• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.8
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• pp.1421-1432
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• 1994

The optimum design and performance of noncoherent TDL considering the effect of distortions due to the IF bandpasss filters are described. NRZ data and ideal filter is presumed in the simulation. The optimum filter bandwidth is calculated in the sense of minimizing the loop's squaring loss, which is equivalent to minimizing the loop's tracking jitter for a given data rate and data signal-to-noise ratio. As a result, the optimum filter bandwidth depends on the signal-to-noise ratio, and is obtained in the range of about 1-2 times of the data rate.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.60
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• pp.195-209
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• 2013

South Korea, despite the financial turbulences has marked the trade volume of USD 1 trillion and marked $7^{th}$ largest exporter in 2013. Approximately 40% of the entire import of Korea was for export. In the South Korean trade structure, import and export are closely related, requiring proactive import financial assistance policies. Recognizing this, K-sure has made import insurance policy available on the market since July 2010. The K-sure insurance policy targets both financial institutions and importers. This is the reason why this research seeks to review the import insurance terms for importers and compare with foreign import insurance products to find out ways to improve. K-sure's import insurance for importers is to cover a loss of a policyholder when the policyholder or importer domestically addressed made a prepayment but cannot receive goods. The import insurance is applied to import transactions of goods or resources. K-sure's import insurance coverage needs to be expanded to intermediary trade and consignment processing trade, etc. In this sense, a more systematic educational program should be introduced about K-sure's import insurance.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.451-453
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• 1995

This paper examines characteristics of the accounting rate system whereby international telecommunications carriers settle net balances of account arising from bilateral traffic flows. Using a two stage game model, we explain problems in the system: growing traffic and payment imbalances, and resulting conflicts regarding accounting rates between carriers of, say, developed and developing countries. In this paper, we view the problems as a splitting-a-pie game in which one carrier cannot get more without a loss of the other, but total pie size depends upon the accounting rate. Therefore, a natural solution should be inevitably of a Coasian-type to establish a mutual agreement. In this regard, we first derive an efficient accounting rate, in the sense that it can make both carriers better off. Next we suggest some ways of attaining the efficient outcome. Regulatory and policy implications are also discussed.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.197-201
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• 1988

A reliable Analytical Redundancy(AR) based Fault Detection Scheme(FDS) that can detect, discriminate sensor fault and process fault is presented. And a Fault Tolerant Control System ( FTCS ) with the FDS that performs original control objective without considerable loss of control performance in the face of sensor/process faults is constructed. These propositions are valuable in the sense that it resolves the well known sensitivity problem and that sensor/process faults can be detected, discriminated so that effects of any fault can be promptly accomodated by reconfiguring control system structure automatically.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.57.1-57
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• 2001

The objectives of congestion control in ATM (Asynchronous Transfer Mode) networks are maximum utilization of network resources, acceptable level of low cell loss and fairness among all VCs (Virtual Connections). In this paper, we present a congestion control algorithm which is based on state space model, The proposed controller uses optimal control algorithms (LQR, Mixed-LQR), where control parameters can be designed to ensure the stability of the control loop in a control theoretic sense, over the propagation delay. We show how the control mechanism can be used to design a controller to support ABR service based on feedback of explicit rates. Simulation results are presented to substantiate our claim.

• Communications for Statistical Applications and Methods
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• v.7 no.2
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• pp.617-631
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• 2000

This paper is concerned with suggesting a Bayesian method for variable selection in generalized logit model. It is based on Laplace-Metropolis algorithm intended to propose a simple method for estimating the marginal likelihood of the model. The algorithm then leads to a criterion for the selection of variables. The criterion is to find a subset of variables that maximizes the marginal likelihood of the model and it is seen to be a Bayes rule in a sense that it minimizes the risk of the variable selection under 0-1 loss function. Based upon two examples, the suggested method is illustrated and compared with existing frequentist methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.4
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• pp.475-490
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• 2010

Cognitive Radio is an advanced enabling technology for the efficient utilization of vacant spectrum due to its ability to sense the spectrum environment. It is important to determine accurate spectrum utilization of the primary system in a cognitive radio environment. In order to define the spectrum utilization state, many CR systems use what is known as the quiet period (QP) method. However, even when using a QP, interference can occur. This causes reduced system throughput and contrary to the basic condition of cognitive radio. In order to reduce the interference time, a frequency-hopping algorithm is proposed here. Additionally, to complement the loss of throughput in the FH, a HMM-based channel prediction algorithm and a channel allocation algorithm is proposed. Simulations were conducted while varying several parameters. The findings show that the proposed algorithm outperforms conventional channel allocation algorithms.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.473-477
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• 2008

In this paper, we introduce the positioning methods using the grid sensor network. The basic operational principle of grid sensor network can be the wireless communication using the sensor node attached on the objects. Sink node receives the environmental information (e.g., temperature, humidity and so on), and transmits the information to the core database. Since the grid sensor network basically uses wireless communication, it is necessary to observe the place where grid sensor nodes to be installed. In this sense, we carried out the practical measurement on the wireless propagation in an applicable field. In addition, link budget study and SNR estimation works were done in accordance with the results from the measurement.

• Korean Journal of Human Ecology
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• v.19 no.6
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• pp.1063-1070
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• 2010

This study examined 12 types of towels with differing fabric material, function, quality, printing, pile length, twist, etc. from a towel company which manufactures and distributes products domestically. After 3 months of use by consumers, a consumer satisfaction survey was administered and results analyzed. Four types of towels were assigned to each group and the towels were used every day for 3 months. Participant feelings after using the towel for the first time and after using it for three months were investigated. The questionnaire consisted of 26 questions on a 5-point Licket-type scale. The first 13 questions measured perceptions of absorption, touch, fine fiber loss, contamination, deformation, drying speed, and design. Other questions compared differences between the two towel types in terms of their material, function, quality, printing, pile length, and degree of twisting. Results showed that, with regards to weight, consumers preferred towels between 130~150g and a thickness of around 1.7~1.8mm. The bamboo towel was considered superior to the cotton towel in terms of sense of touch and did not happen linter after washing. The antibacterial towel was considered better than the cotton towel in terms of absorption but in terms of contamination, participants felt the antibacterial towel became dirty more easily than the cotton towel. We thought that it might be influence of the color of towel. Low-quality towels became stiffer and misshapen more easily than higher-quality towels. But the study showed that the consumers did not perceive significant differences in the towels' quality. Printed towels became thinner and their color changed more with washing. The consumers preferred the design of jacquard towels to printed towels. Towels with short piles was happened more linter than the towel with long pile after washing. Non-twisted towel were better than the highly-twisted towel in terms of sense of touch and absorption but the non-twisted towel happened more linter after washing and became dirty more easily.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.679-687
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• 2013

Currently, we are living in the era of digital media that puts the technologies in front which is called digital. Based on the characteristic of 'de-materialistic', human senses have been extended more than ever and there is no exception on those influences. Even though the existence of media seriously brought the identity and value of the painting into a question after the emergence of analog photos, advent of digital photos are raising the wind of new paradigms and values creation more seriously than ever. Unlike analog photos of the past which go through chemical process, true nature of digital photo goes through the digital process which is represented by 0 and 1. This didn't bring the loss of the original, but rather brought the creation of the copy which excels the original through retouching and consequently, destroyed the traditional value which is referred as an original. Like this, digital photo image has aesthetics and value of existence which is differentiated from analog photo because it has essentially different structures and characteristics with analog photo.