• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.5
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• pp.487-495
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• 2016

In the offshore project such as semi-submersible FPU and FPSO, the free fall type life boat called TEMPSC (Totally Enclosed Motor Propelled Survival Craft) has been installed for the use of an emergency evacuation of POB (People on Board) from the topside platform. For the design of life boat arrangement for semi-submersible FPU in the initial design stage, the drop height and launch angle are required fulfill with the limitation of classification society rule and Company requirement, including type of approval as applicable when intact and damage condition of the platform. In this paper, we have been performed the numerical studies to find proper arrangement for the life boats consider drop height in various environmental conditions such as wave, wind and current. In the calculations, the contributions from static and low frequency (LF) motions are considered from the hydrodynamic and mooring analysis as well as damage angle from the intact and damage stability analysis. Also, Air-gap calculation at the life boat positions has been carried out to check the effect on the life boat arrangement. The air-gap assessment is based on the extreme air-gap method includes the effect of 1st order wave frequency (WF) motions, 2nd order low frequency roll/pitch motion, static trim/heel and set down.

• Journal of Electrochemical Science and Technology
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• v.10 no.4
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• pp.408-415
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• 2019

Electroplating is a widely used surface treatment method in the manufacturing process of electronic parts and uniformity of the electrodeposition thickness is very crucial for these applications. Since many variables including fluid flow influence the uniformity of the film, it is difficult to conduct efficient research only by experiments. So many studies using simulation have been carried out. However, the most popular simulation technique, which calculates secondary current distribution, has a limitation on the considering the effects of fluid flow on the deposition behavior. And modified method, which is calculating a tertiary current distribution, is limited to a two-dimensional study of simple shapes because of the massive computational load. In the present study, we propose a new electroplating simulation method that can be applied to complex shapes considering the effect of flow. This new model calculates the electroplating process with three steps. First, the thickness of boundary layers on the surface of the cathode plane and velocity magnitudes at the positions are calculated from the simulation of fluid flow. Next, polarization curves of different velocities are obtained by calculations or experiments. Finally, both results are incorporated into the electroplating simulation program as boundary conditions at the cathode plane. The results of the model showed good agreements with the experimental results, and the effects of fluid flow of electrolytes on the uniformity of deposition thickness was quantitatively predicted.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.688-690
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• 2017

Reduction of breakdown voltage is serious short channel effect (SCE) by shrink of channel length. The SCE occurred in on-state transistor raises limitation of operation range of transistor. The deviation of breakdown voltage for doping concentration is investigated with structural parameters of sub-10 nm double gate (DG) MOSFET in this paper. To analyze this, thermionic and tunneling current are derived from analytical potential distribution, and breakdown voltage is defined as drain voltage when the sum of two currents is $10{\mu}A$. As a result, breakdown voltage increases with increase of doping concentration. Breakdown voltage decreases by reduction of channel length. In order to solve this problem, it is found that silicon and oxide thicknesses should be kept very small. In particular, as contributions of tunneling current increases, breakdown voltage increases.

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.41-45
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• 2018

Two-dimensional (2D) materials have been studied extensively due to their excellent physical, chemical, and electrical properties. Among them, we report the material and device characteristics of tin disulfide ($SnS_2$). To apply $SnS_2$ as a channel layer in a transistor, $SnS_2$ channels were formed by a stripping method and a transfer method. The limitation of this method is that it is difficult to produce uniform device characteristics over a large area. Therefore, we directly deposited $SnS_2$ by atomic layer deposition (ALD) and then performed lithography. This method was able to produce devices with repeatable characteristics over a large area. However, the $SnS_2$ film was damaged by the acetone used as a photoresist (PR) developer during the lithography process, with the electrical properties of mobility of $2.6{\times}10^{-4}cm^2/Vs$, S.S. of 58.1 V/decade, and on/off current ratio of $1.8{\times}10^2$. These results are not suitable for advanced electronic devices. In this study, we analyzed the effect of acetone on $SnS_2$ and studied the device process to prevent such damage. Using polyvinyl alcohol (PVA) as a passivation layer during the lithography process, the electrical characteristics of the $SnS_2$ transistor had $2.11{\times}10^{-3}cm^2/Vs$ of mobility, 11.3 V/decade of S.S, and $2.5{\times}10^3$ of the on/off current ratio, which were 10x improvements to the $SnS_2$ transistor fabricated by the conventional method.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.247-259
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• 2012

The purpose of study is to advance current smartphone research past the limitation it faces being focused primarily on functional performance and to understand the causes of Smartphone diffusion. In order to do this, the dominant design concept was applied in examining the relationship between the determinants of the dominant design and the acceptance of smartphones. The research has yielded results which show that determinants such as technological superiority, number of installed based products, and availability of complementary goods have a positive effect on the intention to use smartphones and the attitude toward its use. Moreover, this study has contributed in broadening the understanding of dominant design by introducing the central concepts of dominant design which are not being dealt with in domestic studies and presenting the major variables which must be considered in the acceptance of smartphones.

• 보존과학연구
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• s.17
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• pp.123-160
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• 1996

There have been many studies and experiments regarding exhibition lighting. Many experiments on photochemical damaging effect and visibility resulted in a practice limited to assigning light levels and adjusting annual exposure time. The three damaging factors to the artifacts are intrinsicsusceptibility to absorb radiant energy, spectral distribution of light source and intensity of illumination and time of exposure. Dividing all the artfacts into three categories to suggest a recommended illuminance level causes some problems. Blue wool, for example, used as the reference material for susceptibility, is not a standard material representing museum artifacts. In the most light sensitive category, ISO class I or anything below have been excluded. The exposure time of one soure can be three times more than another sourece. The spectral distribution of the light source and the relative spectral responsibility of the artifact are not considered in the practice. So in case of very light sensitive material, the recommended illuminance is only the referring value and it is indispensable to check the characteristic of susceptibility of each artifacts. Daylighting is prevailing method to solve the psychological need of the visitors. However, it sould transparent, and should not diffused, and the green-house effect must be considered. llluminance uniformity should based on the maximum illuminance to handle the limitation of exposure for the conservation of a large sensitive object such as a painting. Damage index is not absolute reference for selecting the lighting source because it is experimented from the paper of low grade then calculated. Visibility should be increased by reducing the visual noiseand by planning of appropriate luminance contrast. This paper reviews the problems with the previous studies and experiment sand the current exhibition lighting design practice. The plan for museum showcase lighting is to check the susceptibility and to raise the visibility simultaneously.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.8
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• pp.86-92
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• 2009

In order to minimize ac mutual coupling, the auxiliary electrode are located at a right angle in measuring ground impedance. In case that the measurement space is limited, the alternative method is employed. At that time, it is necessary to investigate the measurement errors due to ac mutual coupling and earth mutual resistance in measuring the ground impedances. 'This paper presents the measurement accuracy according to the location of the current and potential auxiliary electrodes in measuring ground impedance of vertically or horizontally buried ground electrode. The measurement errors due to ac mutual coupling were evaluated Consequently, the effect of ac mutual coupling on the measurement accuracy for horizontally buried ground electrode is greater than that for vertically buried ground electrode. Measurement errors due to ac mutual coupling is the largest when the current and potential auxiliary electrodes are located in parallel. The 61.8[%] rule is inappropriate in measuring ground measurement. Theoretically, in case that the angle between the current and potential auxiliary electrodes is 90$[^{\circ}]$, there is no ac mutual coupling. If it is not possible to route the current and potential auxiliary electrodes at a right angle with limitation of measurement space, the location of these electrodes with an obtuse angle is preferred to that with an acute angle in reducing the measurement errors due to ac mutual coupling.

• Journal of Acupuncture Research
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• v.24 no.1
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• pp.79-98
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• 2007

Objectives : The study of Traditional Korean medical therapy has recently become a popular academic field as proven to be an great alternative to the limitation of Western medical treatment. However, there has been little study examining the Quality of life to investigate the Effectiveness of Recent Traditional Korean Medical Therapy on Treating Allergic Rhinitis. Thus, this study aims to reveal the characteristics of Allergic Rhinitis patients, their clinical symptoms, and other accompanying diseases. Moreover, it attempts to investigate the sense of improvement and satisfaction from the Allergic Rhinitis patients treated with Traditional Korean Medical therapy by examining Quality of Life Questionnaires. Subject and Method : A total of 380 subjects that consists of allergic rhinitis patients and non patients were participated in this study. 330 allergic rhinitis patients were divided into two groups; the experimental group (230 subjects) was treated with Traditional Korean Medical therapy, and the control group (100 subjects) was not treated with any other therapy. Also, the normal control group (50 subjects) who had no symptoms of the allergic rhinitis was participated in this study as well. All the subjects were asked to answer to the questionaries that consist of two parts such as recalling the symptoms that they had 3 month ago, and describing the current symptoms that they had the present. The experimental group also was asked to answer the quality of life questionnaire before and after the therapy. Results: The results of investigating recent Traditional Korean therapy are as follows: 1. The reservoir rate of other disease was 39.0% in the control group and 34.8% in the experimental group. These were higher than the rate of the normal control (10.0%), which reveals the clinical characteristics of allergic rhinitis patients. 2. The symptoms of Allergic Rhinitis showed improvement after Traditional Korean medical therapy, which can be shown by its statistical significance. (p=.000<.001). 3. 97.0% of the Allergic Rhinitis patients treated with the Korean Therapy answered the improvement of symptom within 4 weeks, and 88.3% of the patients were satisfied with the Traditional Korean medical therapy. 4. The Nasal symptoms had prominently positive effect at the most as the symptoms significantly affect sleep disturbances, ocular symptoms, activity limitation, and emotional problems.

• Journal of the Korea Safety Management & Science
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• v.25 no.2
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• pp.71-83
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• 2023

Since last year, the government has enforced the 'Act on the Punishment of Severe Accidents, Etc.' (hereafter referred to as the 'Serious Accident Punishment Act'), which punishes business owners and business managers who fail to fulfill their duty of safety measures with 'imprisonment of one year or more' and the Occupational Safety and Health Act. Based on this, various occupational safety and health policies were developed, including the operation of a system related to entrusting the work of safety managers. Despite these efforts, the effect of implementing the Severe Accident Punishment Act is a groundbreaking change in the current disaster prevention policy, which has increased by 0.02%P and 0.03‱P, respectively, from the previous year to 0.65% of the total accident rate and 1.10‱ of the death rate per 10,000 people as of 2022. As the need emerged, attention was paid to 'collaboration and governance with safety management institutions' in the 'Severe Disaster Reduction Roadmap' announced by the Ministry of Employment and Labor in November 2022. In this study, a meaningful result was derived by comparing and analyzing the industrial accident status of workplaces entrusted by "A" safety management institutions with the national average based on the industrial accident survey table, and the types of industrial accidents that occurred in consigned workplaces were selected as intensive management targets. The policy direction for industrial accident prevention was established. It is necessary to develop safety management work manuals based on the results of this study, expertise, discover best cases of risk assessment and develop guides, and educate and train consigned workers. In addition, it suggests that the government's guidance and supervision are needed to advance the professionalism of safety management entrusted tasks, and that safety management institutions should strengthen their roles and functions for preventing and reducing industrial accidents. However, due to difficulties in disclosing information of specialized safety management institutions, the limitation of the provision, collection, and viewing of research-related data to "A" specialized safety management institutions remains a limitation of the research. It seems likely that more thorough research will be conducted.

• Journal of Internet Computing and Services
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• v.12 no.4
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• pp.61-71
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• 2011

The Smart Network Project is planned for achieving the Internet advanced country by adjusting the Government Future Internet Development as a national agenda. The future Internet is defined as diverse alternative technology and services that can provide optimal services for individual characteristic and situation in anywhere, anytime throughout convergence of communication, broadcasting, and computing to solve the current limitation of the Internet. This paper is to analyze the economic effects of the smart network build-up. For the economic effect analysis, we reclassified the smart network industry classification system and re-drew up 2011 Inter-industry Relations Table by using the Inter-industry Relations Table issued by the Bank of Korea and the RAS techniques. And we analyzed the economic effects that can be drawn from the investment of the smart network industry. As a result, the gross production inductive effect which appears with the economic effect of the smart network establishment project from 2011 to 2015 came out to be about 72 trillion 808.2 billion KW, added value inductive effect of 44 trillion 192.9 billion KW and the employment inductive effect of the job creation of about 412 thousands people. Afterward, it is anticipated that the smart network build-up project to contribute to the improvement of Koreans' daily life. Moreover, this research will be used as a valued basic material in the pursuit of the future network projects.