• PNF and Movement
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• 제16권2호
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• pp.287-294
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• 2018

Purpose: The neurodynamic test used to implicate symptoms arising from the nerve is proposed to selectively increase the strain of the nerve without increasing the strain of adjacent tissue, although this has not yet been established in the time of nerve tension application. This study aimed to investigate the acute effects of nerve stretching time on nerve excitability using compound nerve action potential (CNAP) analysis. Methods: Thirty healthy young adults (mean age=23.10 years) with no medical history of neurological or musculoskeletal disorder voluntarily participated in this study. Nerve excitability was assessed using the median nerve conduction velocity test. The amplitude of the CNAP was measured under three conditions: resting phase (supra-maximal stimulus, without nerve stretching), baseline phase (two-thirds of the supra-maximal stimulus, without nerve stretching), and stretch phase (two-thirds of the supra-maximal stimulus, with 1-5 minutes nerve stretching). One-way repeated measures ANOVA was conducted to compare the latency and amplitude of CNAP. A post-hoc test was analyzed using the contrast test. Results: The latency was significantly delayed after 1 min. of nerve stretching in comparison with the baseline test. However, no significant difference was found during the nerve stretching (1-5 min.). The amplitude was significantly increased by nerve stretching. Conclusion: Nerve stretching can induce nerve excitability without any nerve injury. Based on the results, more than 1 min. of nerve stretching as a neurodynamic test can be a useful method in the clinical setting.

• 한국수소및신에너지학회논문집
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• 제28권1호
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• pp.56-62
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• 2017

Although most electricity production contributes to air pollution, the vehicle organizations and environmental agency categorizes all EVs as zero-emission vehicles because they produce no direct exhaust or emissions. Currently available EVs have a shorter range per charge than most conventional vehicles have per tank of gas. EVs manufacturers typically target a range of 160 km over on a fully charged battery. The energy efficiency and driving range of EVs varies substantially based on driving conditions and driving habits. Extreme outside temperatures tend to reduce range, because more energy must be used to heat or cool the cabin. High driving speeds reduce range because of the energy required to overcome increased drag. Compared with gradual acceleration, rapid acceleration reduces range. Additional devices significant inclines also reduces range. Based on these driving modes and climate conditions, this paper discusses the performance characteristics of EVs on energy efficiency and driving range. Test vehicles were divided by low / high-speed EVs. The difference of test vehicles are on the vehicle speed and size. Low-speed EVs is a denomination for battery EVs that are legally limited to roads with posted speed limits as high as 72 km/h depending on the particular laws, usually are built to have a top speed of 60 km/h, and have a maximum loaded weight of 1,400 kg. Each vehicle test was performed according to the driving modes and test temperature ($-25^{\circ}C{\sim}35^{\circ}C$). It has a great influence on fuel efficiency amd driving distance according to test temperature conditions.

• 대한한의학원전학회지
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• 제31권1호
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• pp.57-78
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• 2018

Objectives : The paper uses recitation test, one of the study and evaluation methods in the Korean Medical Classics, to provide a basis upon which thoughts can be given to the education of Korean Medicine, and furthermore the essence of education itself. Methods : 1. The paper reviewed how recitation tests were performed in Goryeo and Joseon. 2. The paper introduces the methods of applying recitation test to the education of the Korean Medical Classics and their results. The paper furthermore discussed possible improvements. 3. The paper pondered on the traditional aspects of the significances (principles) of recitation tests and their cognitive neuroscience aspects. Results : 1. The imperial examinations for medical officers during Goryeo and Joseon both performed recitation tests, and the subject of these tests were given more weight than other subjects. 2. Recitation test is a form of education that revolves around the learners. It requires a detailed plan of execution for it to be effective. 3. The significances (principles) of recitation test are reviewed from the aspect of cognitive neuroscience, and the deductions from the traditional aspects are made into "conceptual abstract, come to things & run out knowledge, and flash back." Conclusions : Recitation test was the humanity's way of conserving and conveying knowledge & wisdom from the times before the invention of letters. This method is the oldest education method of acquiring concepts that are generalized and made abstract through indirect experiences. This method is still effective today. In the education of the Korean Medical Classics, this method was used to supplement the public education method and create an education method that revolves around individual learner in a way that utilizes the strengths of education in apprenticeship.

• 한국물환경학회지
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• 제20권1호
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• pp.48-54
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• 2004

Two methods, a Ceriodaphnia algal uptake suppression test (CAUST) and a new toxicity test based on temperature control (TTBTC) which are based on feeding behaviour and temperature control, respectively, were developed and compared for the adoption as the better methodology for short-term toxicity screening. As previously published by Lee et aI., (1997), the CAUST method is based on the feeding behaviour of C. dubia and requires as little as 1 hour of contact time between C. dubia neonates and toxicant. However, even though CAUST requires only 1 hour of contact time, this method still take many hours for the preparation and measurement. Before the test starts, neonate digestive tracts were cleared by feeding yeast to the daphnids, Neonates were then exposed to toxicant, followed by addition of Scenedesmus subspiatus into the bioassay vessels. Daphnids were examined under the bright-field microscope with the presence of algae (indicated by a green colored digestive tract) or the absence of algae. Uptake indicated no toxic effect, whereas, absence of uptake indicated toxic inhibition. Unlike CAUST, the newly developed method (TTBTC) is based on just temperature control for the toxicity test of C. dubia. Initially, neonates are exposed to toxicants while the temperature of water bath containing media increased to $35.5^{\circ}C$. After 1.25 hour of contact time, the number of the daphnids, either live (no toxic effect) or dead (toxic effect), is counted without the aid of any instrument. In both methods, median effective concentrations ($EC_{50}$ values) were computed based on the results over a range of dosed toxicant concentrations. It showed that TTBTC was as sensitive as the standard 48-hour acute bioassay and CAUST. TTBTC and CAUST were much more sensitive than the I-hour I.Q. test and 30-minute Microtox. This study indicates that TTBTC is an easier and more rapid toxicity test than the standard 48-hour acute bioassay and even CAUST.

• Journal of Positioning, Navigation, and Timing
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• 제7권3호
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• pp.127-138
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• 2018

Spoofing attacks including meaconing can provide a bogus position to a victim GPS receiver, and those attacks are notably difficult to detect at the point of view on the receiver. Several countermeasure techniques have been studied to detect, classify, and cancel the spoofing signals. Based on the countermeasure techniques, we have developed an anti-spoofing equipment that detects and mitigates or eliminates the spoofing signal based on raw measurements. Although many anti-spoofing techniques have been studied in the literatures, the evaluation test system is not deeply studied to evaluate the anti-spoofing equipment, which includes detection, mitigation, and elimination of spoofing signals. Each study only has a specific test method to verify its anti-spoofing technique. In this paper, we propose the performance evaluation test system that includes both spoofing signal injection system and its injection scenario with the constraints of stand-alone anti-spoofing techniques. The spoofing signal injection scenario is designed to drive a victim GPS receiver that moves to a designed position, where the mitigation and elimination based anti-spoofing algorithms can be successively evaluated. We evaluate the developed anti-spoofing equipment and a commercial GPS receiver using our proposed performance evaluation test system. Although the commercial one is affected by the test system and moves to the designed position, the anti-spoofing equipment mitigates and eliminates the injected spoofing signals as planned. We evaluate the performance of anti-spoofing equipment on the position error of the circular error probability, while injecting spoofing signals.

• 대한미생물학회지
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• 제21권1호
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• pp.97-106
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• 1986

Authors studies on the isolation of V. vulnificus from sea water, sea mud fishes, shellfishes and algae at the seasides of Pusan, Masan, Chungmu and Ulsan in Korea in 1985. Authors carried out test for isolated strains to bacteriological test, hemolysis test about erythrocytes of various animal, sensitivity test of various chemotherapeutic agents and serological test with antiserum of V. vulnificus. The resultls obtained were as follows: 1. V. vulnificus was isolated 15 strains from 399 total specimens: 110 cases of sea water, 40 cases of sea mud, 90 cases of fishes, 60 cases of shellfishes and 79 cases of various algae, respectively. 2. Nine strains were isolalted from sea water, 4 strains were isolated from sea mud and 2 strains were isolated from fishes, respectively. 3. Two strains among 15 strains isolated were lactose positive reaction. 4. All strains isolated were grown in concentration of $0.5%{\sim}7.0%$ NaCl, but were not grown 0% and 8.0% NaCl. 5. Hemolysis reaction about various erythrocytes was sensitived to guinea pig, human and rabbit erythrocytes, but was not sensitived to sheep erythrocytes. 6. Sensitivity test using with chemotherapeutic agents of "BioLab" Microbial Sensitivity Test Discs were generally sensitived to amikacin, ampicillin, clindamycin, erythromycin, gentamycin, kanamycin, streptomycin, tetracyclin and tobramycin, and were moderate to penicillin, but were resistant to methicillin and lincomycin, respectively. 7. The distribution of serotypes of V. vulnificus isolated were on antiserum of $0.1{\sim}07$ of V. vulnificus: 1 case of 01 and 2 cases of 07, respectively.

• 한국지반공학회논문집
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• 제34권5호
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• pp.5-17
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• 2018

본 연구에서는 풍화암에 근입된 강관 매입말뚝의 안전율 제안을 위하여 정재하시험과 동재하시험을 수행하였다. 현장재하시험은 직경이 0.508, 0.457m 인 시험말뚝을 제작하여 정재하시험(14회)과 동재하시험(EOID 14회, Restrike 14회)을 실시하였다. 이때, 재하시험은 시험말뚝 시공완료 후 (1)초기동재하시험(EOID)을 수행하였으며, (2)시공완료 28일 후 정재하시험을 시행하였으며, (3)정재하시험 완료 후 15일 후에 재항타동재하시험(Restrike)을 실시하였다. 본 연구 결과 Davisson 판정법의 동재하시험을 이용한 지지력 산정 결과 정재하시험 대비 재항타동재하시험은 약 15% 낮게 나타났다. 정재하시험과 동재하시험의 지지력 분석을 통하여 안전율을 비교하였고, 최종적으로 동재하시험 안전율을 기존 2.0에서 1.75로 수정 제안하였다.

• 한국산업보건학회지
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• 제6권2호
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• pp.176-186
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• 1996

The fit of a respirator to the face of an individual can be determined by a qualitative fit test (QLFT) or a quantitative fit test (QNFT). The pass/fail decision from a QLFT or QNFT for the same respirator on the same individual may vary from one wearing to the next, because the human facial features are complex and the respirator may not fit to the face in the same way every time it is worn. This study reports how the fit factors (FF) resulting from a QNFT on an individual vary from day to day and depend on the movements in the six fit test exercises. The reported FFs provide an objective and numerical basis (FF) which does not depend on the subject's voluntary or involuntary response. Four half-mask (H1-H4) and four full-facepiece respirators (F1-F4) were fit tested on one wearer 10 times a day for 5 days with a PortaCount (model 8010, TSI). The FFs obtained for each set of 10 fit tests on a specific day and 50 fit tests on five days involving one of the six exercise regimes have been recorded as log-normal distributions. All of the geometric standard deviations (GSD) of the overall FFs varied widely among every wearing and day except for H1 and F3, and the variability of the half-mask respirators was larger than that of the full-facepiece respirators. Among the six exercise regimes, reading or talking (RT) had markedly the lowest exercise FFs on the tested individual. Generally, there were significant differences between the first normal breathing (NB1) FFs and the remaining exercise FFs.

• 한국해양공학회지
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• 제30권4호
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• pp.268-276
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• 2016

This paper presents a study on the crashworthiness of the scaled-down stiffened panels used on a Korean icebreaker. In order to validate the crashworthiness of the panels, this paper provides various mechanical properties such as the results of a CVN test, quasi-static tensile test, and high-speed tensile test at arctic temperatures. Two types of steels (EH32 and FH32) were chosen for the material tests. CVN tests revealed that the two steels were equivalent up to −60℃ in terms of their impact energy absorption capacity. However, the toughness of FH32 was significantly superior to that of EH32. EH32 showed slightly higher flow stresses at all temperature levels compared to FH32. The improvement ratios of the yield strengths, tensile strengths, plastic hardening exponents, etc. for FH32, which were obtained from quasi-static tensile tests, showed an apparent ascending tendency with a decrease in temperature. Dynamic tensile test results were obtained for the two temperatures levels of 20℃ and −60℃ with two plastic strain rate levels of 1 s⁻¹ and 100 s⁻¹. A closed form empirical formula proposed by Choung et al. (2011;2013) was shown to be effective at predicting the flow stress increase due to a strain rate increase.

• 한국철도학회논문집
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• 제10권5호
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• pp.613-618
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• 2007

철도차량의 곡선주행성능은 유지보수관점에서 매우 중요하다. 곡선주행성능과 관련된 대차의 조향성능은 실차를 이용한 실선로 주행시험이 적전하나 차량 개발단계에서는 이를 검증하기가 용이하지 않다. 따라서 차량의 조향 특성을 효율적으로 시험하기 위한 축소 곡선트랙에 대한 연구를 수행하였다. 대차의 곡선 주행을 모사하기 위한 곡률반경 $200{\sim}250m$의 급곡선과 등가인 1/5 scale 규모의 축소 곡선트랙을 설계, 제작하였다. 1/5 scale 대차를 이용한 주행시험 시험결과 곡선 주행특성이 비교적 잘 반영되고 있음을 확인하였다.