• 한국신재생에너지학회:학술대회논문집
• /
• 2006.06a
• /
• pp.551-554
• /
• 2006

An inverter system which consists of three bi-directional buck-boost converters, is proposed for motor driving. Three phase sinusoidal output voltages can be generated by utilizing three buck-boost converters. The advantage of this scheme is that it does not require a separate DC-DC converter for motor driving, i.e. inverter function is combined into the three DC-DC converters. This topology is suitable for inverters for hybrid or fuel cell vehicles where DC link voltage is subject to change depending upon charging status or output power. So the proposed system is capable of driving motor at high speed. The converter system is controlled by PI controller and simulation results done by MATLAB SIMULINK are provided.Ҙ?⨀ሉȀ̀㘰々K䍄乍?ጊ츀Ѐ㔹〻Ԁ䭃䑎䴀

• The Journal of Korean Society for School & Community Health Education
• /
• v.1 no.1
• /
• pp.95-106
• /
• 2000

The purpose of this study was to be of use for the preparation of more desirable sex education system at elementary school, by making content analysis of the current textbooks related to sex education and surveying what opinions the persons concerned had about it. The purpose of this study were as follows; Elementary school textbooks were analyzed to find out what kind of sex education was included in them. And questionnaires on how to improve school sex education content were prepared, by which 207 male and female teachers were surveyed in the city of Paju and Koyang, Kyonggi province. The conclusions were as follows; 1. Content Analysis of Textbook Sex Education The content related to sex education was relatively much included in textbooks of the right life, morality and physical education. Although morality was a subject to be instructed for the third-grade students or older, elementary school students virtually received sex education from the first grade, as the right life and the joyful life were a subject for the lower-grade students, and this met the goal of sex education or the need of the times. However, sex education content leaned heavily toward family, family life or parental love. There was no mutual complement among subjects, and no link among grades, either. 2. Teacher Opinion on Sex Education Content for Each Grade When the subjects were asked about if sex education content was appropriate for each grade, they answered 20 items should be more emphasized and 6 items might be left out. And there were 6 items regarded by them as one that should be rearranged in consideration of grade. 3. The Ideal Opinion of Sex Education Content The following model could be recommended for elementary school sex education, which was designed to meet the objectives of school sex education as much as possible and to offer a systematic link among grades, based on the findings by textbook analysis and Questionnaire survey, and on elementary school sex education materials recommended by the Ministry of Education: The content selected for the first grade of elementary school was my body, cleanness of genitals, male-female cooperation, and family cooperation. For the second grade, the selected content was male-female physical difference, male female psychological difference, parental and I(origin of a birth). For the third grade, the selected things were important a body(cleanness of genitals), birth of a life, and male-female comprehension and cooperation. For the fourth grade, the selected things were physical development, management of genitals, physiology and management of menstruation, propagation and growth of organism, concern for the other sex, comprehension of and cooperation with the other sex, and prevention of sexual violence. Four the fifth grade, the selected things were secondary sex characteristic, physiology and management of menstruation, operation for phimosis, understanding of seminal emission, structure and function of the genital organs, birth and growth of a baby, television/sex information, and mass communications/sex information. For the sixth grade, the selected things were secondary sex characteristic, understanding of seminal emission, male-female cooperation, male and female role, male-female manners, mass communications/sex information, family and family life. Finally, what should be taught in sex education must be studied constantly, as it should be revised or supplemented periodically, according to student's sexual maturity or social, cultural changes.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.631-637
• /
• 2005

This paper presents a stiffness analysis method for a low-DOF parallel manipulator, which takes into account of elastic deformations of joints and links. A low-DOF parallel manipulator is defined as a spatial parallel manipulator which has less than six degrees of freedom. Differently from the case of a 6-DOF parallel manipulator, the serial chains in a low-DOF parallel manipulator are subject to constraint forces as well as actuation forces. The reaction forces due to actuations and constraints in each limb can be determined by making use of the theory of reciprocal screws. It is shown that the stiffness model of an F-DOF parallel manipulator consists of F springs related to the reciprocal screws of actuations and 6-F springs related to the reciprocal screws of constraints, which connect the moving platform to the fixed base in parallel. The $6{times}6$ stiffness matrix is derived, which is the sum of the stiffness matrices of actuations and constraints. The six spring constants can be precisely determined by modeling the compliance of joints and links in a serial chain as follows; the link can be considered as an Euler beam and the stiffness matrix of rotational or prismatic joint can be modeled as a $6{times}6$ diagonal matrix, where one diagonal element about the rotation axis or along the sliding direction is zero. By summing the elastic deformations in joints and links, the compliance matrix of a serial chain is obtained. Finally, applying the reciprocal screws to the compliance matrix of a serial chain, the compliance values of springs can be determined. As an example of explaining the procedure, the stiffness of the Tricept parallel manipulator has been analyzed.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.29 no.5
• /
• pp.1063-1075
• /
• 2019

In recent years, industrial automation has been established and WISN (Wireless Industrial Sensor Network) has been introduced for efficient system management. By introducing WISN, many engineering costs have been reduced and process processors have been optimized. And communication flow using wireless is increasing. An empirical study on industrial wireless sensor networks is actively conducted, but there are few security studies on them and they are exposed to such threats. If there is a problem with the standard of the wireless communication protocol itself, the device that is certified according to the standard may also be subject to security threats including problems. We analyze security functions and threats of ISA 100.11a and WirelessHART protocol stack based on standards. Procedures for distributing the security key are not provided or it is vulnerable using the Global Data Link key when the device enters the network. This paper presents the problems of the standard itself and presents the security requirements accordingly.

• Korean Institute of Interior Design Journal
• /
• no.12
• /
• pp.40-49
• /
• 1997

What's the direction of INTERIOR ARCHITECTURAL DESIGN in 21 Century High Tech\ulcorner The purpose of this research is to show not only practical use of Computer Graphic(CG) as simple tool function, but offering conversation with computer and other ways of method. When we consider poor CG market, investment on the research of VR(Virtual Reality) is the most urgent. The investment on VR will solve various problems. Firstly. It will solve the problems drived from Interior design process by making spatial images like reality. Secondly, It will solve high wages and financial difficulties caused by raise cost funds. Thirdly, It prevents in a road from foreign company that will bring enormous program, caused by opening the domestic market. Also, It help interior designer check in advance the problems in constructure through showing him a supposed imagination including the system and location of equipments. But it is reality that even ordinary American can't offer VR(Virtual Reality) System. We should have noted that it is normal to spend 10 billion won for such presentation as Model House in the large corporation. We must acknowledge that it is such a waist of money nationally. Therefore, investment on CG & VR System is essential in order to save cost more effective presentation & interior design. We will see great result within a year. As we can see, there is huge area we have make develop. One of them is specific technical plan on VR System and study of flow chart. We close with simple methodological way to use VR System and will study Computer System. Which is fitting to CG that we have to solve the link of hardware and software on VR System\ulcorner We know from the cases in other countries that continuous research on this subject has great value for Interior Architectural Design and its effective use. When we try hard not only for methodological use but practical use, the purpose of CG and VR System will be a factor to contribute on this subject for better Interior design & presentation.

• Korean Institute of Interior Design Journal
• /
• v.24 no.1
• /
• pp.160-168
• /
• 2015

The subject of this research is to analyze the design characteristics of outdoor spaces in Good Design awarded apartment complexes in the past decade. The results are as follows. First, the overall outdoor space design theme, one of the conceptual elements, is focused on both 'nature' and 'story of various subject' that are similar to each other. Second, the case study object with the visual openness, which is secured between apartment blocks, is shown frequently in case box-shaped apartment blocks are arranged in a row. However, in case of Y-shaped block arrangement, the visual openness secured within an apartment complex is considered more important. Third, according to the result of circulation/ inner path element, the most frequently appeared inner path form is a grid pattern with straight path emphasis. While apartment complexes with the parking lot on the ground are only 3 out of 18 cases, it with circulation path for vehicle on the ground level are over 61%. Fourthly, the design characteristic of social space of physical outdoor design appears to be 'central link facility type'. In this case, the central community facilities are more likely to be combined with various functions, such as green, water, and social connection. Fifthly, in case of natural space, most of the apartment cases are shown over 45% green area ratio with wide green and water space provision. Especially, the differentiation is to provide the space where can stimulate a resident's participation.

• Journal of the Korean Society for information Management
• /
• v.24 no.4
• /
• pp.73-96
• /
• 2007

In this study, the characteristics of scholarly communication through the Web and scientific journals are explored, and scholarly communication patterns in two scientific disciplines are compared to reveal the difference. Economics and Computer Science-Information Systems are selected as two disciplines to be analyzed. In the data collection process, 10 keywords are extracted from a database for each subject field, and scholarly Web pages and journal articles related to these keywords are collected and analyzed. Our investigation includes the characteristics of scholarly Web pages, Multi-Dimensional Scaling (MDS) analysis of co-linked Web pages as well as co-cited journal articles, and changes in the scholarly communication activities occurring on the Web and in scientific journals respectively over time. We found certain differences as well as common features in scholarly communication patterns between the Web and scientific journals for both fields of Economics and Computer Science. We also found that scholarly communication occurring on the Web displays unique features for each subtopic within the same field of study.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.9
• /
• pp.1933-1940
• /
• 1997

The development of CMOS IC chip and external system with optical transmission sytem is proposed in this paper, which deal with 4 subject 4 channel biological signals, receive and transmit biological signals to the external system using LED and infrared light of photodiode. This system decreases the dependency of power supply voltage to the COMS IC chip. A newenforce synchronization technique using infrared bi-directional communication has ben proposed. The telemetner IC with the size of $5.1{\times}5.1mm^2$ has the followingfunctions:receiving of command signal, initialization of internal state of all functional blocks, decoding of subject selection signal, time division multiplexing of 4-channel modulated biological signals, transmission of modulated signals to external system, and auto power down control. To confirm the total telemetry system, electrocardogram is transmitted and received to the external system using optical link.

• Management & Information Systems Review
• /
• v.31 no.4
• /
• pp.83-108
• /
• 2012

College students show keen interest in advertising contest, and some contests link with class so that students participate the contest as a class assignment. But the interest is not just limited to students but to businesses. Until now five studies was made on this subject, and major findings of those dissertations are given to activating contest participation, corporate ethics and industrial-educational cooperation. It seems not enough to explain the over-heated phenomenon with the results, so that more research should be made on advertising contest. Required studies with this subject are analyzing the effectiveness relating between investment and result, theoretical establishment by empirical approach, comparative study depending on the style of contest, casual relationship between personal character and image of corporate hosting contest and so on.

• Journal of The Korean Association of Information Education
• /
• v.26 no.5
• /
• pp.457-465
• /
• 2022

The government has proposed various policies to 'extend the time for teaching information education in elementary schools'. However, in the 2022 revised practical arts (technical·home economics) curriculum, information education is still organized for only 17 hours the same as before, and there is not enough connection with the middle school information subject. In this study, policies related to information education in elementary schools such as National Strategy of Artificial Intelligence, Comprehensive Plan of Information Education, Education Policy Direction and Core Tasks in the Artificial Intelligence Era, and Digital Talent Education Plan were analyzed. In addition, after the '2022 revised national curriculum guidelines' was announced in 2021, the problems of the practical arts curriculum were analyzed by analyzing materials of the draft proposal of the curriculum and comments posted on the Public Participation Communication Channel. Finally, I suggested a plan to link the 2022 revised practical arts (technology·home economic) curriculum to the information subject of middle school in detail, and to expand information education in elementary schools.