• 한국의류학회지
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• 제31권4호
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• pp.531-539
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• 2007

The purpose of this article was to determine how the current auto mechanic's coverall restricts movements, to develop prototype coverall, and finally, to improve working efficiency. To investigate the problem and complaint of current coveralls, 35 mechanics were interviewed. Video captured method was used to analyze the representative movement. Based on the previous investigation, the prototype coverall was developed. Pleats and band were inserted on each side of the back, under the armhole, and the back waist area for flexibility. To analyze the mobility of current and prototype coveralls objectively, range-of-motion of selected movements was measured by Leighton flexometer and goniometer. Also, wearer acceptability scale was tested to investigate subjective preference of current and prototype coveralls. As subjects, 10 auto mechanics were participated. Order of testing was randomized. ANOBA and LSD were used for statistical analysis. As a results, prototype coverall was significantly different from current coverall at all test movements. Also, prototype coverall was significantly different from current coverall at 13 scales among 23 subjective scales. The results identified that prototype coverall design improved auto mechanic's body movement and subjective acceptability.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1643-1645
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• 2005

A newly-built inverter has to undergo a series of stress tests in the final stage of production line. This can be achieved by connecting it to a dynamometer consisting of a three-phase machine joined by a rigid shaft to a DC load machine. The latter is controlled to create some specific load characteristic needed for the test. In this paper a test method is proposed, in which no mechanical equipment is needed. The suggested test stand consists only of a inverter to be tested and a simulator converter. Both devices are connected back- to-back on the AC-side via smoothing reactors. The simulator operates in real-time as an equivalent load circuit, so that the device under test will only notice the behaviour of a three-phase machine under consideration of the load. In odor to wove rightness of the suggested test method, the simulation and actural experiment rallied out emulation for a 2.2kW induction motor.

• Structural Engineering and Mechanics
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• 제70권6호
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• pp.671-681
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• 2019

This paper examines the applicability of artificial neural network (ANN) and multivariate adaptive regression splines (MARS) to predict the compressive strength of bacteria incorporated geopolymer concrete (GPC). The mix is composed of new bacterial strain, manufactured sand, ground granulated blast furnace slag, silica fume, metakaolin and fly ash. The concentration of sodium hydroxide (NaOH) is maintained at 8 Molar, sodium silicate ($Na_2SiO_3$) to NaOH weight ratio is 2.33 and the alkaline liquid to binder ratio of 0.35 and ambient curing temperature ($28^{\circ}C$) is maintained for all the mixtures. In ANN, back-propagation training technique was employed for updating the weights of each layer based on the error in the network output. Levenberg-Marquardt algorithm was used for feed-forward back-propagation. MARS model was developed by establishing a relationship between a set of predictors and dependent variables. MARS is based on a divide and conquers strategy partitioning the training data sets into separate regions; each gets its own regression line. Six models based on ANN and MARS were developed to predict the compressive strength of bacteria incorporated GPC for 1, 3, 7, 28, 56 and 90 days. About 70% of the total 84 data sets obtained from experiments were used for development of the models and remaining 30% data was utilized for testing. From the study, it is observed that the predicted values from the models are found to be in good agreement with the corresponding experimental values and the developed models are robust and reliable.

• 국제물리치료학회지
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• 제10권2호
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• pp.1774-1778
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• 2019

Background : Methods of wearing a baby carrier have suggested; however, there have been no studies suggesting ideal ways. Objective : To investigate muscular fatigue and balance of the waist during baby carrier are worn on the front, the side, and the back of the body. Design: Randomized controlled clinical trial (single blind) Methods : The subjects of this study were 20 healthy men and women in their 20s, who underwent tests of muscular fatigue and balance of the waist bones based on types of wearing baby carrier. Electromyogram (EMG) patches were attached to the L2 and the L4 for testing muscular fatigue, while a device for measuring proprioceptive senses was used to assess balance ability. The measurements were performed before wearing the baby carrier and after 30 minutes of normal walking. The methods of wearing the baby carrier included wearing on the front, the side, and the back of the body. Results : The time taken to adjust the balance was shorter than other types of wearing during the baby carrier were worn on the side, and the ratio of lumbar flexion and relaxation was shown insignificant. Conclusions : These results suggested that wearing the carriers on the side was most effective on reducing fatigue and enhancing balance ability of the waist.

• Physical Therapy Rehabilitation Science
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• 제10권4호
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• pp.450-456
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• 2021

Objective: Studies confirming the lumber spine kinematics of direct or indirect segmental mobility under the application of joint mobilization, which induces passive force on the spine, are insufficient.Therefore, this study aims to obtain the underlying clinical data by identifying direct or indirect segmental mobility produced by Maitland's PA mobilization technique. Design: Randomized controlled trial design. Methods: Thirty subjects with no back pain participated in this study. X-ray testing equipment (SIG-40-525, Ecoray Inc., Korea) was used to verify the segmented movement of their lumbar. Joint mobilization was performed by physiotherapists with more than 10 years of experience in prescription therapy, and radiography was performed once without PA joint mobilization and once without the mobilization for comparing the lumbar vertebrae before and after the mobilization. The radiographs taken were analyzed using the picture archiving and communication system (PACS) program to measure the spinal displacement, intervertebral height, intervertebral angle, and lumbar lordosis angle. Results: Significant differences were observed in the lumbar displacement, intervertebral angle, and lumbar lordosis angle in all lumbar vertebrae before and after the mobilization. The intervertebral height indicated significant differences in all ventral vertebrae and only in L3-L4 and L4-L5 in dorsal vertebrae. Conclusions: This study suggests that the segmental mobility produced through indirect approaches plays an important role in inducing therapeutic effects in patients with back pain.

• 한국공간구조학회논문집
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• 제24권2호
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• pp.53-63
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• 2024

The cultural heritage of fortresses is often exposed to external elements, leading to significant damage from stone weathering and natural disasters. However, due to the nature of cultural heritage, dismantling and restoration are often impractical. Therefore, the stability of fortress cultural heritage was evaluated through non-destructive testing. The durability of masonry cultural heritages is greatly influenced by the physical characteristics of the back-fille material. Dynamic characteristics were assessed, and endoscopy was used to inspect internal fillings. Additionally, a finite element analysis model was developed considering the surrounding ground through elastic wave exploration. The analysis showed that the loss of internal fillings in the target cultural heritage site could lead to further deformation in the future, emphasizing the need for careful observation.

• International Journal of Air-Conditioning and Refrigeration
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• 제12권4호
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• pp.184-191
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• 2004

In order to improve the performance of a 2 room heat pump with a constant speed compressor, the optimum refrigeration circuit of the heat pump with different cooling and heating capacities is developed by applying capillary tubes. The refrigeration circuit is composed of four parts; a heating circuit, a cooling circuit, a by-pass circuit and a balance circuit. The performance of the 2 room heat pump are investigated from a rating experiment and a reliability experiment, using the calorimeter. Results of the rating experiment show that the capacity of heat pump is about $93\%$ of the design value. In particular, the capacity of the cooling single operation is about $13\%$ higher than the design value, and the capacity of the heating multi operation is about $5\%$ higher than the design value. From the reliability experi-ment, it is found that the lowest driving voltage of the compressor is about $75\%$ of the rating voltage. Also the compressor is reoperated normally under the flood back and the over load.

• 한국지반공학회논문집
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• 제16권1호
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• pp.99-106
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• 2000

기존의 Oedometer 시험은 간단한 시험장치의 편리함으로 인해 널리 이용되어 왔다. 그러나 이 방법은 장시간의 시험기간, 각 단계 하중에서의 불규칙적인 응력상태, 매우 연약한 점토에 대한 시험의 어려움 및 시료의 포화문제와 같은 여러 문제점을 노출하게 되었다. 따라서 이런 단점을 보완 할 수 있는 시험 방법의 하나로 일정 변형률 압밀시험 이 개발되어 널리 이용되고 있다. 본 논문에서는 세가지 변형률을 이용한 CRS시험을 실시하였으며, 이 결과를 수정된 Wissa(1971)의 비선형 이론을 이용해 해석하고, 기존의 Oedometer시험 및 직접투수시험과 비교분석함으로서 CRS시험의 효율성 및 적용성 유무를 판단하고자 한다.

• Toxicological Research
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• 제13권3호
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• pp.237-245
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• 1997

As the development of a pharmaceutical product is a dynamic process which involves continuousfeed-back between non-clinical and clinical studies, the integration of pharmacokinetics into toxicity testing became increasingly important in recent years. Toxicokinetic measurements in the toxicity studies is considered to be an important scientific approach in the interpretation of the toxicology findings and the promotion of rational study design development. Primarily this research project was conducted to determine the systemic exposure achieved in acute toxicity test and its relationship to dose level and the time course of the toxicity study. Acute hepatotoxicity study and its relevant toxicokinetic study in mice were performed using acetarninophen (AA) as a model compound. The correlation between acute hepatotoxicity indices and toxicokinetic parameters following intraperitoneally administration of various dosages of AA in mice was evaluated and discussed minutely in the text. Based on these studies, single-dose toxicity testing of AA including kinetic studies was evaluated in ICR mice for 7 days and interpreted in the text. Our results from the integration of toxicokinetic monitoring into single-dose toxicity study enable to elucidate the relation of the exposure achieved in toxicity study to toxicological findings and assist in the selection of appropriate dose levels for use in repeated-dose toxicity or later studies.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.603-609
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• 2008

개발품의 품질을 평가하기 위해 무엇을 어떻게 시험할 것인가 적합한 모델을 정하는 것은 중요하다. 개발된 제품의 대부분의 패키지화된 소프트웨어는 소스코드를 공개하지 않으므로 외부적인 동작 특성을 측정하여 평가한다. 고속철도 선로변 정보처리 기기는 단일계로 구성되어 있던 것을 최근에 2중화하므로 신뢰성을 향상하도록 개발하였다. 철도에 사용되는 용품에 대하여 성능 및 안전성을 확보하기 위하여 철도안전법에서 공인시험기관에서 품질인증을 받을 수 있도록 하고 있어 우선 규정의 적용 가능성을 검토를 하였다. 아울러 정보처리모듈 일반 및 전용 그리고 절체기에 대하여 H/W 와 S/W의 검증을 위하여 필요한 절차와 성능을 확인하는 방안을 검토하고, TFM(Track-side Functional Module) Tester기와 Simulator를 활용하여 보드별 성능시험을 하는 방안에 대하여 고찰하고자 한다.