• Journal of Biosystems Engineering
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• 제13권4호
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• pp.1-8
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• 1988

A series of soil bin experiments was carried out on land to evaluate the soil physical properties whether they are pertinent to soil-wheel system and to investigate if true model theory u applicable to powered rigid wheel-soil system. Four different sized wheels having diameter of 45, 60, 75 and 90 em were wed for the experiment. The following conclusion was derived from the study. (1) True model theory can be sufficiently utilized to study the wheel traction and linkage on lands. (2) For both dry and wet sands, Cone Index(CI) and soil shear parameters (c, ${\phi}$) with bulk density (${\gamma}$) were found to be good measures of soil physical properties which are pertinent to predict the performance of the powered rigid wheel-soil system.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.180-187
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• 2017

항공기 엔진 지상 성능시험을 위한 15만 파운드 급 Test 설비를 구축하기 위해 Test Cell Type, Cell Flow, Cell Bypass Ratio, Approach Velocity, Cell Depression, Front Cell Distortion, Noise 및 Vibration 등의 주요 설계 목표를 설정 하였고, 설비 완공 후 최종 성능검사를 통해 목표 값을 충족하는 성능 데이터를 획득할 수 있었다.

• 한국항해항만학회지
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• 제32권6호
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• pp.439-445
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• 2008

실습선 한바다호에 설치된 선박 조종성능 계측 시스템을 이용하여 타각, 선회방향, 속력 등 다양한 조건으로 수차례에 걸쳐 선회시험을 실시하였다. 이를 바탕으로 선회권, 조종성 지수, 신침로 거리 등을 산출하여 상호 비교하였고, 그 결과 IMO 조종성 기준(Maneuvering standards)을 잘 만족하고 있음을 확인하였다. 실습선 한바다호는 좌현으로 선회하는 경우 모든 타각에서 선회권이 작게 측정되었고, 타 선박과 비교하여 선회성 지수(K)와 추종성 지수(T)가 상대적으로 크게 나타났다. 따라서 선회과정에서 선회경은 다소 작아질 수 있으나, 전진거리가 길어질 수 있으므로 전방의 위험물 회피에 주의가 요구된다. 또한, 신침로가 $30^{\circ}{\sim}90^{\circ}$인 경우 신침로거리는 $125m{\sim}300m$로 측정되었다. 이러한 결과는 충돌회피와 항내조선 및 협수도 항해 시 선박을 보다 안전하게 조선하는데 매우 중요한 지표가 될 것으로 판단된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 추계 학술발표회
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• pp.334-408
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• 2006

In Hong Kong, large-diameter (${\ge}600mm$) bored piles and large-section excavated rectangular barrettes are commonly used to support tall buildings to resist both vertical and horizontal loads. These piles and barrettes penetrate through and may found in saprolitic soils and decomposed rocks. Generally, the design of these large bored piles and barrettes involves considerable amount of uncertainty and design parameters must usually be verified by field tests. In this paper, over 50 full-scale load tests on large-diameter bored piles and over 15 large-section of rectangular barrettes in Hong Kong are reviewed and interpreted critically, in particular the degree of mobilisation of side shear resistance using a mobilization rating (MR) factor and a displacement index (DI) for floating bored piles and barrettes and rock-socketed piles, respectively. The author was heavily involved with many of these load tests. The diameter of the bored piles tested ranges from 0.6m to 1.8m and the depth varies from 12m to 75m. Sizes of barrettes critically reviewed include $2.2m{\times}0.6m,\;2.2m{\times}0.8m,\;2.8m{\times}0.8m\;and\;2.8m{\times}1.0m$ (on plan) and the depth varies from 36m and 63m. Based on these field tests, a new failure load criterion for large-diameter bored piles and barrettes is developed and proposed. The side shear resistance of the bored piles and barrettes is quantitatively analyzed with respect to local displacements, standard penetration tests, unconfined compressive strength (UCS) for rock sockets and using the effective stress principle. In addition, the effects of construction including post-grouting, construction time, side scraping and excavation tools on side shear resistance are investigated and reported.

• 기술혁신학회지
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• 제10권2호
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• pp.284-309
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• 2007

본 연구는 2002년부터 5년간 운영된 권역별 공공기술이전컨소시엄의 실증분석을 통하여 기술이전컨소시엄의 유효성과 주요 특성요인을 살펴보고자 한다. 유효성 검정은 기술이전프로세스를 토대로 하여 개발된 기술이전효율성지수가 컨소시엄의 운영기간 동안 변화한 정도로 판단하였고, 특성요인의 탐색은 기술이전 메커니즘 연구의 핵심변수인 가입동기, 촉진요인, 장애요인 및 극복과제를 사용하여 이루어졌다. 그 결과, 기술이전컨소시엄에 참여한 대학 또는 정부연구기관의 기술 이전효율성지수가 참여하지 않은 기관에 비하여 더욱 큰 증가를 보였으며, 조사된 특성요인들도 컨소시엄의 직접참여자 그룹과 간접참여자 그룹간에 인식 차가 거의 없는 것으로 판명되었다. 본 연구는 기술이전컨소시엄이 새로운 기술이전 메커니즘으로서의 유의미성과 공통적 특성을 갖는지를 탐색해 보았다는 것에 그 의의가 있다.

• 대한한방내과학회지
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• 제39권3호
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• pp.313-322
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• 2018

Objectives: Wild ginseng pharmacopuncture is widely used in oriental medicine. However, there is no standard method for efficiently extracting the active ingredient. In this study, in order to determine an efficient extraction method, wild ginseng was extracted by the distillation and 70% ethanol reflux methods, respectively. In comparing each extract, the index compounds were analyzed, and antioxidant activity was measured. Methods: The index compounds, ginsenoside Rg1 and ginsenoside Rb1, were detected using high performance liquid chromatography (HPLC). Antioxidative activities of total phenolic compounds, DPPH (${\alpha}$, ${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) and FRAP (ferric reducing antioxidant power) were measured to compare their bioactivities. Since saponin is known to be hemolytic, the hemolytic activity of each extract was compared. Results: The index compounds were analyzed. Nothing was detected in the wild ginseng distilled extracts (WGDE). In the wild ginseng 70% ethanol reflux extracts (WGEE), ginsenoside Rg1 was 3.66 mg/g, and ginsenoside Rb1 was 16.70 mg/g. WGEE showed higher levels than WGDE in all antioxidative activities. In the hemolytic test, the extracts showed almost no toxicity, but WGEE showed lower toxicity than WGDE. Conclusions: In this study, it was concluded that WGEE is more advantageous than WGDE in the detection of index compounds and bioactivity. However, additional studies of additional extraction methods and other bioactivity tests are needed.

• 한국안전학회지
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• 제26권6호
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• pp.79-84
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• 2011

There have been so many studies related to job stress or musculoskeletal disorders(MSDs) in the shipbuilding industry. However, study of employee performance evaluation that reflect on the industrial features of the deckhouse manufacturing industry has not been established. Therefore, this study aimed to evaluate workers' job stress and work ability through statistical significance tests according to age, work types, years of service, work forms and sex. For this, the study conducted a job stress test using the Korean Occupational Stress Questionnaire Short Form, and employee performance evaluations using the Work Ability Index(WAI) of the Finnish Institute of Occupational Health (FIOH) on 536 workers in the deckhouse manufacturing industry. MINITAB statistics program was used for statistics analysis and significance was verified with the Kruskal-Wallis test, a corporate body of nonparametric statistical analysis. As a result, employee performance had significant differences, depending on age, work types, years of service and sex, and job stress also depended on the number of service year and work form. Additionally, it was found that employee performance decreased more as job stress increased.

• 한국ITS학회 논문지
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• 제15권2호
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• pp.13-23
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• 2016

기존의 많은 돌발상황 자동감지 알고리즘은 복잡한 구조와 계산 과정, 수많은 매개변수, 그리고 필터링/평활화 같은 선 작업 때문에 지속적인 유지관리가 사실상 중단된 상태이고 오보율 또한 높아 많은 교통관리센터로부터 기피 대상이 되고 있는 등 돌발상황감지의 주력 수단으로서 자동 알고리즘의 지위가 위태해진 현실은 매우 우려할만하다. 본 연구에서는 상대 점유율과 속도 항을 활용하여 적체 교통량이라는 신 개념을 도입, 구조가 아주 간단하면서도 검측 원시자료의 보정이 거의 필요 없는 DiFI(Displaced Flow Index) 기반의 돌발상황 자동감지알고리즘을 개발하였다. DiFI 알고리즘의 성능평가는 2003년도 내부순환로 검지기자료를 활용하여 검증을 수행하였으며, 2011년도 경부고속도로 검지기 자료를 수집 정리하여 이식성 검사를 이행하였다. 성능평가는 검지율, 오보율, 평균검지시간, 기타 CR, CI, PI를 사용하였는데 100%의 검지율과 2.99%의 낮은 오보율, 1분을 약간 초과하는 평균검지시간을 보였다. 이는 SAO는 물론 국내 현장에 가장 많이 접목된 APID 및 DELOS 등과 비교해서도 모든 면에서 우월한 성능을 보이는 것이었다.

• 한국소음진동공학회논문집
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• 제24권1호
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• pp.35-44
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• 2014

Sound pressure levels in the receiving room while testing airborne sound insulation performance are varied by the measuring points. This may increase the measurement error, then decrease the measurement reliability. With this reason the research has carried out on the method to reduce deviations of sound pressure level in the ISO type rectangular laboratory focusing on the measurement of airborne sound insulation performance. Tests were made to see the effect of sound absorption in the receiving room, loudspeaker locations, microphones locations and flanking transmission path. Consequently, it was resulted that sound absorption in the receiving room and the loudspeaker location have influence on the sound level deviations especially in the low frequency. The microphone location was very important to get measurement reliability. The effective measuring point, which the sound level difference with average sound pressure level is within 2 dB, could yield most reliable average sound pressure level. Therefore it is necessary to find the effective measuring points in the receiving room. Flanking transmission path should be sealed using sound absorber or magnet etc. to prevent from lowering the sound insulation performance.

• 한국산업보건학회지
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• 제15권2호
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• pp.144-152
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• 2005

To evaluate the effect of lead biomarkers including bone lead on neurobehavioral test in lead workers, 652 lead workers without any occupational exposure to organic solvent, mercury and arsenic were agreed to participate this study. For the control subjects 102 non-occupationally lead exposed blue collar workers in general manufacturing industries were also joined this study. All study subjects joined this study with written informed consent. The study variables of lead exposure were blood and patella lead. For the general characteristics of study subjects, standardized questionnaire regarding age, sex, past disease history, job duration, body mass index (BMI), drinking and smoking habit were provided. For the past history of neurotoxicity related diseases, all study subjects were interviewed by qualified occupational health physician. The results obtained were as follows: 1. Compared with controls without occupational lead exposure, lead exposed subjects had worse performance on all tests(p<0.05). 2. After adjustment for covariates (age, sex, job duration, education level, BMI, smoking and drinking status), the signs of the regression coefficients for blood lead were negative for 13 of the 14 tests. Blood lead was a significant predictor of poorer scores on 8 tests (simple reaction time(ms & root MSD), Trail-Making Test B, Digit Symbol Substitution, Purdue Pegboard assembly, Digit Span Test, Benton Visual Retention, and Purdue pegboard both hand). 3. After adjustment for covariates (age, sex, job duration, education level, BMI, smoking and drinking status), the signs of the regression coefficients for patella lead were negative for 12 of the 14 tests. Patella lead was a significant predictor of poorer scores on 8 tests (simple reaction time(ms). Purdue Pegboard assembly, Digit Span Test, Benton Visual Retention. Pursuit Aiming rest (no. of correct & no. of incorrect), Purdue pegboard non-dominant hand and both hand). With above results, blood lead and patella lead were associated with poorer performance of neurobehavioral tests. In addition, patella lead was confirmed to be better predictor of manual dexterity test in neurobehavioral test battery in lead workers