• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.1
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• pp.39-47
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• 2005

The range of hardware implementation increases in communication systems as high-speed processing is required for high data rate. In the broadband wireless access (BWA) system based on IEEE standard 802.16 the functions of higher part in the MAC layer to Provide data needed for generating MAC PDU are implemented in software, and the tasks from formatting MAC PDUs by using those data to transmitting the messages in a modem are implemented in hardware. In this paper, the interface hardware for efficient message exchange between MAC and PHY layers in the BWA system is designed. The hardware performs the following functions including those of the transmission convergence(TC) sublayer; (1) formatting TC PDU(Protocol data unit) from/to MAC PDU, (2) Reed-solomon(RS) encoding/decoding, and (3) resolving DL MAP and UL MAP, so that it controls transmission slot and uplink and downlink traffic according to the modulation scheme of burst profile. Also, it provides various control signal for PHY modem. In addition, the truncated binary exponential backoff (TBEB) algorithm is implemented in a subscriber station to avoid collision on contention-based transmission of messages. The VLSI architecture performing all these functions is implemented and verified in VHDL.

• The Journal of Society for e-Business Studies
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• v.23 no.1
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• pp.1-22
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• 2018

The value chain has been utilized as a strategic tool to improve competitive advantage, mainly at the enterprise level and at the industrial level. However, in order to conduct value chain analysis at the enterprise level, the client companies of the parent company should be classified according to whether they belong to it's value chain. The establishment of a value chain for a single company can be performed smoothly by experts, but it takes a lot of cost and time to build one which consists of multiple companies. Thus, this study proposes a model that automatically classifies the companies that form a value chain based on actual transaction data. A total of 19 transaction attribute variables were extracted from the transaction data and processed into the form of input data for machine learning method. The proposed model was constructed using the Random Forest algorithm. The experiment was conducted on a automobile parts company. The experimental results demonstrate that the proposed model can classify the client companies of the parent company automatically with 92% of accuracy, 76% of F1-score and 94% of AUC. Also, the empirical study confirm that a few transaction attributes such as transaction concentration, transaction amount and total sales per customer are the main characteristics representing the companies that form a value chain.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.423-435
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• 2010

The number of professionals in the science and engineering fields decreases all over the world. Especially in Korea, the declining rate of both the laborable and economically active population, aging of the population at the fastest level, and the declining birth rate make it tougher to secure the core brains of the future. After speculation of all programs above, some common factors have been derived and every program appeared to have the support for each level of inducing, caring, and utilizing. And the means of support could be categorized into the financial, legal, and social aspects. Lastly, a logical tool called Systems Thinking has been applied to the FLS Conditions and the Brain Internalization Process to assure the efficacy and applicability of the models. This is to minimize any de facto side effects by analyzing all 'feedback loops' stemming from the models. And the 'causal loop diagrams' have been utilized to come with the complementary measures. Such series of verification could convince the virtue of the models. Governments and universities can make use of the FLS Conditions and the Brain Internalization Process so the policies or plans about the foreign brains can be built in a uniformized and consistent framework. I hope, as a result, the international competency of Korea to induce and utilize the foreign brains be raised with the constant and standardized formality.

• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.76-86
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• 2016

Recently, the Contracts of International Construction Business has been decreased from the beginning of 2015 in Korea, although it has been steadily increased until 2014. This trend could be caused by Low-Price Contracts, the lack of Know-how and experience in operating, the poor management of Claims and Low-Profitability in Business. It has been recognized that the qualitative improvement of Business Contacts are necessary for successful Projects. In the Bidding Process, therefore, Experience data as In-House Data and Lessons Learned for projects should be strategically involved to assure riskless offers. Accordingly the Proposal Process are needed to be organized and enhanced by including processes for risks review about technical, marketing and commercial part during the bidding. This paper proposes a Risk Management Process model during Bidding Phase, using Risk Evaluation Method through the project life-cycle. The Concept of Model is to define CSF (Critical Success Factor) in the bidding process and Risk Factors are linked to CSF and Organization based on RAM (Responsibility assignment matrix).

• Journal of The Korean Association For Science Education
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• v.24 no.3
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• pp.532-543
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• 2004

The teacher appointment examination is consisted of a written test, an interview, a demonstration of teaching practices, one's academic record etc. The primary written test(full credit of 100) consists of multiple-choice test of general pedagogy(30%) and constructed response test of science(70%). The science test consists of science education($20{\sim}30%$) and science content($70{\sim}80%$). Five science exams were implemented for appointing general science, physics, chemistry, biology and earth science teachers in 2002 and 2003. The credits alloted to science education domain decreased from $25.7{\sim}30%$ in 2002 to $24.3{\sim}25.7%$ in 2003. The percentage of correct answer was similar between science education and science content domain in 2002, but the percentage of correct answer in science education domain(70.2%) was 29.8% higher than that of science content domain in 2003. Earth science exam almost reached the target mean score of 60 but the other four exams showed the mean scores ranging from 45.0 to 52.7 in 2002 and from 40.1 to 49.6 in 2003. The percentage of high difficulty items(p<40%) was 41.2% in physics and chemistry in 2002, 50% in physics and chemistry, and 45% in biology in 2003. Seventy eight percent of the items showed fairly high discrimination index(r>.30). In addition, the reliabilities of 5 tests were from .79 to .88. In conclusion, it is recommended that the credits alloted to science education domain should be increased up to 30%, and exam difficulties should be lowered to a proper level by making science content items easier.