• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.47
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• pp.1-10
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• 1998

Testing high reliability devices under nomal operating condition is difficult, because the devices are not likely to fail in the relatively short time available for tests. For most applications it is necessary to accelerate the causes of failure by increasing a stress above its nomal value. Previous accelerated life test(ALT) plans have shown how to find optimum allocation, lowest stress and sample size subject to minimizing the variance of mean life estimator. In these ALT plans, the highest acceptable test-stress was assumed to be specified in advance by the experimenter but there is no guidance for selecting it. This assumption is, however, inappropriate for many applications. Testing devices at too-high stress levels can invalidate the extrapolation model, or introduce failure mechanisms that are not anticipated under nomal operating conditions. In this paper, we propose new 4:2:1 compromise plans using Min-Max method to minimize this risk and present minimized test-stress levels(max, middle, min), and find sample allocation based on Min-Max 4:2:1 compromise plans. In result, we compare previous 4:2:1 compromise plans specified maximum test-stress with Min-Max 4:2:1 compromise plans minimized maximum test-stress.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.651-653
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• 2015

Common Embedded boards like the Arduino, Raspberry Pi, BeagleBone Black, leverages smart home systems, machine tools and various products in our day to day life. Managing and dealing frequent large scale incidents involving recent reagents and hazardous materials can be dangerous and difficult to detect in advance like in an event of an accidents or fires. In this paper I have done research by utilizing an Embedded (BeagleBone Black) boards sensors and RFID management system to detect a hazardous situation like fire in real time and avoiding it by sending out an alert message to the admin user to minimizing the risk. This system provides immediate information to the administrator of any hazardous situation and prevents any accidents from occurring.

• Korean Journal of Bronchoesophagology
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• v.1 no.1
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• pp.142-145
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• 1995

The tracheocutaneous fistula(TCF) may develop infrequently as a complication after tracheostomy. Prolonged tracheostomy tube dependence increases the risk of TCF developing, and in growth of stratified squamous epithelium lines the furrow connecting the tracheal mucosa and the skin, accounting for persistence of the fistulous tract. Such fistulas are a nuisance and create nursing and social problems including poor hygiene, aspiration, difficulty with speech, and depletion of pulmonary reserve. Surgical closure has generally been successful by primary closure, fistulectomy with primary closure, and closure by secondary intention following excision of the tracheocutaneous fistula. No large series compares the efficacy of these techniques and each has its own merits. Recent literature has purposed to minimizing complications. For ten years, from January 1985 to December 1994, the authors experienced 25 cases of TCF which were analyzed in respect to incidence and interval of cannulation, duration between decanulation and fistular closure, precedent disease, closure methods, and complications of TCF repair.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.61
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• pp.213-245
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• 2014

This study has significance in examining the formation requirements and notes for concluding the guarantee contract of minimizing interests and conflicts with the concerned parties by examining issues related to the legal relation and demand payment in the concerned parties and by figuring out the provisions of conformity related to the requirements for demand payment pertinent to the documentary provision in relation to characteristics of demand guarantee. What the concerned parties of using demand guarantee grasp the requirements for demand payment of being compliant with the essence and the guarantee condition of the demand guarantee will lead to possibly preventing a dispute caused by disagreement and being secured the fulfillment of underlying contract. To fulfill a underlying contract that is the objective of issuing the demand guarantee, an effort is needed that minimizes a contract-based risk and a cost by being fully aware of a relevant rule that will be recorded in the terms of payment in the demand guarantee, by reflecting the interests between the concerned parties, and by discussing the payment terms.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.7
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• pp.645-651
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• 2009

Previous studies have introduced the technique of spinous process osteotomy to decompress spinal stenosis, a procedure which aims to afford excellent visualization while minimizing destruction of tissues not directly involved in the pathologic process. However, biomechanically it has not been investigated whether the sacrifice of posterior spinous process might have potential risk of spinal instability or not, even though supra-spinous and inter-spinous ligaments are preserved. Therefore the aim of this study is to evaluate the biomechanical properties after spinous process osteotomy, using finite element analysis. The model of spinous process osteotomy exhibited no significant increase in disc stress or change in segmental range of motion. It is due to the fact that the instability of lumbar spine has been maintained by the two-types of ligaments compared with the prior surgical technique. Therefore, according to the finite element result on this study, this osotetomy was considered to be a clinically safe surgical procedure and could not cause the instability of the lumbar spine.

• PNF and Movement
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• v.6 no.1
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• pp.53-60
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• 2008

Purpose : To describes the important aspects of knee joint movement and function used when applying PNF technique to the lower limb. Method : The knee was a very important roles in the lower limb movement and ambulation. This study summarizes the physiologic movement of knee to the PNF lower extremity patterns. Result : The tibiofemoral joint is usually described as a modified hinge joint with flexion-extension and axial rotation by two degrees of freedom movement. These arthrokinematics are a result of the geometry of the joints and the tension produced in the ligamentous structures. The patellofemoral joint is a sellar joint between the patella and the femur. Stability of the patellofemoral joint is dependent on the passive and dynamic restraints around the knee. In a normal knee the ligaments are inelastic and maintain a constant length as the knee flexes and extends, helping to control rolling, gliding and translation of the joint motions. Conclusions : It is important to remember that small alterations in joint alignment can result in significant alterations in patellofemoral joint stresses and that changes in the mechanics of the patellofemoral joint can also result in changes in the tibiofemoral compartments. Successful treatment requires the physical therapist to understand and apply these arthrokinematic concepts. When applied to PNF low extremity patterns, understanding of these mechanical concepts can maximize patient function while minimizing the risk for further symptoms or injury.

• Journal of Information Processing Systems
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• v.11 no.4
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• pp.509-527
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• 2015

Wireless Video Sensor Networks (WVSNs) have become a leading solution in many important applications, such as disaster recovery. By using WVSNs in disaster scenarios, the main goal is achieving a successful immediate response including search, location, and rescue operations. The achievement of such an objective in the presence of obstacles and the risk of sensor damage being caused by disasters is a challenging task. In this paper, we propose a fault tolerance model of WVSN for efficient post-disaster management in order to assist rescue and preparedness operations. To get an overview of the monitored area, we used video sensors with a rotation capability that enables them to switch to the best direction for getting better multimedia coverage of the disaster area, while minimizing the effect of occlusions. By constructing different cover sets based on the field of view redundancy, we can provide a robust fault tolerance to the network. We demonstrate by simulating the benefits of our proposal in terms of reliability and high coverage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2396-2405
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• 2010

Information System (IS) Outsourcing is one of the powerful alternatives to guarantee the competitive advantages in the rapidly changing business environment. Most studies on IS outsourcing area have focused on the Critical Success Factors(CSFs) influencing the Success of IS outsourcing or the performance measuring the success of IS outsourcing projects. The CSFs or the performances which measures the success of IS outsourcing project have limitations to explain how to succeed in doing IS outsourcing project. This study uses Real Options Approach to make IS outsourcing projects' success by recognizing and minimizing IS outsourcing risks.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.2
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• pp.14-24
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• 2021

This study aims to examine probable human errors when landing an airplane by the use of SHERPA(systematic human error reduction and prediction approach) and propose methods for preventing the predictive human errors. It has been reported that human errors are concerned with a lot of accidents or incidents of an airplane. It is significant to predict presumable human errors, particularly in the operation mode of human-automation interaction, and attempt to reduce the likelihood of predicted human error. By referring to task procedures and interviewing domain experts, we analyzed airplane landing task by using HTA(hierarchical task analysis) method. In total, 6 sub-tasks and 19 operations were identified from the task analysis. SHERPA method was used for predicting probable human error types for each task. As a result, we identified 31 human errors and predicted their occurrence probability and criticality. Based on them, we suggested a set of methods for minimizing the probability of the predicted human errors. From this study, it can be said that SHERPA can be effectively used for predicting probable human error types in the context of human-automation interaction needed for navigating an airplane.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.812-824
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• 2021

In order to reduce risks from the Steam Generator Tube Rupture (SGTR) accident and to meet safety targets, various measures have been analyzed to minimize the amount of fission product (FP) release. In this paper, we propose an introduction of a Containment Filtered Venting System (CFVS) connected to the steam generator secondary side, which can reduce the amount of FP release while minimizing adverse effects identified in the previous studies. In order to compare the effect of new equipment with the existing strategy, accident simulations using MELCOR were performed. As a result of simulations, it is confirmed that CFVS operation lowers FP release into the environment, and the release fractions are lower (minimum 0.6% of the initial inventory for Cs) than that of the strategy which intends to depressurize the primary system directly (minimum 15.2% for Cs). The sensitivity analyses identify that refill of the CFVS vessel is a dominant contributor reducing the amount of FP released. As the new strategy has the possibility of hydrogen combustion and detonation in CFVS, the installation of an igniter inside the CFVS vessel may be considered in reducing such hydrogen risk.