• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 추계학술대회 논문집
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• pp.106-111
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• 2003

This study made an experiment On fatigue crack propagation da/dn, stress intensity factor range ${\Delta}K$ respectively in room temperature and in low temperature. And we got the following characteristics from fatigue crack growth test carried Out in the environment of room temperature and law temperature at $25^{\circ}C$, $-60^{\circ}C$, $-80^{\circ}C$, and $-100^{\circ}C$ in the range of stress ratio of 0.3 by means of opening made displacement. The threshold stress intensity factor range ${\Delta}Kth$ in the early stage of fatigue crack growth (Mode I) and stress intensity factor range ${\Delta}K$ in the stable of fatigue crack growth (Made II) was decreased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at law temperature and high temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 춘계학술대회 논문집
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• pp.167-172
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• 2002

In this study, CT specimens were prepared from spring steel(SUP9) processed shot peening which was room temperature, high temperature experiment. And ire got the following characteristics from fatigue crack growth test carried out in the environment of room, and high temperature at $25^{\circ}C,\;100^{\circ}C,\;150^{\circ}C$ and $180^{\circ}C$ in the range of stress ratio of 0.3 by means of opening mode displacement. The threshold stress intensity factor range ${\Delta}Kth$ in the early stage of fatigue crack growth (Region I) and stress intensity (actor range ${\Delta}K$ in the stable of fatigue crack growth (Region II) was decreased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at high temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region.

• 한국정보통신학회논문지
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• 제17권6호
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• pp.1336-1341
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• 2013

본 연구는 역대 CES에 출품된 디지털 TV의 특성을 기술의 수요곡선과 대체곡선의 관점에서 분류하여 살펴봄으로써 스마트 환경으로 진화하는 차세대 멀티미디어에 대한 예측을 제공하고자 하였다. 분석결과 초기 디지털 TV의 형태에서 기기 간 연결성(connected)을 키워드로 하는 2013년 등장한 스마트형 디지털 TV에 이르기까지 디지털 TV는 기술 수요 곡선을 따라 진화를 거듭해왔으며, 현재 상품으로서의 수명주기의 성숙기에 이르는 것으로 나타났다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 추계학술대회 논문집(Proceeding of the KOSME 2001 Autumn Annual Meeting)
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• pp.65-70
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• 2001

In this study, CT specimens were prepared from spring steel(SUP9) processed shot peening which was room temperature, low temperature and high temperature experiment. And we got the following characteristics from fatigue crack growth test carried out in the environment of room, low temperature and high temperature at $25^{\circ}C$, -3$0^{\circ}C$, -5$0^{\circ}C$, -7$0^{\circ}C$, -10$0^{\circ}C$ and 5$0^{\circ}C$, 10$0^{\circ}C$ , 15$0^{\circ}C$, 18$0^{\circ}C$ and in the range of stress ratio of 0.05 by means of opening mode displacement. The threshold stress intensity factor range $\DeltaK_{th}$ in the early stage of fatigue crack growth (Region I ) and stress intensity factor range ΔK in the stable of fatigue crack growth (Region II) was decreased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature and high temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권8호
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• pp.2259-2277
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• 2023

We propose a probabilistic fish growth model for smart aquaculture systems equipped with IoT sensors that monitor the ecological environment. As IoT sensors permeate into smart aquaculture systems, environmental data such as oxygen level and temperature are collected frequently and automatically. However, there still exists data on fish weight, tank allocation, and other factors that are collected less frequently and manually by human workers due to technological limitations. Unlike sensor data, human-collected data are hard to obtain and are prone to poor quality due to missing data and reading errors. In a situation where different types of data are mixed, it becomes challenging to develop an effective fish growth model. This study explores the unique characteristics of such a combined environmental and weight dataset. To address these characteristics, we develop a preprocessing method and a probabilistic fish growth model using mixed data sampling (MIDAS) and overlapping mixtures of Gaussian processes (OMGP). We modify the OMGP to be applicable to prediction by setting a proper prior distribution that utilizes the characteristic that the ratio of fish groups does not significantly change as they grow. We conduct a numerical study using the eel dataset collected from a real smart aquaculture system, which reveals the promising performance of our model.

• 한국유기농업학회지
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• 제22권2호
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• pp.335-345
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• 2014

The productivity decrease in environment-friendly farming is the biggest obstacle for the development of environment-friendly food market. This paper aimed to analyze the productivity change in environment-friendly farming of fruit vegetables (oriental melon, watermelon, and strawberry). Box-Cox transformation model was used to infer the functional form of productivity change. The results showed that the periods of productivity restoration to 90% level in oriental melon, strawberry, and watermelon were 14.1 years, 11.4 years, and 6.0 years, respectively. The forms of productivity restoration of fruit vegetables showed differences due to their growth characteristics, incidences of crop pests, preference for the environment- friendly agricultural products, cultivation period and so on. Because the form and period of productivity restoration were different depending on kinds of fruit vegetable, the government policy should be established considering this point of view.

• 한국정보처리학회논문지
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• 제7권4호
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• pp.1103-1111
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• 2000

The hyper-geometric distribution software reliability growth model (HGDM) usually assumes that all the software faults detected are perfectly removed without introducing new faults. However, since new faults can be introduced during the test-and-debug phase, the perfect debugging assumption should be relaxed. In this context, Hou, Kuo and Chang [7] developed a modified HGDM for imperfect debugging environment, assuming tat the learning factor is constant. In this paper we extend the existing imperfect debugging HGDM for tow respects: introduction of random sensitivity factor and allowance of variable learning factor. Then the statistical characteristics of he suggested model are studied and its applications to two real data sets are demonstrated.

• 한국발생생물학회지:발생과생식
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• 제17권3호
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• pp.257-268
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• 2013

Morphometric changes in the Ussurian bullhead, Leiocassis ussuriensis, and the Korean bullhead, Pseudobagrus fulvidraco, were observed during the early period of growth. Yolk length, yolk height, and yolk volume in the two species decreased within 9 days post-hatching (DPH) (p<0.05). The body lengths and body heights of both species increased gradually to 150 and 130 DPH, respectively (p<0.05). The horizontal distance between the anteriormost extension of the head and the anterior insertion of the pectoral fin, the anteriormost extension of the head ${\times}$ the verticality position of the anterior insertion of the primary dorsal fin rays, and the anterior insertion of the primary dorsal fin ${\times}$ the anterior insertion of the pectoral fin were greater in the Korean bullhead than in the Ussurian bullhead (p<0.05). However, the relative sizes of the head region, pectoral fin, ventral fin, and anal fin were greater in the Ussurian bullhead than in the Korean bullhead (p<0.05), and relative body depth and the size of the outer-mandible barbel were greater in the Korean bullhead than in the Ussurian bullhead (p<0.05). The growth curves of the morphometric characteristics of both species were divided into three types.

• 한국균학회지
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• 제28권1호
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• pp.11-15
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• 2000

Phellinus pini는 진흙버섯속(Phellinus)에 속하는 버섯으로 진흙버섯속 버섯 중에서 항암저지율이 가장 높다고 알려져 있다(중국본초도감). 온도별 배양결과 $25^{\circ}C$에서 34 mm/14일(PDA배지)로 생육이 가장 좋았고 배지별 시험에서는 PDA 배지에서 30mm/10일, MCM 배지에서 28mm/10일로 나타났으며 pH $5{\sim}6$에서 균사생장이 양호하였다. 시험관을 이용한 톱밥배지 배양에서는 참나무톱밥+버드나무톱밥 +미강(4.5:4.5:1)과 참나무톱밥+소나무톱밥+미강(4.5:4.5:1)에서 균사생장이 가장 빨랐고 균사밀도는 참나무톱밥+미강(9:1)과 소나무톱밥+미강(9:1) 배지가 가장 높았다. 참나무원목에 접종한 결과 접종 60일 경과시 원목내 균사생장은 40 mm로 나타났으며 균사활착율은 26%정도였고 최초 발이 소요기간은 접종 후 110일 정도로 나타났다.

• 생물환경조절학회지
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• 제31권4호
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• pp.279-285
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• 2022

딸기 수경재배 시 일사비례제어를 이용하여 생육단계별 적정 누적일사량 기준을 설정하고자 수행하였다. 급액 방법은 외부 일사량을 기준으로 일정 누적 일사량에 도달하면 급액하였고 누적 일사량 기준은 150, 200J·cm^-2과 생육단계에 따라 200J·cm^-2에서 150J·cm^-2로 변경하는 처리를 두었다. 타이머 제어는 대조구로 설정하였다. 월별 평균 급액 횟수는 누적 일사량이 많은 3월에 150 J·cm^-2과 생육단계별(150J·cm^-2) 처리구가 5.6회, 누적일사량이 적은 12월에 200J·cm^-2과 생육단계별(200J·cm^-2) 처리구가 2.7회, 타이머는 3.6-3.8회였다. 수분이용효율은 주당 총 급액량이 적었던 타이머 처리구가 19.8g·L^-1로 일사제어 처리구에 비해 낮았다. 일사제어에 따른 생육 및 과실 특성은 차이가 없었다. 생육단계별 처리구가 총 상품과 수량은 주당 328g, 상품과율 85.3%로 가장 높았다. 딸기 수경재배 시 일사비례 급액제어 방식은 재배기간 동안 동일한 누적일사량 기준보다 생육단계별로 누적일사량을 조절하는 것이 과실의 수량 향상에 도움이 되었다.