• Journal of Preventive Medicine and Public Health
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• 제39권4호
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• pp.309-316
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• 2006

Objectives: Korean epidemiological studies have used reduced samples according to the subject's characteristics, such as the health services provided, the historical note with asthma, and age, to examine the acute effect of air pollution on asthma using the Korean National Health Insurance records. However, there have been few studies on whether the effects shown in these reduced samples are different from those of all samples. This study compared the effects of air pollution on asthma attacks in three reduced samples with those of entire samples. Methods: The air pollution data for $PM_{10},\;CO,\;SO_2,\;NO_2,\;and\;O_3$, and weather conditions including temperature, relative humidity, and air pressure in Seoul, 2002, were obtained from outdoor monitoring stations in Seoul. The emergency hospital visits with an asthma attack in Seoul, 2002 were extracted from the Korean National Health Insurance records. From these, the reduced samples were created by health service, historical notes with asthma, and age. A case-crossover design was adopted and the acute effects of air pollution on asthma were estimated after adjusting for weather, time trend, and seasonality. The model was applied to each reduced sample and the entire sample. Results: With respect to the health service, the effects on outpatients were similar to those for the total sample but were different for inpatients. These similar effect sizes were also observed in the reduced samples according to the historical note with asthma and age. The relative risks of $PM_{10},\;CO,\;SO_2,\;NO_2,\;and\;O_3$, among the reduced and entire samples were 1.03, 1.04-1.05, 1.02-1.03, 1.04-1.06, and 1.10-1.17, respectively. Conclusions: There was no clear evidence to show a difference between the reduced samples and the entire samples.

• 한국컴퓨터정보학회논문지
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• 제8권2호
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• pp.16-23
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• 2003

XML 문서의 저장 및 관리를 위해, 기존의 관계형 DBMS를 이용해왔다. 그러나 관계형 DBMS를 이용할 경우 XML 문서 구조를 관계형 데이터베이스로 매핑할 때, 정보 손실이 발생할 수 있으며, XML의 특성을 완벽히 반영하는 새로운 저장 관리 시스템을 새로이 구현하는 것은 많은 비용이 소요된다. 본 논문에서는 이러한 문제점을 극복하고, XML문서의 구조적 특성을 충분히 반영하기 위해, 기존의 객체지향형 DBMS인 O2 DBMS를 기본 저장 구조로 이용하면서, XML문서가 가지고 시는 다양한 특징을 수용할 수 있도록 하는 XML문서 저장 관리 시스템을 설계하고 구현하였다. 구현한 XML문서 관리 시스템 기능들로서는 전자 문서에 대한 라이브러리 서비스 기능(체크인/체크아웃, 버전제어, 사용자 액세스 관리 등), 동적 색인 및 구조 정보 검색 기능. 스타일시트를 이용한 출판 기능을 하는 XML문서 저장 관리 시스템이다.

• ESCO지
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• 통권50호
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• pp.22-25
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• 2008

2007년 매출2006년 대비 2882%증가,수주액 3148% 증가라는 대기록을 남긴 곳이 있다. 바로 (주)한성종합기술단건측사사무소(대표 김황평). 한성종합기술단은 지난해 약 151억6876만원의 매출을 기록해 2006년 5억2627만원 대비 무려 2882%가 증가하는 실적을 남겼다. 주로 ESCO분야 보안등과 냉난방교체사업을 추진하던 한성종합기술단이 지난해 2월 신재생에너지사업부를신설하면서 적극적인 영업활동을 통해 이 같은 매출 신장을 이뤄낸 것. 한성종합기술단을 찾아 지난해 실적과 올해 사업계획에 대해 들어봤다.

• 전자통신동향분석
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• 제11권2호통권40호
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• pp.159-170
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• 1996

본 고에서는 일본의 ISDN 서비스의 운영 현황에 대해 살펴보았다. 일본의 경우 '84년 ISDN시험망의 구축 및 '88년 INS-Net 64 상용 서비스를 개시한 후 현재까지 가입자가 계속 증가하는 추세로, 서비스의 종류가 상당히 다양하며 다른 망(전화망, 패킷망)과의 접속도 이루어져 있다. 국내의 경우 '90년 시험망이 구축되고 '93년 하반기부터 ISDN 상용서비스를 개시하여, 가입자의 요구를 만족시키고 타통신망과의 통합을 추진하는 과정에 있는 바, 본 고에서 분석한 일본의 현황 분석 결과는 이러한 국내 ISDN 서비스의 조기 구축에 참고모델로서 도움이 될 것이다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.109-112
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• 2001

Recently, as demands for super-high speed broad band wireless multimedia service increase, variable researches to develop wireless LAN have been carried out. In this paper, we propose and analyze LS(Least Squares)-PSA(Pilot Symbol Assisted) equalizer which compensates for each subcarrier of different attenuations and phase response for OFDM(Orthogonal Frequency Division Multiplexing)-based indoor wireless LAN systems. The proposed equalizer enhances the $E_{b}$ $N_{o}$ performance of 3dB and 4dB at BER=10$^{-2}$ as compared with LS equalizer in AWGN channel and indoor wireless channel respectively..

• Journal of applied mathematics & informatics
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• 제12권1_2호
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• pp.291-297
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• 2003

This paper considers discrete-time two-class Ge $o^{X/}$G/1 queues with preemptive repeat priority. Service times of messages of each priority class are i.i.d. according to a general discrete distribution function that may differ between two classes. Completion times are derived for the preemptive repeat identical and different priority disciplines. By using the completion time, the stability condition for our system is investigated.d.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.45-48
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• 2002

This paper presents a QoS-guaranteed traffic control system which supports QoS of realtime packet transmission for the multimedia communication. The traffic control system presented in this paper applies the integrated service model and provides QoS o(packet transmission by means of determining the packet transmission rate with the policy of network manager and the optimal resource allocation according to the end-to-end traffic load. It also provides QoS for the realtime packet transmission through the AWF2Q+ Scheduling algorithm and per-class queuing method.

• 한국정보시스템학회지:정보시스템연구
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• 제29권3호
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• pp.215-236
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• 2020

Purpose/Design The purpose of this study is summarized as follows. First, we want to derive the quality dimension of the delivery app services based on the experience of the users of the delivery app. Second, we would like to identify the continuous intention to use, taking into account the integrated nature of online and offline quality. Third, the online and offline quality factors of the delivery app services shall be checked in an exploratory manner to see how they affect perceived value, satisfaction, and continuous intention to use. In order to demonstrate the purpose of this study, a self-report survey was conducted in which respondents directly responded. A questionnaire of 295 people was identified as a valid sample and used for the final analysis. Findings The summary of the hypothesis test results is as follows. First, the system quality among the online characteristics does not have a significant impact on both perceived values and user satisfaction. Second, the hypothesis that information quality affects satisfaction and perceived value was adopted. Third, the service quality was shown to be a significant factor affecting perceived value and satisfaction. Fourth, the delivery quality among offline characteristics was found to have no significant effect on perceived value and satisfaction. Fifth, the hypothesis test of commodity quality showed that both perceived value and satisfaction had a significant impact. Sixth, satisfaction in the delivery app service showed a positive effect on the continuous intention to use.

• 한국식품위생안전성학회지
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• 제22권2호
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• pp.77-81
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• 2007

매실 리큐르 제조 부산물인 매실(매실박)에도 항균활성이 잔존하는지 알아보기 위해 생매실과 매실박을 동결 건조한 분말기 에탄을 추출물이 병원성 미생물에 대한 항균활성을 측정한 결과, 매실박의 항균활성이 생매실에 비해 감소하였으나 높은 항균활성을 유지하였다. 공시 병원성 미생물은 배양 12시간째까지 급격하게 증가하였으며 배양 24시간째 $10^7CFU/mL{\sim}10^9CFU/mL$을 나타내어 비교적 양호한 성장을 나타내었다. L. monocytogenes ATCC 19115, B. cereus KCCM 11341은 생매실과 매실박 추출물 1% 첨가시 배양 12시간째부터 성장이 관찰되지 않았으며, S. sonnei SG 48, E. coli O157:H7은 배양 24시간째에 검출되지 않았다. Sal. Typhimurium ATCC 14028의 경우, 매실박 추출물 1% 첨가구는 24시간째 $10^2CFU/mL$을 나타내어 배양 시간이 증가할수록 균수가 감소하였으나, 생매실 추출물의 경우 배양 12시간째부터 균이 검출되지 않았다. 매실 및 매실박 추출물은 L. monocytogenes Scott A의 성장을 뚜렷하게 억제하였으며, 매실박과 생매실 간의 항균활성의 차이는 뚜렷하게 나타나지 않았다. Staph. aureus KCCM 12255와 P. fluorescens ATCC 21541은 배양기간 동안 생매실 또는 매실박 첨가구가 대조구에 비해 성장이 뚜렷이 억제되었다. 공시 병원미생물에 대해 생매실 추출물은 매실박 추출물에 비해 높은 항균활성을 나타내었으며, 매실 리큐르 제조 후 부산물로 나오는 매실박 추출물도 병원성미생물에 대한 항균효과는 뚜렷하였다.

• 농업과학연구
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• 제49권3호
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• pp.619-627
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• 2022

In Korea, apples and pears are among the most important agricultural products to farmers who seek to earn money as income. Generally, farmers make decisions at various stages to maximize their income but they do not always know exactly which option will be the best one. Many previous studies were conducted to solve this problem by predicting farmers' income structure, but researchers are still exploring better approaches. Currently, machine learning technology is gaining attention as one of the new approaches for farmers' income prediction. The machine learning technique is a methodology using an algorithm that can learn independently through data. As the level of computer science develops, the performance of machine learning techniques is also improving. The purpose of this study is to predict the income structure of apples and pears using the automatic machine learning solution H2O.AI and to present some implications for apple and pear farmers. The automatic machine learning solution H2O.AI can save time and effort compared to the conventional machine learning techniques such as scikit-learn, because it works automatically to find the best solution. As a result of this research, the following findings are obtained. First, apple farmers should increase their gross income to maximize their income, instead of reducing the cost of growing apples. In particular, apple farmers mainly have to increase production in order to obtain more gross income. As a second-best option, apple farmers should decrease labor and other costs. Second, pear farmers also should increase their gross income to maximize their income but they have to increase the price of pears rather than increasing the production of pears. As a second-best option, pear farmers can decrease labor and other costs.