• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.4
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• pp.25-35
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• 2002

This work describes an 8b 200MHz time-interleaved subranging analog-to-digital converter (ADC) based on a single-poly digital CMOS process. Two fine ADCs for lower digital bits of the proposed ADC employ a time-sharing double-channel architecture to increase system speed and a new reference voltage switching scheme to reduce settling time of the reference voltages and chip area. The proposed intermeshed resistor string, which generates reference voltages for fine ADCs, improves linearity and settling time of the reference voltages simultaneously. The proposed sample- and-hold amplifier(SHA) is based on a highly linear common-drain amplifier and passive differential circuits to minimize power consumption and chip area with 8b accuracy and employs input dynamic common mode feedback circuits for high dynamic performance at a 200MHz sampling rate. A new encoding circuit in a coarse ADC simplifies the signal processing between the coarse ADC and two successive fine ADCs.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.413-414
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• 2011

최근 전기 자동차 배터리의 전하 균일 장치의 관심이 증가됨에 따라 제어가 간단하며 비교적 적은 소자를 통한 개별 전하 균일 장치 개발의 필요성이 대두되고 있다. 이 논문에서는 직렬 연결된 리튬 이온 배터리를 위한 개별 셀 전하 균일 장치를 제안한다. 이 장치는 하나의 공통된 인버터 동작을 공유하면서 개별로 나눠진 트렌스포머를 간단한 제어 동작을 통해 선택적으로 동작 시키는 방식을 사용한다. 이 구조를 통해 제안하는 전하 균일 장치는 전하 균일 전류를 제어함에 있어 간단한 구조와 제어 방법을 얻을 수 있다. 또한 대용량 배터리를 위한 큰 전하 균일 전류를 얻음에 있어 제안 회로는 신뢰성 있는 적은 수의 회로 소자 수를 가진다. 이 논문에서는 제안하는 장치의 회로와 동작 방법을 설명하면서, 8 개 리튬 이온 배터리를 위한 전하 균일 실험을 통해 제안 장치의 전하 균일 성능을 증명한다.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.363-370
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• 2002

A substrate network model characterizing substrate effect of submicron MOS transistors for RF operation and its parameter extraction with physically meaningful values are presented. The proposed substrate network model includes a single resistance and inductance originated from ring-type substrate contacts around active devices. Model parameters are extracted from S-parameter data measured from common-bulk configured MOS transistors with floating gate and use where needed with out any optimization. The proposed modeling technique has been applied to various-sized MOS transistors. Excellent agreement the measurement data and the simulation results using extracted substrate network model up to 30GHz.

• TTA Journal
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• s.43
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• pp.129-149
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• 1996

본 고에서는 Global Information Infrastructure (GII) 구축을 위하여 국제 표준화기구인 ITU, ISO, IEC 간에 최근 활동현황에 대하여 소개한다. 이를 위해 지난 1996년 1월 17-19일간에 열린 Global Information Infrastructure (GII)를 위하여 ITU-T 내에 Joint Rapporteur Group(JRG)회의 결과와 1월 24-26일간에 열린 ISO/IEC/ITU International GII 세미나에서 논의된 주요 결과를 정리한다. 먼저 ITU-T JRG 회의는 차기 연구회기(1997년-2000년)동안에 GII 표준화 절차와 기술적인 이슈를 ITU-T SG13을 중심으로 모든 ITU-T 스터디 그룹이 나누어서 진행해야될 업무를 정리하는 것이며 이는 1996년 10월에 개최될 WTSC에 제출할 예정이다. 다음으로 ISO/IEC/ITU International GII 세미나는 GII와 관련된 ITU, ISO, IEC 소속의 약 100여개의 표준화 그룹이 모여서 국제적으로 효과적인 작업을 하기 위한 방안을 모색하기 위하여 개최된 세미나이다. 여기는 통신망 관련하여 ITU, 상위 데이터 서비스와 관련된 ISO, 그리고 가전기기 및 단말장치와 관련된 IEC가 공통의 정보 하부구조의 건설을 위하여 더 이상 각기 표준화를 진행해서는 안 된다는 인식을 바탕으로 한 것이다.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.2
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• pp.95-102
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• 2004

In this paper, Experience Sensitive Cumulative Neural Network (ESCNN) is introduced, which can cumulate the same or similar experiences. As the same or similar training patterns are cumulated in the network, the system recognizes more important information in the training patterns. The functions of forgetting less important information and attending more important information resided in the training patterns are surveyed and implemented by simulations. The system behaves well under the noisy circumstances due to its forgetting and/or attending properties, even in 50 percents noisy environments. This paper also describes the creation of the generalized patterns for the input training patterns.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.243-248
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• 2014

The demand for messenger service goes on growing rapidly with widespread use of smartphones. Generally, the smartphone messenger provides group communication functions in which users can make the group and communicate with each other. In the mobile meeting, the attendees can participate in the meeting with use of smartphone messengers wherever they are. To make the mobile meeting put to practical use, the mobility and privacy should be ensured to attendees. To satisfy the mobility requirement, the user which is not belong to the group members should not be able to participate in the meeting. To ensure the privacy requirement, the attendees should have not to repudiate the meeting results. In this study, the mobile meeting authentication scheme is proposed which provides mobility and privacy. The proposed scheme consists of meeting group creation, group key generation, group signature and verification protocols. All attendees should have to participate in the signature verification because it is based on the challenge-response type protocol. Thus, it's not possible to collude with malicious attendees to change the meeting results.

• Journal of KIISE:Databases
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• v.33 no.7
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• pp.754-765
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• 2006

In XML keyword search, a search result is defined as a set of the smallest elements (i.e., least common ancestors) containing all query keywords and a granularity of indexing is an XML element instead of a document. Under the conventional index structure, all least common ancestors produced by the combination of the elements, each of which contains a query keyword, are considered as a search result. In this paper, to avoid unnecessary operations of producing the least common ancestors and reduce query process time, we describe a way to construct a partitioned index composed of several partitions and produce a search result by merging those partitions if necessary. When a search result is restricted to be composed of the least common ancestors whose depths are higher than a given minimum depth, under the proposed partitioned index structure, search systems can reduce the query process time by considering only combinations of the elements belonging to the same partition. Even though the minimum depth is not given or unknown, search systems can obtain a search result with the partitioned index, which requires the same query process time to obtain the search result with non-partitioned index. Our experiment was conducted with the XML documents provided by the DBLP site and INEX2003, and the partitioned index could reduce a substantial amount of query processing time when the minimum depth is given.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.815-833
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• 2016

This study investigated children's (grade 3 to 9) responses to assessment items on energy as a cross-cutting concept in order to get basic information for a learning progression. The assessment consisted of 8 ordered multiple-choice items at the contexts of electric circuit, mechanical energy of falling objects, phase change of matter, dissolution, biological phenomena of a lizard, food chain, radiative equilibrium between Sun and Earth, and the system of water cycling. Children's responses to each item were analyzed with using cross-tabulations in terms of grades and item option levels and Wright map and Differential item functioning based on Rasch modeled item response analysis. The results offered empirical evidence of children's development of understanding energy from relation between energy and its phenomena, types of energy, transfer and conversion of energy, towards conservation and equilibrium of energy for all of eight contexts. Children of each grade did not fully understand energy conservation. As grade goes up, their understandings of energy transfer and conversion were differentiated across the contexts and topics of energy. According to Rasch analysis, children had easier understanding of energy on dissolution and poorer understanding of energy on water cycling than that on other contexts. It was discussed and suggested that the results of this study help us organize science topics with regard to energy when developing new national science curriculum.

• Journal of The Korean Association For Science Education
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• v.20 no.2
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• pp.274-287
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• 2000

This study was performed the analysis of four kinds of common science textbooks based on the 6th curriculum. Particularly, inquiry activity part was analyzed by the three dimension framework which consists of inquiry content dimension, inquiry process dimension and inquiry context dimension. In the analysis of the inquiry content dimension of inquiry activities, the contents revised by 6th curriculum of common science textbook was accomplished through various inquiry activities. The number of inquiry activity in four textbooks was similar as about 16. The For the analysis of inquiry process dimension, 'interpreting data and formulating generalizations' category (39.1%) was most emphasized and the categories of 'observation and measuring'(30.8%), and 'building, testing and revising the theoretical model' (16.5 %), 'seeing a problem and seeking ways to solve it' (13.5%) follow in order. As for the analysis of the inquiry context dimension, the proportion of STS related contents in inquiry activities was only 18%. So, we propose that STS related contents would increase the proportion for the following textbook.

• Parasites, Hosts and Diseases
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• v.27 no.1
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• pp.1-8
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• 1989

Serodiagnosis of parasitic infections is widely used, since parasites or their eggs are not always detected by ordinary methods. The sensitive tests such as ELISA are highly dependent on the purity of antigens used. To solve this problem. many workers have tried to find species-specific components of antigens, The present study was performed to determine the antigenic profile of crude saline extracts of 3, 5, 8 and 12-week old p. westermani worms, which were collected from experimentally infected cats, based on SDS-PAGE and immunoblot technique. The results were as follows: 1. The SDS-PAGE showed at least 30 Protein bands ranging from 229 kDa to 10 kDa molecular weight. The protein components of p. wsstermani changed chronologically during its developmental period. The 229 kDa band was recognized only in 12-week old worms ($$SEP_{l2}$). 2. Analysis by ELISA showed a significant increase in antibody levels at 3 weeks in infected cats using crude saline extract antigens ($SEP_3,{\;}SEP_5,{\;}SEP_8,{\;}SEP_{l2}$). 3. By EITB using $SEP_3$ and $SEP_5$ infected cats recognisea major protein bands with molecular weight of 60, 35, 28, 25 or 21 kDa at 3~12 weeks of infection, and 3 additional antigens, 19, 13 and 10 kDa, were detected at 8~12 weeks of infections. 4. Using $SEP_8$ 5 antigens, 91, 85, 31, 25 and 21 kDa, were consistently detected by all infected sera tested. In addition, 3 antigens of lg. 13 and 10 kDa were detected at 8~12 weeks of infection. Using $SEP_12$, similar results were obtained with that by using $SEP_8$ and 1 additional antigen of 229 kDa, specifically reacting with the sera from 12 weeks of in(traction, was recognized.