• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.4
• /
• pp.10-16
• /
• 2007

This paper analyzes the output signal-to-interference-plus-noise ratio (SINR) for a multiple-input-multiple-output (MIMO) multicarrier code division multiple access (MC-CDMA) system with minium mean square error receivers. A previous work of a single antenna MC-CDMA system cannot directly applied to a MIMO MC-CDMA system because some assumptions for single antenna do not match the case of multiple antenna. Therefore this paper expands the concept of freeness to MIMO system by using the Marcenko Pastur law. The analysis shows that the output SINR asymptotically converges to a deterministic value and finds the value on the assumption of freeness. From the analysis, it is easy to calculate bit error rate and the calculation is verified by simulations.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.14 no.6
• /
• pp.1679-1688
• /
• 1990

The method of nonlinear parameter estimation(NPE), which is a statistical and an inverse method, is used to estimate the thermal diffusivity of the porous insulation material. In order to apply the NPE method for measuring the thermal diffusivity, and algorithm for programing suitable to IBM personal computer is established, and is studied the statistical treatment of experimental data and theory of estimation. The experimental data obtained by discrete measurement using a constant heat flux technique are used to find the boundary conditions, initial conditions, and the thermal diffusivity, and then the final values are compared with the values obtained by some different methods. The results are presented as follows:(1) NPE method is used to establish the estimation of the thermal diffusivity and compared results with experimental output shows, that this method can be applicable to define the thermal diffusivity without considering hear flux types. (2) Because of all of the temperatures obtained by the discrete measurement on each steps of time are used to estimate the thermal diffusivity. Although some error in the temperature measurements of temperature are included in estimating process, its influences on the final value are minimzed in NPE method. (3) NPE method can reduce the experimental time including the time of data collecting in a few minutes and can take smaller specimen compared with steady state method. If the tube-type furnace is used, also the adjusting time of surrounding temperature can be reduced.

• Journal of Service Research and Studies
• /
• v.6 no.4
• /
• pp.47-57
• /
• 2016

Open source has an amazing spread with the advent of smartphones. Open-source Moodle in e-learning areas are free of LMS (Learning Management System) and the most widely used worldwide, except for the black board commercial programs. One reason is well designed to support collaborative learning and interaction based on constructivist principles, which is the core principle of e-learning in particular that the theoretical basis of educational technology has a high educational effectiveness and benefits. This study examines the operational practices of collaborative learning using open source learning management system Moodle program. It introduces specific information to support the user of the collaborative learning. It looks at the advantages and singularity of collaborative learning in e-learning through examples shown. The purpose of this study is the importance of the relationship between learners and the importance of self-learning of collaborative learning through collaborative learning in a knowledge repository of Moodle. In addition, collaborative learning outcomes are is based on the motivation of learners and playfulness.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.1
• /
• pp.77-84
• /
• 2014

In this paper, we propose the hierarchical network synchronization scheme that is backward compatible for the existing commercial system, efficient for total system performance, and whose hardware modification is minimized. This system performance is, the relationship among bandwidth efficiency, complexity and MODEM performance, and superiority of network system applicability. The proposed structure can remedy the high hardware complexity and the lower accuracy of network sychronization that the existing satellite communication terminal system in the star network based on TDM/MF-TDMA of DVB-S2/RCS standards has. Besides, It has high efficiency in view of cost and system performance if the system designed for satellite broadcast requires system upgrade. In the body section, its hardware complexity and system performance of the proposed algorithm is analysed theoretically and treated with the related parameters(symbol rate, spreading factor, etc.) and the BER performance of control channel through the computer simulation for its verification that it can be applied for communications system.

• Journal of Science and Technology Studies
• /
• v.1 no.1 s.1
• /
• pp.235-259
• /
• 2001

This study investigates a variety of dysfunctions and dynamics accompanied with the spread of advanced technology, and predicts the developmental directions of future uncertain society. There are, further, proper countermeasures against dysfunctions discussed. First, different theoretical paradigms concerned with the relationship between seience/technology and society would be comparatively analyzed, and their techno-social implications would be examined. Next, the latest trend of bio-technology and information technology, especially the trend of combination of bio- and information technology, appeared in the progress of Human Genome Project, would be considered. Thirdly, techno-social dysfunctions and far-reaching effects following the development of high-technologies would be analyzed, and realistic alternative plans would be suggested. Through this study, we come to a conclusion that, in order to reduce techno-social dysfunctions to a minimum and enhance their eufunctions, not only 'human' control over technological development should be guaranteed, but also action plan for bridging social gaps should be prepared. In addition, fluent communication and mutual understanding of all concerned, particularly between researcher community, government, and civic sector are required.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.27 no.2
• /
• pp.135-149
• /
• 2016

As the public reading campaign has been popular, the book festival, a sociocultural event in relation to the book and reading, becomes a growing public interest. The book festival which could be diversified by each community and its environment would be understood in the perspective of the performance of public library, the diffusion of public reading campaign and the sociocultural togetherness of the community. In that, this study focuses on the book festival of Seongbuk-Gu, Seoul, held in 2015. Specifically, this study looks into the theoretical underpinnings and the background of book festival, examines the case of the '2015 Seongbuk-Gu Book Festival' systematically, and analyzes the factors that influence the book festival, in order to enhance our understanding of the book festival in general.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.9
• /
• pp.799-805
• /
• 2013

An analytical study is conducted to assess the efficiency of a flat-plate solar collector using nanofluids. The nondimensionalized 2D heat diffusion equation is solved by assuming a wavelength-independent extinction coefficient and intensity to obtain the analytical solution of the temperature distribution in the flat-plate solar collector. The dimensionless temperature distribution is investigated as functions of the volume fraction of the nanofluids, magnitude of heat loss, and collector's depth based on the analytical solution when using water-based single-walled carbon nanohorn (SWCNH) nanofluids as a working fluid. Finally, the efficiency of the flat-plate solar collector using the nanofluids is predicted and compared with that of the conventional solar collector. The results indicate that the efficiency of the nanofluid solar collector is better than that of the conventional solar collector under specific geometrical conditions.

• The Journal of the Korea Contents Association
• /
• v.11 no.10
• /
• pp.396-404
• /
• 2011

With increasing of smartphone users various smartphone studies have been carried out. The purpose of this paper is to examine the factors influencing the usage intention of smartphone healthcare application. The influencing factors found from literature reviews on Technology Acceptance Model and the diffusion of innovations theory are user interface design, self-efficacy, innovativeness, and entertainment. Survey is conducted to 220 people in Seoul metropolitan area. The survey results are analyzed regarding the difference for the intention of healthcare application in accordance with respondents' demographic and application usage characteristics. We also examine the difference among four influencing factors by users and non-users. As a result there are significant differences in self-efficacy and innovativeness. This gives some implications to application developers: the system should be easy to use and provide new and useful health contents that can attract early-adopters' attention in order to increase the number of application users.

• The Journal of the Korea Contents Association
• /
• v.20 no.2
• /
• pp.226-239
• /
• 2020

The study seeks to present ways to form and express political opinions while monitoring, regulating and critically accepting the production and distribution of false information and platforms, which are spread channels, through the participation of citizens. First, it logically identified the unfairness of legal regulations on false information. In other words, it is often practically impossible to judge whether false information is false or not, and even false information can sometimes fall within the category of freedom of expression protection. It also revealed that voluntary regulation by platform operators was limited. As an alternative, it was theoretically clear whether civil society should participate in the maintenance and development of democratic public debate sites and create social discourse. The specific method is to find and classify false information and share it with citizens to raise awareness. Second, it forms an autonomous cooperative system with platform operators and others. Third, develop critical media capacity of citizens. Fourth, it responds to producers and platform operators of false information while engaging in community activities as a direct practitioner.

• Journal of Labour Economics
• /
• v.20 no.1
• /
• pp.59-89
• /
• 1997

세계화 추세의 가속, 급속한 기술진보 및 정보화의 확산 등은 국제간의 분업구조 뿐만 아니라 국내의 산업구조 및 취업구조를 급격히 변화시키고 있다. 국내 취업구조의 변화는 산업간 직업간 취업비중을 모두 변화시키고 있어 고용의 양적 측면은 물론이고 질적 측면에서도 큰 변화가 예상된다. 그러므로 중장기적인 노동력수요 예측은 향후 인력양성의 방향과 체계를 결정하는 데 중요한 지표가 될 뿐만 아니라 노동시장 정책에 있어서도 반드시 필요한 자료가 되고 있다. 따라서 본 연구에서는 향후 노동력에 대한 중장기 수요를 일반균형적인 접근을 통하여 산업별 직업별로 예측하고 이 예측결과에 따른 향후 노동시장 및 인력정책의 방향을 제시하는 데 있다. 본 연구에서는 기존의 연구들이 사용한 방법의 이론적 약점을 보완하면서 실증 결과의 예측성을 높일 수 있는 개선된 방법을 사용하였다. 산업별 취업자를 전망하는데 있어 기존 연구결과들은 주로 노동시장의 단일방정식만을 추정함으로써 생산요소의 수요가 비탄력적이지 않음에도 불구하고 생산요소간의 대체가능성을 무시하고 있으며, 인력수요에 중요한 결정 요인인 기술변화를 고려하지 못하고 있거나, 취업계수의 변화를 통해 기술진보의 효과를 고려한다고 하여도 기술진보가 생산요소간에 비중립적(factor non-neutral technology changes)으로 일어날 경우 요소간 대체가능성을 간과하고있다. 이러한 단점을 보완하기 위해 본 연구에서는 산업별 취업자 전망에서 노동시장의 단일방정식 추정이 아닌 일반균형에 입각한 경제 모형을 사용하였다. 또한 직종별 취업자 전망을 위해서는 일반적으로 이용되는 필요 인력량에 대한 고정계수(fixed coefficient manpower requirement)를 추정할 때 이중비례행렬모형(二重比例行列模型)을 이용하여, 산업구조의 변화로 인한 직업별 인력수요 변화가 충분히 고려되도록 하였다. 전망의 결과에 따르면 향후 우리 경제는 지식기반경제(knowledge-based economy)로 이행하고 있다고 볼 수 있다. 우선 산업구조면에서 지식집약적산업으로의 구조조정이 일어나게 되고 이에 따라 산업별 취업구조에서도 고기술산업의 취업준비중이 급속히 증가하게 된다. 직업별 취업분포에 있어서도 전문기술직 행정관리직 등의 고숙련 사무직의 비중은 크게 증가하는 반면 생산관련직과 농림어업직의 비중은 감소하게 된다. 이처럼 경제가 지식집약화되어 감에 따라 고학력자에 대한 수요는 지속적으로 증가하지만 현재 적절한 인력양성과 공급이 이루어지지 않고 있어 향후 기술이나 기능에 따른 수급부일정(需給不一政)(skill mismatch)현상이 매우 심해질 것으로 보인다. 따라서 앞으로의 인력정책에서 가장 주안점을 두어야 할 부분은 첨단기술산업과 관련된 인력의 양성에 있다고 하겠다.