• Journal of Advanced Marine Engineering and Technology
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• v.33 no.2
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• pp.336-343
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• 2009

Because ships are very isolated and independent objects when sailing on the ocean, if a fire and smoke occurs, nobody can be sure to escape safely from ship at the moment. On the focus of the relationship between the sight transmissivity by fire smoke density and the life safety, this study performs simulations and experiments, respectively. To evaluate the theoretical evacuation time, CFAST software which is known as a 2 zone model analysis tool is used, and the result is 54 seconds from ECR(Engine Control Room) exit to upper deck exit and 34 seconds from bosun store to upper deck exit. And totally 12 types of experiments are performed with other 10 persons per experiment. As the result, it is cleared that the low sight transmissivity leads to the low life safety and the obstruction which can be happen unexpectedly on the evacuation way on fire makes it worse. At the condition of the smoke density 0%, over 90% people arrive at upper deck exit safely. But with the transmissivity of 8%, 70%(from ECR) and 30%(from bosun store) among experiment persons of each can survive, and with same density and unexpected obstruction, the survival ratio goes down to only 20% and 10%.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.53-62
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• 2015

Recently, number of tablet or Smartphone users increased significantly in domestic and around the world. But violation of personal information such as leakage, misuse and abuse are constantly occurring by using mobile devices which is very useful in our society. Therefore, in this paper it will talk about the problems in the network environment of the mobile environment such as tablet and Smartphone, Mobile Malware, hacking of the public key certificate, which could be potential threat to mobile environment. This thesis will research for people to use their mobile devices more reliable and safer in mobile environment from invasion and leakage of personal information. In order to use Smartphone safely, users have to use Wi-Fi and Bluetooth carefully in the public area. This paper will research how to use App safely and characteristic of risk of worm and Malware spreading. Because of security vulnerabilities of the public key certificate, it will suggest new type of security certification. In order to prevent from the information leakage and infect from Malware in mobile environment without knowing, this thesis will analyze the improved way to manage and use the mobile device.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.5
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• pp.96-103
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• 2009

This paper describes a humanoid robot's intelligent foot with two six-axis force/moment sensors. The developed humanoid robots didn't get the intelligent feet for walking on uneven surface safely. In order to walk on uneven surface safely, the robot should measure the reaction forces and moments applied on the sales of the feet, and they should be controlled with the measured the forces and moments. In this paper, an intelligent foot for a humanoid robot was developed. First, the body of foot was designed to be rotated the toe and the heel to all directions, second, the six-axis force/moment sensors were manufactured, third, the high-speed controller was manufactured using DSP(digital signal processor), fourth, the humanoid robot's intelligent foot was manufactured using the body of foot, two six-axis force/moment sensors and the high-speed controller, finally, the characteristic test of the intelligent foot was carried out. It is thought that the foot could be used for a humanoid robot.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3942-3949
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• 2010

Since existing Nate-on Messenger application stores users' personal information in the database of its server, it is extremely venerable to internal threats, not to mention the communication data being transmitted without any safety measures. To solve such problematic areas of the existing application, we have developed a safer messenger application. The messenger application proposed in this paper discloses only the least required personal information of its users and the rest of the personal information is safely encrypted in the database using private passwords. This protective measure prevents the administrator or a third party from misusing the information since he/she will not be able access the information. In addition, users will be able to freely and safely communicate using this new messenger since transmitted data will also be encrypted.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.575-584
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• 1996

The objective of this paper is to develop an expert system for nuclear piping integrity. This paper describes the selection methodology of integrity evalution method and the inference of material properties. To select the integrity evaluation method, the weight factor for respective material properties was obtained by the sensitivity analysis of the effect of material properties on integrity evaluation method. Subsequently the possession ratio for respective integrity evaluation method was computed, and the most appropriate integrity evaluation method for given input information is selected. In the material properties inference, stress-strain curves and J-R curves were predicted from tensile properties such as yield strength and tensile strength.

• The Korean Journal of Health Service Management
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• v.10 no.2
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• pp.205-216
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• 2016

Objectives : The purpose of this study was to determine the association between musculoskeletal workload and job stress in early childcare teachers. Methods : This study was based on The Korean Working Condition Survey conducted on wage workers. The total number of individuals included in the analysis was 395 (286 childcare teachers and 109 kindergarten teachers) early childcare teachers in 2011. The collected data were analyzed by frequency statistic, cross-tabulation analysis and logistic regression. Results : The adjusted odds ratio showed a statistically effective association for job stress exposure. The results were as follows: education level, service environment, emotional labor, fatigue or posture led to pain for a high level of job stress. Additionally, for childcare teachers, the results showed that fatigue or posture led to pain when moving a heavy object frequently. Conclusions : When childcare teachers are assigned a task to lift heavy or awkward or objects, care should be taken on who is assigned the task, and it should be done safely. An intervention program should be developed to train childcare teachers to safely and efficiency do heavy labor in early childcare education classes.

• Journal of Computing Science and Engineering
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• v.3 no.4
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• pp.195-215
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• 2009

Worst-case execution time (WCET) analysis is critical for hard real-time systems to ensure that different tasks can meet their respective deadlines. While significant progress has been made for WCET analysis of instruction caches, the data cache timing analysis, especially for set-associative data caches, is rather limited. This paper proposes an approach to safely and tightly bounding data cache performance by computing the worst-case stack distance of data cache accesses. Our approach can not only be applied to direct-mapped caches, but also be used for set-associative or even fully-associative caches without increasing the complexity of analysis. Moreover, the proposed approach can statically categorize worst-case data cache misses into cold, conflict, and capacity misses, which can provide useful insights for designers to enhance the worst-case data cache performance. Our evaluation shows that the proposed data cache timing analysis technique can safely and accurately estimate the worst-case data cache performance, and the overestimation as compared to the observed worst-case data cache misses is within 1% on average.

• The KIPS Transactions:PartB
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• v.9B no.4
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• pp.459-464
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• 2002

In this paper, we propose a private digital watermarking method based on a wavelet transform to protect digital contents copyrights. We find out the optimal watermark insertion region and the optimal amount of watermark in order to satisfy robustness and imperceptibility against various attacks such as noise, compression, collusion, clipping, scaling to transfer the contents safely. Through this experiment, we could find out the adequate location of watermark insertion and proper amount of watermark, and transfer the watermarked image safely.

• Korean Security Journal
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• no.5
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• pp.309-325
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• 2002

It was because mankind could use the fire that we have been civilized. creating a brilliant culture and developing an industrial society. While fire is very useful to our life, the number of the victims of fire continues to increase, This study suggests the ways to rescue the people safely when they are subject to a fire in a high-rise building. To this end, the concept of fire is reviewed. Fire breaks out when the conditions for congestion are met, and therefore. if any of the conditions can be blocked, the fire will be extinguished. In other words. the knowledge of such conditions will greatly help the fire fighters to rescue the people, and so. such conditions for congestion as flammable, heat, oxygen and chain reaction are examined. In addition, the effects of such by-products of fire as heat and smoke on human body are reviewed. In order to rescue the people more safely, the fire fighters are requested to review the situation and design a rescue strategy before being engaged in a full-scale rescue activity. This study discusses various rescue methods using such passages or equipments as stair case, double ladder, special fire fighting vehicle, elevator, jumar, rope, helicopter, etc. In conclusion. since it is more difficult to rescue the people from a high-rise building than from the ground, it is essential to design a rescue program not after fire but before it and thereby, minimize the number of victims.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.115-121
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• 1999

Marine casualties of dangerous cargo carriers lead to not only the loss of human life and properties, but also marine pollution caused by spilled oil and hazardous cargo. So the prevention of marine casualties and emergence response to minimize pollution are very important problems to be settled. But until now, most of salvage assistance jobs have been done based on rule of thumb without any technical support. It is not easy to cope with the incidents safely and rapidly under the current situation. The purpose of this paper is to develop a systematic and engineering salvage assistance tool available in the casualty sites. This paper contains the construction of salvage system, classification of technical items, and prototype system for the safety assessment. The developed system enable a salvage engineer in his/her salvaging jobs to perform safely and promptly.