• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5B
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• pp.475-481
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• 2011

The TMDL standard flow as applying watershed management regime uses the average low flow of past 10 years. Moreover, the TMDL implementation assessment has been enforced through management of pollutant load satisfied objective water quality. Even though the present allocation and management through averaged low flow are still convenient, they are not enough to solve ultimate goals of watershed management to keep up recovery of water body. To maintain the same water quality concentration, the standard flow is required to consider total discharge in management plan which helps to keep healthy ecosystem. In view of this, it would be possible to approach reasonable assessment by reflecting variably changeable discharge from precipitation-streamflow relation and the TMDL standard establishment considering artificial regulated flow. Therefore, this study attempts to develop the TMDL method using Load Duration Curve (LDC) and Streamflow-Load Rating Curve (QLRC) considering total discharge and finds drawbacks with solutions as applying on Nakdong river TMDL unit watershed. Finally, this research evaluates possibility of application on pollutant load allocating and implementation assessment in Korea.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.4
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• pp.237-245
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• 2011

As necessity of safety re-evaluation for spent fuel storage facility has emphasized after the Fukushima accident, accuracy improvement of heat load evaluation has become more important to acquire reliable thermal-hydraulic evaluation results. As groundwork, parametric and sensitivity analyses of various storage conditions for Kori Unit 4 spent fuel storage pool and spent fuel depletion parameters such as axial burnup effect, operation history, and specific heat are conducted using ORIGEN2 code. According to heat load evaluation and parametric sensitivity analyses, decay heat of last discharged fuel comprises maximum 80.42% of total heat load of storage facility and there is a negative correlation between effect of depletion parameters and cooling period. It is determined that specific heat is most influential parameter and operation history is secondly influential parameter. And decay heat of just discharged fuel is varied from 0.34 to 1.66 times of average value and decay heat of 1 year cooled fuel is varied from 0.55 to 1.37 times of average value in accordance with change of specific power. Namely depletion parameters can cause large variation in decay heat calculation of short-term cooled fuel. Therefore application of real operation data instead of user selection value is needed to improve evaluation accuracy. It is expected that these results could be used to improve accuracy of heat load assessment and evaluate uncertainty of calculated heat load.

• Journal of Korean Society of Transportation
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• v.35 no.6
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• pp.545-556
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• 2017

Various assessment indexes have been developed and utilized to evaluate the driver workload. However, existing workload assessment indexes do not fully reflect driving habits and driving patterns of individual drivers. In addition, there exists significant differences in the amount of workload experienced by a driver and the ability to overcome the driver's workload. To overcome these limitations associated with existing indexes, this study has developed a novel workload assessment index to reflect an individual driver's driving pattern. An average of the absolute values of the steering velocity for each driver are set as a threshold value in order to reflect the driving patterns of individual drivers. Further, the sum of the areas of the steering velocities exceeding the threshold value, which is defined as erratic steering area (ESA) in this study, was quantified. The developed ESA index is applied in evaluating the driver workload of manually driven vehicles in automated vehicle platooning environments. Driving simulation experiments are conducted to collect drivers' responsive behavior data which are used for exploring the relationship between the NASA-TLX score and the ESA by the correlation analysis. As a result, ESA is found to have the greatest correlation with the NASA-TLX score among the various driver workload evaluation indexes in the lane change scenario, confirming the usefulness of ESA.

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.10a
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• pp.262-262
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• 2021

• 한국가스학회:학술대회논문집
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• 2003.10a
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• pp.53-58
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• 2003

API 5L X65 배관에 50mm이상의 단관을 삽입하여 용접하였을 경우, 삽입된 단관 길이 변화에 따른 용접부 기계적 특성 평가 결과를 요약하면 다음과 같다. 1. 단관삽입 용접부위의 거시적 조직관찰, 미소경도측정, 인장시험, 굽힘시험을 수행한 결과, 단관삽입 용접부의 건전성에는 문제가 없는 것으로 평가되었다. 2. 단관삽입 용접부의 원주방향 최대 인장 잔류응력의 크기는 단관 삽입 길이에 관계없이 약 150MPa로서 그리고 최대 압축 잔류응축은 약 300MPa로 측정되었다. 모재의 항복강도가 492MPa인 것과 비교하여보면 단관 삽입 용접에 의한 잔류응력의 영향은 매우 작은 것으로 평가되었다.

• Journal of Welding and Joining
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• v.15 no.3
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• pp.1-11
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• 1997

용접이음부에서는 피로크랙 전파거동이 모재와 다르다는 것은 이미 알려져 있으며 그 원인으로서는 용접부에 있어서의 금속조직의 변화와 잔류응력 등이 일컬어 진다. 금속조직의 변화에 따른 영향에 대하여서는 비교적 그 영향이 작으며 또한 피로 크랙 전파속도에 대해서 안전한 쪽으로 역할을 한다고 보고되어져 있다. 따라서 용접 이음부에 있어서의 피로크랙 전파에 대하여서는 주로 잔류 응력의 영향에 주목하여, 잔류응력이 피로크랙의 전파속도에 어떻게 영향을 미치는가를 파악하여야 한다. 이러 한 관점에서 지금까지 용접잔류응력장을 전파하는 피로크랙을 대상으로 하여 잔류응력 이 피로크랙 전파에 미치는 영향을 정량적으로 평가하고자 하느 시도가 많은 연구진에 의해 수행되어 왔다. 표1에 이러한 연구의 흐름을 평가방법과 평가에 고려된 사항을 중심으로 나타내었다. 이러한 배경으로부터, 본고에서는 피로크랙 전파거동에 미치는 잔류응력의 영향에 대해서 지금까지 수행된 연구의 내용을 연구 발전형태에 주목하여 검토하였다.

• Defense and Technology
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• no.7 s.137
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• pp.68-75
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• 1990

지난 수년간 외국의 병기와 군사장비에 대한 시험 및 평가를 포함한 미 국방부의 2가지 프로그램은 국방관계 잡지와 신문등 매스컴의 주목을 받아왔다. 어느 나라의 방산업체에 조달을 맡길 것인가의 문제, 조달을 수행할 나라들이 제출한 계획의 수치, 그리고 미군의 타개책등이 국방성 관계자들에 의해 검토되어 왔으며, 해외로부터 방위장비를 구입할때 미국 방산업체에 미치는 영향등에 대해 면밀한 조사와 평가가 이루어져 왔다. 미 국방부의 이러한 노력은 외국산 병기평가(FWE)계획과 나토 장비류 비교시험(NCT) 계획으로, 뚜렷이 나타나고 있다. 이글은 FWE와 NCT에 대한 미 국방부의 시각을 밝히고, 이 두 프로그램에서 미 국방부가 조달 후 후보업체를 지명하는 방법에 대해 서술된 것으로, 외국 방산업체들에게 좋은 자료가 될 것으로 사료된다.

• Korean Journal of Construction Engineering and Management
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• v.8 no.3
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• pp.134-141
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• 2007

It is crucial that the WRMSD is realized as a critical job-related diseases for the construction workers. It is caused by the characteristics of repetitive work, uncomfortable work methods and continuous unsuitable physical posture. The objective of this research is to evaluate the workload for the carpenters and structural steel workers. Investigation on the posture and behavior for the workers as well as personal sensitivity to the workload is conducted. The laboratory tests with graduate students are conducted to estimate inconvenience in terms of personal sensitivity to the workload. The results of this research will be used to perform the further researches on ergonomic and technological approaches to improvements of the hand-intensive tasks in the construction industry.

• Composites Research
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• v.21 no.4
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• pp.22-28
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• 2008

The composite joint has become an important research area because the structural efficiency of a structure with a joint is determined by its joints rather than by its basic structure since the joints are often the weakest areas in composite structures. In this paper, the strengths of adhesive joints consisting of metal and composites were predicted and tested by the maximum strain theory and damage zone theory. Nonlinear finite element analyses of adhesive Joints considering the material nonlinearity of the adhesive layer were performed. From the tests and analyses, the strengths of the adhesive joints could be predicted to within 22.2% using the damage zone ratio.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11a
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• pp.183-186
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• 2002

클러스터는 부하 분산 스케줄링의 방법에 따라서 그 시스템의 성능이 달라진다. 본 논문에서는 클러스터의 한 종류인 LVS에서 제시되었던 RR, WRR, LC, WLC의 부하 분산 스케줄링을 이용하여 시스템의 각종 부하를 처리하는 방법과 클러스터의 각 서버의 성능을 측정하여 부하 분산을 결정하는 ALBM(Adaptive Load Balancing Mechanism) 방식을 비교하였다. 이 성능 평가를 하기 위하여 여러 실험 환경 설정을 하여 다양한 실험을 통하여 비교 분석 하였다. 실험을 통하여 ALMB 이 기존의 여러 스케줄링 방식에 비하여 전체적으로 좋은 성능 결과를 낳았으며 클러스터 서버간의 안정적인 부하 분산이 되는 결과를 얻었다.