• 한국전자통신학회논문지
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• 제15권1호
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• pp.161-166
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• 2020

본 논문은 통합 베이즈 티코노프 정규화 방법을 확장하는 것을 제시한다. 통합된 방법은 티코노프 정규화 모수와 베이즈 하이퍼 모수들의 관계를 정립하고 최대 사후 확률과 근거 프레임워크를 사용한 정규화 모수를 구하는 공식을 제시한다. 데이터 행렬의 차원이 m by n (m >= n)일 때, total misfit는 기존의 m에서 m ± n로 확장된다. 따라서 탐색 범위도 1에서 2n+1개의 정수로 확장된다. 선형 탐색보다는 황금분할 탐색으로 시간을 줄인다. 상대오차를 최적화하는 새로운 벤치마크를 제안하고 이를 목표로 하는 새 모델 선택 판정기준을 소개한다. 실험결과는 영상 복원 문제에 대하여 제안하는 방법의 효능을 보여준다.

• 대한전자공학회논문지TC
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• 제43권11호
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• pp.216-220
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• 2006

모노폴 안테나의 크기를 줄이기 위한 방법으로 헬릭스 형태로 변형하는 것과 적층형 구조를 사용하는 방법이 있다. 본 논문에서는 제안한 적층형 헬릭스 안테나의 구조 변수에 따른 동작 주파수의 관계식을 제안하였다. 그리고 구조 변수에 따른 동작 주파수의 변화 양상을 이용하여 PCS 와 IMT-2000 대역에서 동작하는 이중대역 적층형 헬릭스 칩 안테나를 제작하였다. 제작된 안테나는 유전율 4.2 를 갖는 FR-4 유전체를 사용하였고 면적은 $15{\times}7.5{\times}0.4mm^3$ 이다. 안테나의 적층을 위해 직경이 0.35mm 이고 높이가 0.4mm 인 비아 홀을 사용하였다. 측정한 대역폭(VSWR<2)은 약 400MHz이다.

• 산업기술연구
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• 제21권B호
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• pp.233-240
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• 2001

This research was conducted with the aim of efficiently managing large scale of rivers such like Songyang-river through predicting water quality change with analyzing the characteristics of the flowing in nutrients and pollutants. The main result will be used as basic data for effectively operating reservoirs through controling water quality and quantity. The relationship between quantity of flow and water quality was analyzed and pollution loading into the basin was estimated. Three areas of Soyang-river upstream and one area of Suip-cheon in Yanggu-gun were selected as research sites. Flow and water quality were measured simultaneously. The relation between quantity of discharge and pollution concentration and between quantity of discharge and pollution loading were analyzed by statistical method, respectively. We provided a rating curve through measuring quantity of discharge(collecting quantity of discharge) and pollutograph and pollution loading curve through water quality data. Also, we analyzed the correlation between quantity of discharge per unit area and pollution loading per unit area in each basin. As resurt of this research, Buk-cheon spot revealed an excellent first grade water quality for the items including $BOD_5$, DO, and SS. The correlation coefficient between Buk-cheon spot's quantity of discharge and pollution loading was 0.896~0.996, showing the validity of analysis applying correlation curve formula of quantity of discharge and pollution loading in the same spot. Also, pollution loading per unit area of the items including $BOD_5$, COD, DO, SS, T-N, T-P increased as the area of basins get increased following the sequence of Buk-cheon, Suip-cheon, Naelin-cheon spots.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권10호
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• pp.5149-5167
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• 2017

Reducing energy consumption in a wireless video sensor network (WVSN) is a crucial problem because of the high video data volume and severe energy constraints of battery-powered WVSN nodes. In this paper, we present an adaptive dynamic resizing approach for a SRAM communication buffer in a WVSN node in order to reduce the energy consumption and thereby, to maximize the lifetime of the WVSN nodes. To reduce the power consumption of the communication part, which is typically the most energy-consuming component in the WVSN nodes, the radio needs to remain turned off during the data buffer-filling period as well as idle period. As the radio ON/OFF transition incurs extra energy consumption, we need to reduce the ON/OFF transition frequency, which requires a large-sized buffer. However, a large-sized SRAM buffer results in more energy consumption because SRAM power consumption is proportional to the memory size. We can dynamically adjust any active buffer memory size by utilizing a power-gating technique to reflect the optimal control on the buffer size. This paper aims at finding the optimal buffer size, based on the trade-off between the respective energy consumption ratios of the communication buffer and the radio part, respectively. We derive a formula showing the relationship between control variables, including active buffer size and total energy consumption, to mathematically determine the optimal buffer size for any given conditions to minimize total energy consumption. Simulation results show that the overall energy reduction, using our approach, is up to 40.48% (26.96% on average) compared to the conventional wireless communication scheme. In addition, the lifetime of the WVSN node has been extended by 22.17% on average, compared to the existing approaches.

• 수산해양기술연구
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• 제23권2호
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• pp.72-79
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• 1987

국산 소형어선용 예연소실식 디이젤기관에 혼합연료유(정유+중유)를 사용할 경우 혼합연료유의 성질, 연소특성 및 기관성능에 관하여 실험한 결과를 요약하면 다음과 같다. 1) 혼합연료유의 혼합비율(중량비율)이 증가함에 따라 비중은 선형적으로 증가하였고, 점도-온도 곡선은 Walther-ASTM 식과 일치하였으며, 착화성지수인 CCAI의 값은 기울기 1.0에 가까운 직선으로 증가하였다. 2) 동일운전조건에서 착화지연은 CCAI의 값이 810(혼합비율 60%)까지는 미소하게 증가하였으나, 그 이상의 값에서는 현저하게 증가하였다. 따라서, 혼합연료유의 착화성을 나타내는 CCAI의 값은 810 이상에서 적용하는 것이 타당하다. 3) 연소최고압력은 혼합비율 40%까지 증가하다가 감소하였으며, 그을음농도는 60%부터 현저하게 증가하였으므로, 본 실험에서 무그을음 연료비절감의 안전운전 혼합비율은 50%가 적당하다

• 수산해양기술연구
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• 제23권2호
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• pp.26-26
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• 1987

국산 소형어선용 예연소실식 디이젤기관에 혼합연료유(정유+중유)를 사용할 경우 혼합연료유의 성질, 연소특성 및 기관성능에 관하여 실험한 결과를 요약하면 다음과 같다. 1) 혼합연료유의 혼합비율(중량비율)이 증가함에 따라 비중은 선형적으로 증가하였고, 점도-온도 곡선은 Walther-ASTM 식과 일치하였으며, 착화성지수인 CCAI의 값은 기울기 1.0에 가까운 직선으로 증가하였다. 2) 동일운전조건에서 착화지연은 CCAI의 값이 810(혼합비율 60%)까지는 미소하게 증가하였으나, 그 이상의 값에서는 현저하게 증가하였다. 따라서, 혼합연료유의 착화성을 나타내는 CCAI의 값은 810 이상에서 적용하는 것이 타당하다. 3) 연소최고압력은 혼합비율 40%까지 증가하다가 감소하였으며, 그을음농도는 60%부터 현저하게 증가하였으므로, 본 실험에서 무그을음 연료비절감의 안전운전 혼합비율은 50%가 적당하다

• 콘크리트학회논문집
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• 제16권6호
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• pp.785-794
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• 2004

이 논문은 휨과 전단이 동시에 작용하고 있는 철근콘크리트 보에서 전단은 휨모멘트의 변화율(V=dM/dx)이라는 기본 관계식에 근거한 새로운 트러스모델링기법을 제안하는 것이다. 이 새로운 모델의 핵심은 보의 경간에서 내부 모멘트 팔길이의 변화를 고려함으로써, 보의 전단 저항 메커니즘을 아치작용과 보작용이라는 두 기본 성분의 합으로 표현할 수 있게 한 것이다. 이두 작용에 의한 전단 저항 구성비는 상호 변형 적합조건을 적용하여 계산하였는데, 이 때 수정압축장이론과 CEB/FIP MC-90의 인장강화효과 공식을 이용하였다. 이렇게 함으로써 전단과 모멘트 관계식 V=dM/dx을 수치적으로 복제할 수 있는 새로운 트러스모델을 결정하였다.

• 물과 미래
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• 제15권3호
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• pp.37-47
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• 1982

본 연구는 확정론적 모의기법 중 영국도로시험연구소에서 개발한 R.R.L법을 포장 지역이 넓은 인천에 위치한 간석동 아파트에 적용하여 그 실용성을 검토하였다. 인천지방의 전체적이고 합리적인 결과를 얻기 위하여 과거 28년간 누가우량 곡선에서 얻은 10mm 이상 되는 강우 450개를 5분 간격으로 읽어 확률빈도통계인 HUFF의 사분위법을 이용 확률빈도백분율곡선을 얻어 R.R.L법에 적용하였다. 인천지방의 확률빈도백분률 곡선은 제2 구간이 전체의 43.2%를 나타내므로 설계우량의 우량주상도는 제을구간에서 추출함이 바람직하다.

• 한국응급구조학회지
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• 제7권1호
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• pp.55-64
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• 2003

The purposes of this study which was conducted by applying three projection formulae to the data from admission quota for paramedic of the Ministry of Education & Human Resources Development the number of ambulances the number of emergency medical centers of the Ministry of Health & Welfare and rate of successful candidates of annual report of the National Health Personnel Licensing Examination Board were to find out demand and supply of paramedic from 2002 to 2045 and to expand scope of practice of paramedic in Korea. The conclusions from this study were summarized as follows; (1) The simple formulae derived from the projection formula of the Economic Planning Board were applied under the present Emergency Medical Services Act including qualifying over 3-years experienced EMT-Basic for paramedic examinee, stationing paramedic or EMT-Basic or physician or nurse per ambulance, stationing paramedic or EMT-Basic per emergency medical center and under the amended Emergency Medical Services Act including qualifying only paramedic graduate for paramedic examinee, stationing 4.5 paramedics per ambulance, stationing 10 to 2 paramedics per emergency medical center. (2) It was estimated that on the American basis of 5.6 EMTs per 10,000 in 1996, the number of paramedics under the present act will reach the basis before 2020, the number of paramedics under the amended act will reach the basis about 2040. (3) It was estimated that on the basis of 22,000 paramedics demanded from the number of ambulances, the number of emergency medical centers in 2001, the number of paramedics under the present act will reach the basis before 2015, the number of paramedics under the amended act will reach the basis about 2030. (4) There was relationship between requirements for emergency medical centers scope of practice of paramedic in the act and demand-supply of paramedic, this necessitates surveys, studies, amendment of the act, legalization for expanded scope of practice of paramedic including EMD, instructor, teacher of safety. (5) This study which includes only expanded scope of practice of paramedic and projection for paramedic in the act needs complementary studies such as decision-making process in health manpower policy and so on.

• Nutrition Research and Practice
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• 제9권1호
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• pp.57-62
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• 2015

BACKGROUND/OBJECTIVES: The prevalence of atopic dermatitis in infants is increasing worldwide. However, the nutrient intake status of infants with atopic dermatitis has not been studied properly. This study was conducted to compare the nutrient intake status of infants in the weaning period with atopic dermatitis by feeding type. MATERIALS/METHODS: Feeding types, nutrient intake status and growth status of 98 infants with atopic dermatitis from age 6 to 12 months were investigated. Feeding types were surveyed using questionnaires, and daily intakes were recorded by mothers using the 24-hour recall method. Growth and iron status were also measured. RESULTS: The result showed that breastfed infants consumed less energy and 13 nutrients compared to formula-fed or mixed-fed infants (P < 0.001). The breastfed group showed a significantly lower intake rate to the Dietary Reference Intakes for Koreans than the other two groups (P < 0.001). In addition, they consumed less than 75% of the recommended intakes in all nutrients, except for protein and vitamin A, and in particular, iron intake was very low, showing just 18.7% of the recommended intake. There was no significant difference in growth by feeding type, but breastfed infants showed a significantly higher rate of iron deficiency anemia (P < 0.001). CONCLUSIONS: Continuous management programs should be prepared for breastfed infants with atopic dermatitis, who are in a period when rapid growth takes place and proper nutrient intake is essential.