Evoke Potentials) test is a valid and repeatable technique which correlates with clinically assessed joint position & vibration sense, skin touch & pressure sense. Also SSEP study is a simple and quantitative test, and has been used to evaluate the sensoty system along the somatosensory pathway from peripheral sensory receptor to the cortex. The ascending pathway of SSEP has been know to be posterior column-lemniscal pathway, but not without controversy. There are two kind of test mathods : one of test is median nerve SSEP and other test is posterior tibial nerve SSEP. Recently, SSEP used to performed to evaluate the usefulness of dermatomal SSEP(D-SSEP) and segmental SSEP(5-SSEP) for the diagnosis of lumbasacral radiculopathy, and it can be measure of ingual ahd palatine evoked potentials & indicator of medullary function useful for the diagnosis of brain death.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.654-670
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• 2020

Workers at construction sites are easily exposed to many dangers and accidents involving falls, tripping, and missteps on stairs. However, researches on construction site monitoring system to prevent work-related injuries are still insufficient. The purpose of this study was to develop a wearable textile pressure insole sensor and examine its effectiveness in managing the real-time safety of construction workers. The sensor was designed based on the principles of parallel capacitance measurement using conductive textile and the monitoring system was developed by C# language. Three separate experiments were carried out for performance evaluation of the proposed sensor: (1) varying the distance between two capacitance plates to examine changes in capacitance charges, (2) repeatedly applying 1 N of pressure for 5,000 times to evaluate consistency, and (3) gradually increasing force by 1 N (from 1 N to 46 N) to test the linearity of the sensor value. Five subjects participated in our pilot test, which examined whether ascending and descending the stairs can be distinguished by our sensor and by weka assessment tool using k-NN algorithm. The 10-fold cross-validation method was used for analysis and the results of accuracy in identifying stair ascending and descending were 87.2% and 90.9%, respectively. By applying our sensor, the type of activity, weight-shifting patterns for balance control, and plantar pressure distribution for postural changes of the construction workers can be detected. The results of this study can be the basis for future sensor-based monitoring device development studies and fall prediction researches for construction workers.

• Restorative Dentistry and Endodontics
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• 제26권5호
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• pp.379-386
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• 2001

This study was performed to evaluate the sealing ability of various retrograde filling materials by using bacterial penetration and dye penetration test. One hundred and forty extracted human teeth with single, straight canals and mature apiece were collected and used for this study. All canals were instrumented using an engine driven Ni-Ti file (ProFile). After removing 3mm from the apex of tooth, a standardized 3mm root end cavity was prepared using an ultrasonic instrument. The 70 teeth were randomly divided into 7 groups : 6 groups for retrograde filling using Super-EBA, ZOE, Chelon-Silver, IRM, ZPC and amalgam. The 7th group was used as a negative control. Nail varnish was applied to all external root surfaces to the level of the reseated root ends to prevent lateral microleakages. The specimens were then sterilized in an ethylene oxide sterilizer for 24 hours. 2 mm of the reseated root was immersed in a culture chamber containing a Tripticase Soy Broth with a phenol red indicator. The coronal access of each specimen was inoculated every 72 hours with suspension of Proteus vulgaris. The culture media were observed every 24hours for color change indicating bacterial contamination. The specimens were observed for 4weeks. The remaining 70 teeth were submitted to a dye penetration test. The canals of all teeth were first sealed with AH26 and obturated using an Obtura II system. Root resection, root end preparation and retrograde filling was performed as above. All specimens were suspended in 2% methylene blue dye for 72 hours before being ion gitudinally split. The degree of dye penetration was then measured using a stereomicroscope at 10 magnification and evaluated. The results were as floows : 1. In the bacterial penetration, the degree of leakage was the lowest in the Super-EBA, followed by, in ascending order, ZOE, Chelon-Silver IRM and ZPC. The amalgam showed highest bacterial leakage of all(p<0.01). 2. In the dye penetration, the degree of microleakage was the lowest in the Chelon-Silver and Super-EBA, followed by, in ascending order, IRM, ZPC. The ZOE and amalgam showed the highest microleakage of all (p<0.05). These results suggested that the eugenol based cement, Super-EBA, have excellent sealing ability as a retrograde filling material.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.33-36
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• 1999

The KOMPSAT, which is scheduled to be launched by Taurus launch vehicle in late November of 1999, will be in a sun-synchronous orbit with an altitude of 685km, eccentricity of 0.001, inclination of 98deg and local time of ascending node of 10:50 a.m. Electronics and Telecommunications Research Institute and Daewoo Heavy Industry had jointly developed a KOMPSAT Simulator as a component of the KOMPSAT Mission Control Element. The MCE had been delivered to Korea Aerospace Research Institute for the KOMPSAT ground operation. It is being used for training of KOMPSAT ground station personnel. Each of satellite subsystems and space environment were mathematically modeled in the simulator. To verify the overall function of KOMPSAT simulator, a Launch and Early Orbit Phase(LEOP) operation simulations have been performed. The simulator had been verified through various tests such as functional level test, subsystem test, interface test, system test, and acceptance test. In this paper, simulation results for LEOP operations to verify flight software adapted into simulator, satellite subsystem models and environment models are presented.

• 한국생산제조학회지
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• 제22권3호
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• pp.380-387
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• 2013

In this study, two finite element (FE) models were developed to evaluate the thermal characteristics of a feeding axis of a CNC lathe. One was used for analysis of heat transfer to identify the temperature distribution of the feeding axis and then, the other was used for analysis of thermal deformation to evaluate its structural behavior based on the temperature distribution. The FE models were based on the test standard for the axial thermal displacement. The feeding velocity was composed of three steps: the ascending, constant, and descending velocities. Therefore, the heat generation and convection coefficient were calculated for each velocity and applied to the thermal FE model. The convection coefficient for the ball screw rotation was based on an experimental equation. The result of the analytical thermal displacement was compared with that of the experimental displacement to verify the finite element models.

• 대한기계학회논문집
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• 제14권2호
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• pp.399-406
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• 1990

This paper is studied to know corrosive wear mechanism of STS304 steel on atmospherical temperature against mating material as the same. The corrosive test was carried out by rubbing the annular surface of two test pieces in distilled water and NaCl aqueous solution. The corrosive wear mechanism was investigated by S.E.M. The experimental results show that there is one Lcr transferring from severe wear to mild wear on change of NaCl concentration and atmospherical temperature, and which is the other still remaining in server wear state. It was found that the critical sliding distance Lcr shorten with increasing NaCl concentration but it is longer with ascending atmospherical temperature and the mild wear state still continues under the condition of high generation rate and elimination rate of the corrosive product. Considering upon the result, the model of corrosive wear mechanism is proposed.