• 한국산림과학회지
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• 제104권3호
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• pp.488-494
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• 2015

경영 표준진단표를 통해 재배자 스스로 경영 진단을 할 수 있도록 하고 이를 참고하여 임가 경영 개선에 도움이 되고자 떫은감 경영 표준진단표를 개발하여 주산단지의 임가를 대상으로 적용하였다. 떫은감 경영 표준진단표는 임가 일반 현황과 경영 성과 지표, 그리고 경영 진단을 위한 3개의 대분류 항목과 18개의 중분류 항목으로 구성되어 있다. 떫은감 경영 표준진단표 작성을 위해 떫은감 주산단지 10개 시 군 241임가의 경영 실태 조사를 실시하였으며 경영수준 진단을 위해서 18개 중분류 항목의 점수를 합산하여 총점을 산출하였다. 조사 결과 241임가의 평균 점수는 57.4점이었으며 전체 임가의 62%가 40점 이상 60점 미만에 해당하는 것으로 나타났다. 세부 진단항목 결과를 살펴보면 경영기반 지표에서는 나무높이 항목의 점수가 충남 지역에서만 평균 점수보다 현저히 낮은 점수를 나타냈는데 이는 조사 지역의 나무가 30년 이상 된 고령목들이 많아 영향을 준 것으로 생각된다. 생산기술 지표에서 결실조절 항목의 전국 평균 점수는 1.96점으로 상당히 낮은데 떫은감은 단감과 달리 적뢰 적과를 거의 하지 않고 자연 낙과를 통해 스스로 조절하는 경우가 많기 때문이다. 경영 및 판매능력 지표의 자재구입 항목에서는 전국 평균 점수가 2.01점으로 조사 임가의 60% 이상이 대부분의 자재를 개별적으로 선택하고 협상하여 구입한다고 응답하였다. 공동으로 구입한다고 응답한 임가들은 대부분 작목반 단체로 구입하는 경우인 것으로 나타났다.

• Journal of Preventive Medicine and Public Health
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• 제26권1호
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• pp.20-36
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• 1993

Work-related low back pain is one of the major factors that cause the loss of working power especially in actively working age, therefore controlling the work-related low back pain is one of the major issues in the field of industrial safety and health. This study was performed for detecting the risk factors and proposing the efficient control program of the work-related low back pain. The subjects were male workers employed at the manufacturing industry in Pusan with longer than 6 months' working duration. The data was collected by self-reported questionnaire and interview from May 1 to October 31,1992. The contents of questionnaire were as follows:. the experience of low back pain within the recent one month, general characteristics(age, marital status, education level, religion, regular exercise), physical characteristics(height, weight), employment status(working duration, daily working hours, rest during work, satis(action fur the job), type of work and working environments(posture, forward bending, lifting and movement, satisfaction for table and chair). The result was analyzed for 608 entire respondents by case-control comparative method. The number of cases was 152 with a history of work-related low back pain, so the relative frequency of self-reported work-related low back pain was 25.0%, and the number of controls was 344 without any history of low back pain. As a result, two characteristics of the employment status(working duration, satisfaction fur the job) and all characteristics of type of work and working environments showed a statistical significance between the case and control groups(p<0.01). The Oddb ratios of these variables for Work-related low back pain were calculated. They were 7.88 for the satisfaction fur chair, 7.86 for lifting and movement,3.31 for satisfaction for table, and 2.22 fur bending forward(p<0.01). And for the multivariate logistic regression analysis confirmed that unsatisfaction for table was independent risk factor for Work-related low back pain. In summary, though this study was based upon the self-reported questionnaire and the subjective complaints, the satisfaction for chair, lifting and movement, satisfaction for table, and bending forward concerned with the type of work and working environments were considered as the main factors causing the work-related low back pain, and the work-related low back pain may be preventable by the ergonomic control of these factors.

• 한국지반공학회논문집
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• 제37권11호
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• pp.71-81
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• 2021

본 연구는 액상화 현상을 모사할 수 있는 1g 진동대 실험(Shaking table test)을 이용하여 포화 사질토 지반 위 제방 존재 유무에 따른 지반 조건 대상으로 재액상화 거동에 대하여 연구하였다. 실험에 사용된 지반은 실리카 모래를 사용하였으며, 지반조성은 액상화층 50cm(Case 1)와 비액상화층 17.5cm와 액상화층 32.5cm인 경우(Case 2)로 2가지 조건으로 수중낙사법을 이용하여 조성하였다. 제방은 높이 10cm, 사면 기울기는 1 : 1.8 비율로 고정하여 조성하였다. 지진파는 5Hz의 정현파를 8초간 가진을 진행하여 총 1차부터 5차 가진을 수행하였다. Case 1의 경우 자유장 위치에서 1차 가진 시 모든 깊이에 액상화가 발생하였으며, 3차 가진 시 5cm 깊이를 제외한 모든 깊이에서 액상화 현상이 발생하지 않음을 확인하였다. 제방 중심 위치에서는 1차 가진 시 20cm 깊이까지 액상화가 발생하였으며, 2차 가진 시 5cm 깊이를 제외한 모든 깊이에서 액상화 현상이 발생하지 않음을 확인하여, 제방 구조물 설치 시 재액상화 거동에 대하여 평가하였다.

• 한국산림과학회지
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• 제112권4호
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• pp.515-522
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• 2023

본 연구의 목적은 삼나무와 편백 임분을 대상으로 신규 입목수간재적표 적용이 임목축적, 탄소저장량 및 온실가스 흡수량에 미치는 영향을 정량적으로 평가하여 국내 온실가스 인벤토리 개선방안을 제시하는 것이다. 탄소저장량과 온실가스 흡수량을 산정하기 위해 제6차, 7차 국가산림자원조사에서 동일하게 유지되는 부표본점의 임목축적 자료를 활용하였다. 신규 입목수간재적표 적용에 따른 임목축적의 변화를 평가하고자, 2009년(Ver.1)과 2021년(Ver.2)에 개발된 입목수간재적 표 내 Kozak(1988) 모수를 이용하였다. 입목수간재적표 Ver.2는 Ver.1에 개발되지 않았던 삼나무를 포함하여 16개 수종으로 확대·개발하였고, 과거 부재하였던 흉고직경 30 cm 이상 대경목 정보를 반영하였다. 삼나무와 편백 임분의 임목축적을 산출한 결과, 입목수간재적표 Ver.2를 적용했을 때 Ver.1보다 높게 나타났으며, 통계적으로 유의한 차이(p<0.001)가 나타났다. 이러한 결과는 개선된 신규 입목수간재적표를 적용할 때, 온실가스 흡수량이 약 22%(삼나무림), 13%(편백림) 증가할 수 있음을 의미한다. 임목축적 산출방법이 개선됨에 따라 IPCC 가이드라인에 적합한 통계를 산출하기 위해 산림부문 온실가스 통계 재계산이 필요할 것으로 판단된다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.271-274
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• 2009

This paper deals with an evaluation of the product quality according to intermesh of the roller straightening process of a steel cord. To perform the experiments, a single-layered steel cord with three wires is selected as a target. Intermeshes at inlet and outlet of the roller straightening device are selected as a respective design parameter. According to two intermeshes of the roller straightening device, a design table is generated and experiments were performed. Three assessment items of the product quality, such as the residual torsion, the arc-height and the pre-forming ratio, are measured in each experimental case for the quantitative evaluation of a steel cord. Based on the measured data, the sensitivity of two intermeshes was analyzed and the prediction equation for the product quality of a steel cord was also constructed from the regression analysis.

• 한국정밀공학회지
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• 제21권8호
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• pp.65-72
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• 2004

For the burrs formed in machining are irregular and very sharp in shape, it is usually very difficult to measure burr accurately. It was proved that micro burr geometry can be measured imprecision by the Conoprobe sensor using conoscopic holography method. We developed 3D burr measurement system using this sensor. The system is composed of Conoprobe sensor, XY table, controller and 3D measurement program. Some measurements using the developed system are conducted for the burrs formed in micro drilling and piercing. Specific software fur burr measurement includes several function, calculation of burr volume, average burr height. Burs formed on a curved surface were compensated and measured successfully using the basic surface compensation function.

• 국제초고층학회논문집
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• 제5권3호
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• pp.213-220
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• 2016

The "China Zun" tower in Beijing will rise to 528 meters in height and will be the tallest building in Beijing once built. Inspired by an ancient Chinese vessel, the "Zun", the plan dimensions reduce gradually from the bottom of the tower to the waist and then expand again as it rises to form an aesthetically beautiful and unique geometry. To satisfy the structural requirement for seismic and wind resistance, the structure is a dual system composed of a perimeter mega structure made of composite mega columns, mega braces, and belt trusses, and a reinforced-concrete core with steel plate-embedded walls. Advanced parametric design technology is applied to find the most efficient outer-perimeter structure system. The seismic design basically follows a mixed empirical and performance-based methodology that was verified by a shaking table test and other specimen lab tests. The tower is now half-way through its construction.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2007년 가을학술발표회
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• pp.39-52
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• 2007

A new type bridge combining an integral bridge and a pair of geosynthetic-reinforced soil (GRS) retaining walls having full-height rigid (FHR) facings, called the GRS integral bridge, is proposed. The geosynthetic reinforcement layers are connected to the FHR facings (i.e., RC parapets) that are integrated with a girder without using any girder-support. GRS integral bridges are basically much more cost-effective in construction and long-term maintenance while having a much higher seismic stability than conventional-type bridges having a girder via movable and fixed supports on a pair of cantilever abutments. GRS integral bridges are better than bridges using GRS retaining walls as abutments and also than conventional integral bridges with unreinforced backfill. To validate the above, a series of static cyclic lateral loading tests of the facing and a series of shaking table tests were performed on smallscaled models of different bridge types.

• 한국식품영양과학회지
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• 제28권6호
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• pp.1298-1303
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• 1999

For the purpose of improving the qualities of immatured soybean(Seoklyang), the effects of table height (0, 5, 10, 15mm) and time(60, 66, 72, 78 sec) for microwave blanching on physicochemical properties were investigated. Enzyme inactivities lipoxygenase and peroxidase for all there conditions were more de creased than for control and water blanching. Enzyme activity of each conditions was expressed as percentage on the enzyme activity of control. Lipoxygeanse activity and peroxidase activity of immatured soybeans were about 20% and 10% levels, respectively. Also the color showed the higher L(lightness), b(yellowness), chroma(brightness) values, but the lower a(redness) and hue angle. Vitamin C content was worse than for control, but was better than for water blanching. Hardness with a few exceptions showed the higher value for control.

• International Journal of Precision Engineering and Manufacturing
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• 제9권2호
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• pp.44-49
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• 2008

This paper describes the problem of ultraprecision positioning with a ball screw mechanism in the microdynamic range, along with its solution. We compared the characteristics of two ball screw mechanisms with different table masses. The experimental results showed that the vibration resulting from the low stiffness of the ball screw degraded the positioning performance in the microdynamic range for the heavyweight mechanism. The proposed nominal characteristic trajectory following (NCTF) controller was designed for ultra precision positioning of the ball screw mechanism. The basic NCTF control system achieved ultra precision positioning performance with the lightweight mechanism, but not with the heavyweight mechanism. A conditional notch filter was added to the NCTF controller to overcome this problem. Despite the differences in payload and friction, both mechanisms then showed similar positioning performance, demonstrating the high robustness and effectiveness of the improved NCTF controller with the conditional notch filter. The experimental results demonstrated that the improved NCTF control system with the conditional notch filter achieved ultra precision positioning with a positioning accuracy of better than 10 nm, independent of the reference step input height.