• IE interfaces
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• v.13 no.4
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• pp.619-626
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• 2000

In this paper, we place the focus on suggesting a method of forecasting demand for PCS resale service with survey data in Korea. It is important for the service provider to forecast the diffusion process when designing marketing strategies and analyzing the costs and benefits. For the reason, we conduct a survey of three groups composed of non-subscribers, cellular subscribers, and PCS subscribers in order to forecast the demand according to several possible scenarios and business strategies. We consider the survey item that is measured by multiple point scales in response to a question if he would subscribe to the mobile telephone service in the future. We propose a method to forecast the size of market potential by classifying each individual into the two extreme groups, that is, yes or no. Then, by integrating survey data and historical data, we forecast the demand for PCS resale service that varies according to scenarios and strategies. From the results, we can find several implications for the provider of PCS resale service.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.241-250
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• 2000

Chua's circuit is a simple electronic network which exhibits a variety of bifurcation and attractors. The circuit consists of two capacitors, an inductor, a linear resistor, and a nonlinear resistor. In this paper, a transmitter and a receiver using two identical Chua's circuits are proposed and synchronizations and secure communication of a lossy equivalent transmission are investigated. Since the synchronization of the lossy equivalent transmission system is impossible by coupled synchronization, theory having both the drive-response and the coupled synchronization is proposed. The proposed method is synthesizing the desired information with the chaos circuit by adding the information signal to the chaos signal in the lossy equivalent transmission system.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.9
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• pp.417-422
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• 2002

ZnO thin films were deposited on various substrates, such as Si-(111), SiO$_2$(5000 $\AA$ by thermal CVD)/Si-(100), and SiO$_2$(2000 $\AA$ by RF sputtering)/Si-(100). The (002)-orientation, surface morphology and roughness, and electrical resistivity of deposited films were measured and compared in terms of substrate. Surface acoustic wave(SAW) filters with a multilayered configuration of IDT/ZnO/SiO$_2$/Si were also fabricated and the IDT was obtained using a lift-off method. From the frequency-response characteristics of fabricated devices, the insertion loss and side-lobe rejection were estimated. The experimental results showed that the (002)-oriented growth nature of ZnO films, which played a crucial role of determining the characteristic of SAW device, was strong1y dependent upon the SiO$_2$buffer.

• The Transactions of the Korea Information Processing Society
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• v.7 no.3
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• pp.776-787
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• 2000

Write requests which stored in disk cache of the RAID5 controller should be destaged to disk arrays according to the destage algorithm. As the response performance of the parallel IO request is being hit by the effect of the destage, several destage algorithms have been studied to enhance the performance of he RAID5 controller. Among the destage algorithms, the load balancing destage algorithm has better performance than other destage algorithms when system load is highly increased. But the load balancing destage algorithm gives priority to load balance among the disks in disk arrays, therefore, when some disks are affected by the very heavy system load caused by small data requests, the load balancing destage algorithm cannot enhance the performance of parallel IO requests effectively since it makes effort to maintain the load balance without the benefit of the locality of the write requests. This paper proposes a new RAID5 controller that applied reference-load balancing destage algorithm which decides the destage priority based on the reference history and load distribution of the disks. The simulation results show that RAID5 controller with the reference-load balancing destage algorithm has better performance than previous load balancing destage algorithm.

• The Transactions of the Korea Information Processing Society
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• v.7 no.2
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• pp.411-425
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• 2000

Information retrieval systems for structured documents which are written in SGML or XML support partial retrieval of document. In order to efficiently process queries based on document structures, low memory overhead for indexing, quick response time for queries, supports to powerful types of user queries, and minimal updates of index structure for document updates are required. This paper suggests the Global Document Instance Tree(GDIT) and proposes an effective indexing scheme and query processing algorithms based on the GDIT. The indexing scheme keeps up indexing and retrieval effciency and also guarantees minimal updates of the index structure when document structures are updated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05a
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• pp.5-12
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• 2000

본 연구에서, Daubechies'Mother Wavelet를 이용한 이산 웨이블렛 변환(Discrete Wavelet Transform)에 기초한 새롭고 효과적인 특정추출방법을 제안하였다. 특정추출을 이용하여 응용방향을 설명하고 또는 통계적 파라메터의 평가를 행하였다. 본 연구에서는 다음과 같은 몇 가지 사실을 알 수 있었다. 1. 시스템에서 발생된 (인가전압이 0[V]) 노이즈라 볼 수 가있는 렌덤노이즈(Random Noise)를 디지털필터인 FIR(Finite Impulse Response)필터를 통하여 상당한 노이즈를 억제할 수가 있었다. 2. 이산 웨이블렛 변환 시 레벨 1~4까지 변환한 결과 최적의 변환상태 Level-3을 기준으로 하였다. 3. 특정추출 파라메터는 음향방출신호의 최대값, 평균값, 분산, 왜도, 첨쇄도를 특정추출파라메터로 이용하였다. 4. 특정추출 결과를 이용하여 전체 열화시간 중 대표적 음향방출신호 중 초기열화신호, 중기열화신호, 말기열화신호를 얻을 수 있었다. 이런 특정추출을 통하여 변압기열화상태를 진단할 수 있는 가능성을 확인 할 수가 있었다.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.52-55
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• 2000

Structually organized mono- and multilayers were developed on gold for the catalytic and affinity biosensing using hyper-branched dendrimers. For the catalytic biosensing interface, a new approach to construct a multilayered enzyme film on the electrode surface was developed. The film was prepared by layer-by-layer depositions of dendrimers and periodate-oxidized glucose oxidase. The voltammograms obtained from the GOx/dendrimer multilayered electrodes revealed that bioelectrocatalytic response is directly correlated to the number of deposited bilayers. From the analysis of voltammetric and ellipsometric signals, the coverage of active enzyme per layer during the layering steps was estimated, demonstrating the spatially-ordered multilayer formation. As an extension of the study, dendrimers having various degrees of ferrocenyl modification were prepared and used. The resulting electrodes were electrochemically characterized, and the density of ferrocenyl groups, active enzyme coverage, and sensitivity were estimated. For the affinity-sensing surrface, a biosensor system based on avidin-biotin interaction was developed. As the building block of affinity monolayer, G4 dendrimer having partial ferrocenyl-tethered surface groups was prepared and used. And the biotinylated and electroactive dendritic monolayer was used for the affinity-sensing surface interacting with avidin. Electrochemical characterization of the resulting biosensor was conducted using free enzyme in electrolyte in terms of degree of surface coverage with avidin and subsequent surface shielding.

• Korean Journal of Community Nutrition
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• v.5 no.2
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• pp.324-332
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• 2000

The purpose of the study was to assess customer satisfaction concerning service quality characteristics of university foodservice by using a developed DINESERV model. In particular, it was intended to develop a tool to assess the difference between customer judgements on importance and customers perceptions with actual service delivery by university foodservices. Quenstionnaires were distributed to 1,000 university students. A total at 820 university students responded with a usable response rate of 77.7%. A statistical data analysis was completed using SAS programs for descriptive analysis; a t-test, chi-square test and Dunan's multiple range test. The results of the study are as follows; 1) The mean number of students visiting university foodservices per week for males was larger than that of females. The students' first choice depended on distance when they selected foodservices. They answered their preference as the first factor when they order a particular menu items in foodservices. The first complaint factor concerning university foodservices was the price of the food. 2) Customers was not satisfied with the quality of the service of university foodservices. The important mean score of the service quality was 3.63 out of 5, but the perception mean score of the service quality was 2.87. Therefore, there was a gap(0.76) between the importance score and perception score. 3) Customers' satisfaction with the service quality by dimensions wee int he follow order: assurance>reliability>responsiveness>tangibles>empathy. Customers were more satisfied with the service quality of contracted management than that of self-operated facilities.

• Korean Journal of Community Nutrition
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• v.5 no.4
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• pp.578-585
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• 2000

This study was aimed at examine eating behavior and food preferences of children in preschool nursery facilities. A survey was conducted on parents using questionnaires including general characteristics, eating behavior, and food habits at home and food preferences of children in 6 nursery facilities. The children involved in this study were 150 boys and 154 girls, aged 1 to 7 years old. Sixty three percent(187 children) of the children were on 'regular' meal times, and 37.0%(110 children) were on 'irregular' meal times. The major reason for their irregular meal times were 'their' concentration on other tasks'(26.6%) and 'no appetite'(25.5%). The meal eaten best by children was 'dinner' while that eaten worst was 'breakfast'. The major type of their eating habit problem was 'unbalanced diet'(62.1%), and their mothers' response to the unbalanced diet was 'trying to persuade the child'(71.6%). The number of snacks at home was one or twice a day(97.3%), and 'preference'(67.8%) was the main reason for selecting particular snacks. Their preferred staple foods were 'cooked rice with meat & vegetables and Chinese noodles', and 'noodles with bean sauce', and their preferred soup was 'seaweed soup' Also, their most preferred meat dishes were 'fried chicken' and 'thin sliced barbecued beef. Children preferred side dishes with animal foods to those with vegetable foods. Since children liked mixed dishes, it seems desirable to introduce foods which children dislike as ingredients in mixed dishes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.5
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• pp.316-321
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• 2000

Blast severity data of 39 rice varieties at 11 sites in Korea from 1997 to 1999 were analyzed using AMMI model and pattern analysis. Genotype x Environment (G$\times$E) interaction sum of squares (SS) accounted for 12 % of the total SS. Eight genotype groups and seven location groups were identified based on blast reaction pattern. The data obtained from over 21 sites with 44 test varieties from 1981 to 1996 were also considered. These were compared with the 1997-1999 data using the G$\times$E analysis results. Majority of the variability in the Korean Rice Blast Nursery (KRBN) were attributable to variations due to genotypes. Variations of G$\times$E interaction were maintained though test sites were reduced from 21 to 11 sites. Broadly compatible biological discriminative varieties identified were Nagdongbyeo and Akibare while broadly incompatible biological discriminative varieties identified were Hangangchalbyeo and Seogwangbyeo. Key sites for future evaluation work could be selected from location groups. Each location group should be represented by the site with the strongest interaction pattern. Blast responses in Cheolwon, Gyehwa, Suwon, Iksan, and Icheon showed different patterns from other locations.