• 대한공업교육학회지
• /
• v.41 no.2
• /
• pp.69-88
• /
• 2016

The study tried to investigate perception of the importance and educational needs of job performance competency of National Competency Standards based vocational education curriculum in technical specialized high schools and meister high schools. For this, the survey was conducted targeting 269 specialty subject teachers in technical specialized high schools and meister high schools. And the results are as follow: First, job performance competency were divided into 5 categories(curriculum guidance, school life guidance, class management, extraordinary activities and administrative duties) and 34 sub-categories. Second, higher importance values were curriculum guidance, extraordinary activities and school life guidance. Higher educational needs values were curriculum guidance, extraordinary activities and administrative duties in categories. Third, higher importance values were construction and reconstruction of NCS learning modules, organization and manage of NCS based vocational education curriculum, guide of the new laws and employment, student records manage, research activities of NCS, hands-on-background training, NCS projects in sub-categories. Fourth, the results show that the NCS experienced teachers more highly evaluated the importance and educational needs of the job performance competency than the NCS inexperienced teachers did.

• Journal of the Korean Data and Information Science Society
• /
• v.23 no.6
• /
• pp.1173-1181
• /
• 2012

In order to suggest the basic resources of mathematics education to the specialized high school, we investigate the attitude of students about mathematics education. Questionnaires survey was carried on 654 students and we use the statistical analysis such as chi-square test, gamma, generalized linear model, Anova, regression. Several result can be derived from the questionnaire analysis. There are differences between the general and specialized high school students in the interest, pre-learning ability etc. The specialized school students think the usefulness of mathematics more importantly, while the general school students think more closely related to their course.

• Journal of the Korea Safety Management & Science
• /
• v.9 no.3
• /
• pp.41-47
• /
• 2007

The purpose of this study is to collect and analyze their opinions to found solutions for reducing safety accidents since it is important to educate the students to recognize the importance of safety. We surveyed 350 students from mechanical and metal engineering departments of an engineering high school located in Seoul, and divided them in two categories and asked them about prevention of safety accidents in laboratories. It is found that further directions and educations are needed for the students as to emergency measures in case of safety accidents. Safety education before laboratory classes is crucial, helpful and effective for prevention of safety accidents. Facility factors that further education is needed for students who don't experiments in orderly manner.

• Journal of the Korean School Mathematics Society
• /
• v.3 no.2
• /
• pp.133-154
• /
• 2000

The purpose of this study is to analyze theoretically suggested performance test and find out the actual conditions is math class at high schools and to suggest some devices for improvement for the various problems. To achieve this goal of study, I applied a performance test to the first graders of high school for one semester, and analyzed various phenomena which appeared during its practice. I made several questionnaire based on the materials of an academic seminar, "Several questions and devices for the improvement on mathematics performance test" And through the analysis, I pointed several problems of the performance test and proposed alternative plans. Several practical alternatives can be suggested for the problems appeared in the operation of performance test. The most important thing than any other technical solution in teachers′ diverse endeavor and enthusiastic research attitude to overcome the difficulties. Teachers′ spontaneousness is the foundation to enhance their own specialty and eradicate the propriety of the performance test.

• Journal of the Microelectronics and Packaging Society
• /
• v.26 no.4
• /
• pp.15-22
• /
• 2019

Metallic nanowires (MNWs) have recently been considered as one of the most promising candidates for flexible electrodes of advanced electronics including wearable devices, electronic skins, and soft robotics, since they have high aspect ratio in physical shape, low percolation threshold, high ductility and optical transparency. Herein, we review the latest findings related to the MNWs and discuss the properties and potentials of this material that can be used in implementation of various advanced electronic devices.

• Journal of Power Electronics
• /
• v.7 no.3
• /
• pp.203-212
• /
• 2007

In this paper, a proposed approach to improve the power factor of three-phase rectifiers and to stabilize the output voltage against load change is presented. The elements of the given control strategy are small size, low cost, high performance, and simplicity. The proposed control strategy of switches is based on a prototype of three bi-directional switched consisting of four diodes and one IGBT. A control technique and operational procedure are also developed, both theoretically and experimentally. The experimental results clearly verify the theoretical analysis from the prototype connected to grid unity.

• Journal of the Korea Society of Computer and Information
• /
• v.23 no.11
• /
• pp.75-84
• /
• 2018

Social engineering attack means to get information of Social engineering attack means to get information of opponent without technical attack or to induce opponent to provide information directly. In particular, social engineering does not approach opponents through technical attacks, so it is difficult to prevent all attacks with high-tech security equipment. Each company plans employee education and social training as a countermeasure to prevent social engineering. However, it is difficult for a security officer to obtain a practical education(training) effect, and it is also difficult to measure it visually. Therefore, to measure the social engineering threat, we use the results of social engineering training result to calculate the risk by system asset and propose a attack graph based probability. The security officer uses the results of social engineering training to analyze the security threats by asset and suggests a framework for quick security response. Through the framework presented in this paper, we measure the qualitative social engineering threats, collect system asset information, and calculate the asset risk to generate probability based attack graphs. As a result, the security officer can graphically monitor the degree of vulnerability of the asset's authority system, asset information and preferences along with social engineering training results. It aims to make it practical for companies to utilize as a key indicator for establishing a systematic security strategy in the enterprise.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.23 no.3
• /
• pp.153-160
• /
• 2018

Recent trends in high-power-density applications have highlighted the importance of designing power converters with high-frequency operation. However, conventional LLC resonant converters present limitations in terms of high-frequency driving due to switching losses during the turn-off period. Switching losses are caused by the overlap of the voltage and current during this period, and can be decreased by reducing the switch voltage. In turn, the switch voltage can be reduced through a series connection of four switches, and additional circuitry is essential for balancing the voltage of each switch. In this work, a three-level LLC resonant converter that can operate at high frequency is proposed by reducing switch losses and balancing the voltages of all switches with only one capacitor. The voltage-balancing principle of the proposed circuit can be extended to n-level converters, which further reduces the switch voltage stress. As a result, the proposed circuit is applicable to high-input applications. To confirm the validity of the proposed circuit, theoretical analysis and experimental verification results from a 350 W-rated prototype are presented.

• Journal of Environmental Science International
• /
• v.19 no.12
• /
• pp.1343-1354
• /
• 2010

The purpose of the study was to analyze the persistence of HCH in atmosphere, soil, sediment and water of the western and southern regions of Korea. The samples from the western region were collected from Anmyeon Island, and the samples from the southern region were collected from Kimhae and Busan. The concentration of HCH isomers in atmosphere showed the pattern of $\alpha$-HCH>$\gamma$-HCH>$\beta$-HCH. The regions with high HCH concentration in the atmosphere are the regions that have been highly exposed to HCH used in the past, and the areas that have been influenced by the long range transport. The HCH that persists in the soil, water and sediment evaporates into the atmosphere, showing the characteristics of Air-Surface exchange. When the regional concentration distributions are compared, the concentration of HCH was higher in the atmosphere of a plain and the cities near the plain, than the urban areas. In this study, the ratio of $\alpha/\beta$-HCH was used as an indicator for estimating the source of Technical HCH and Lindane. According to the result, the contribution of Lindane was high in Kimhae plain and Kimhae urban areas. However, in Busan, the contribution of Technical HCH was higher than Lindane. In case of Anmyeon Island, the western region of Korea had high contribution from Tehcnical HCH. In soil and sediment, $\beta$-HCH was dominant. In water, $\gamma$-HCH was dominant among other isomers. Such results are due to $\gamma$-HCH inLindane. Furthermore, the source of $\gamma$-HCH in urban areas is assumed to be the use of medicine, medical supplies and other living supplies. Based on the results of this study, the management of HCH, a newly list up emerging POPs, should be strengthened by further research on sources, fate, persistency, accumulation and exposures and etc. to the risk assessments.

• Fire Science and Engineering
• /
• v.20 no.3 s.63
• /
• pp.107-112
• /
• 2006

The purpose of this study is to help the education of fire safety of technical high schools through the investigation of skills club students's recognition on fire safety in Seoul city. To achieve the purpose, 56 skills students who going to skills competition were surveyed for 3days from Jun. 19 to 21, 2006. The Results of this study are as follows ; First, a large numbers of students in technical high school placed low value on the importance of safety in life, and fire safety was very important, however, lower than structural safety. Second, the education of fire safety was arranged by school authorities, carried out only by the half of these school. It was necessary that the specific education of fire safety for major and skills competition was hosted by a department. Third, it was necessary that the system all accidents were certainly reported by the related student and the method prevented a recurrence. 4th, the field of fire safety in Industrial Introduction subject of national curriculum was satisfied by students. And if this subject revised, students wanted to extend the contents of fire safety and to orient to practical technique.