• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.314-314
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• 2022

In the production of rice flour, wet milling is a method of milling rice after soaking it in water, and it takes a lot of time and cost from milling to drying. To overcome this problem, the floury type rice was developed for dry milling and it is known to have round starch granules, low content of damaged starch after milling, and a starch structure similar to wheat. Because of its unique properties different from normal rice, it is necessary to research on processing and characteristics of floury-type rice to expand its utility in the food industry. Therefore, this study aimed to prepare the pregelatinized floury type rice (Baromi2) by autoclave and investigate their physicochemical properties. As the heat treatment time increased, the brightness decreased from 83.8 to 76.8, however, both redness and yellowness increased from 0.57 to 4.5 and from 14.58 to 21.13, respectively. Despite of same treatment time, soaking in water (10 min) before autoclaving increased the solubility and swelling power of Baromi2 over 2 times. The peak viscosity of native Baromi2 was over 2000 RVU, on the other hand, there was a significantly decrease to less than 1000 RVU of pregelatinized Baromi2. Heat treatment without immersion caused partial gelatinization of starch, resulting that some starch granules maintaining their integrity. Whereas there were no starch granules in heat treatment with soaking in water due to complete gelatinization. This study would be helpful to the suggestion of using heat-treated floury-type rice as an intermediate material in the food industry in the future.

• Steel and Composite Structures
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• 제51권2호
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• pp.185-202
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• 2024

In this research paper, and for the first time, wave propagations in sigmoidal imperfect functionally graded material plates are investigated using a simplified quasi-three-dimensionally higher shear deformation theory (Quasi-3D HSDTs). By employing an indeterminate integral for the transverse displacement in the shear components, the number of unknowns and governing equations in the current theory is reduced, thereby simplifying its application. Consequently, the present theories exhibit five fewer unknown variables compared to other Quasi-3D theories documented in the literature, eliminating the need for any correction coefficients as seen in the first shear deformation theory. The material properties of the functionally graded plates smoothly vary across the cross-section according to a sigmoid power law. The plates are considered imperfect, indicating a pore distribution throughout their thickness. The distribution of porosities is categorized into two types: even or uneven, with linear (L)-Type, exponential (E)-Type, logarithmic (Log)-Type, and Sinus (S)-Type distributions. The current quasi-3D shear deformation theories are applied to formulate governing equations for determining wave frequencies, and phase velocities are derived using Hamilton's principle. Dispersion relations are assumed as an analytical solution, and they are applied to obtain wave frequencies and phase velocities. A comprehensive parametric study is conducted to elucidate the influences of wavenumber, volume fraction, thickness ratio, and types of porosity distributions on wave propagation and phase velocities of the S-FGM plate. The findings of this investigation hold potential utility for studying and designing techniques for ultrasonic inspection and structural health monitoring.

• 문화기술의 융합
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• 제10권1호
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• pp.453-458
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• 2024

전 세계적으로 기후 위기와 에너지 비용 증가 등의 문제로 인해 에너지 절감과 관리에 대한 관심이 증대되고 있다. 대한민국의 경우 전체 에너지 사용량의 약 53.5%가 산업 단지에서 사용하여 이와 관련한 에너지 절감 포인트를 찾고자 유사한 에너지 유틸리티를 사용하는 기업 간의 "공유 네트워크 유틸리티 플랜트"를 통해 문제점을 개선하고자 하였다. 이러한 에너지 절감을 위해서 활용하는 다양한 기법들과 공장의 안정적인 운영을 위해서는 데이터의 안정적 수급이 그 무엇보다 중요하다. 그를 위해 데이터를 안정적으로 수급할 수 있는지에 대해 알아볼 수 있는 이상 데이터 감지 시스템과 알림 시스템의 대다수는 에너지 관리 시스템에 종속되어 한계가 있었고 에너지 관리 시스템의 구축은 대단위 시스템의 구축으로 공간, 에너지적 한계가 있는 소형 공장에서 구축이 어려웠다. 본 논문에서는 문제점들을 극복하고자 적은 공간과 전력을 소비하는 임베디드 디바이스에 데이터 수집 시스템과 이상 데이터 감지 알림 시스템를 구축하고, 데이터 수집을 하는 보편적인 기관에서 이상 데이터 감지 알림 시스템의 활용 가능성과 구축 과정에 대한 연구를 수행하였다.

• 유통과학연구
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• 제12권4호
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• pp.31-39
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• 2014

Purpose - This study investigates the following two issues. First, we attempt to find the important determinants of housing investment and to identify their significance rank using survey panel data. Recently, the expansion of global uncertainty in the real estate market has directly and indirectly influenced the Korean housing market; households demonstrate a sensitive reaction to changes in that market. Therefore, this study aims to draw conclusions from understanding how the impact of financial strength of the household is related to house investment. Second, we attempt to verify the effectiveness of diverse indices of financial strength such as DTI, LTV, and PIR as measures to monitor the housing market. In the continuous housing market recession after the global crisis, the government places top priority on residence stability. However, the government still imposes forceful restraints on indices of financial strength. We believe this study verifies the utility of these regulations when used in the housing market. Research design, data, and methodology - The data source for this study is the "National Survey of Tax and Benefit" from 2007 (1st) to 2011 (5th) by the Korea Institute of Public Finance. Based on this survey data, we use panel data of 3,838 households that have been surveyed continuously for 5 years. We sort the base variables according to relevance of house investment criteria using the decision tree model (DTM), which is the standard decision-making model for data-mining techniques. The DTM method is known as a powerful methodology to identify contributory variables for predictive power. In addition, we analyze how important explanatory variables and the financial strength index of households affect housing investment with the binary logistic multi-regressive model. Based on the analyses, we conclude that the financial strength index has a significant role in house investment demand. Results - The results of this research are as follows: 1) The determinants of housing investment are age, consumption expenditures, income, total assets, rent deposit, housing price, habits satisfaction, housing scale, number of household members, and debt related to housing. 2) The impact power of these determinants has changed more or less annually due to economic situations and housing market conditions. The level of consumption expenditure and income are the main determinants before 2009; however, the determinants of housing investment changed to indices of the financial strength of households, i.e., DTI, LTV, and PIR, after 2009. 3) Most of all, since 2009, housing loans has been a more important variable than the level of consumption in making housing market decisions. Conclusions - The results of this research show that sound financing of households has a stronger effect on housing investment than reduced consumption expenditures. At the same time, the key indices that must be monitored by the government under economic emergency conditions differ from those requiring monitoring under normal market conditions; therefore, political indices to encourage and promote the housing market must be divided based on market conditions.

• 한국산학기술학회논문지
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• 제19권8호
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• pp.312-321
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• 2018

한국의 수요자원(Demand Response, DR) 거래시장은 자연재해 또는 예기치 않은 발전소 사고로 인한 전력수급 위기 시 최대수요를 억제하며, 발전소 건설비용 절감 및 운영예비력 확보를 위한 목적으로 운영되고 있다. 수요자원 거래시장에 참여한 수용가는 전력거래소로부터 수요 감축 1시간 전 급전지시를 통보 받으며, 요청된 수요자원 감축을 통하여 기본급과 실적금을 정산 받는다. 본 논문에서는 냉각 시스템과 ESS을 갖춘 수용가가 계시별요금제와 수요자원 거래시장에 동시 참여 시, 최적 운영계획 수립을 위한 DR 에너지관리 알고리즘을 제안 하였다. 제안된 알고리즘은 주위온도 예측오차가 있는 전일 운영 스케줄링과 DR 운영일 리스케줄링의 두 가지 운영 스케줄링으로 구성된다. 전일 운영 스케줄링의 경우, 냉각 시스템, ESS의 운영스케줄링은 과거 주위온도 데이터를 기반으로 생성된 주위온도 시나리오와 불확실한 DR감축 시나리오에 의해 결정된다. 또한 DR 운영일에 대한 리스케줄링은 수용가의 DR 수익과 건물내부 열괘적성이 보장되며 제안된 방법은 혼합정수 선형 프로그래밍(Mixed Integer Linear Programming, MILP)에 의해 기대 에너지 비용을 최소화한다.

• 한국농공학회지
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• 제17권4호
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• pp.3897-3920
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• 1975

Since the most of Korean dairy and cattle raising farms are too small to introduce western mechanized farming, it is necessary to develope small size equipments. This study has been carried to develop a rotary mower as on attachment of 8 to 10 horse powertiller which is widely spread in rural area. It will not ony be helpfull for the farmers to harvesting hay grass but also desirable to increase the power tiller utility. The protto type rotary mower designed through the fundamental investigations, has been modified and improved through the field trials, and a series of field tests has been carried to investigate its performance and economic feasibility comparing with existing vailable harvesting equipments. The results are as follows; 1. To increase the stability, two guide wheels are attached to both side of the protto type rotary mower. 2. To prevent the clinging of tall grasses, the vertical driving shafts are covered with cylindrical protectors. 3. The cutting height is adjustable in 8 steps from 2.5 to 20 centimeters by changing the length of guide wheel legs. 4. The practical Critical cutting speed were always higher than theoretical value in both case of single cutting blade and three when the cutting depth was 25 millimeter. 5. The peripheral speed of cutting blade was varied in response to the change of engine speed, mean while the peripheral speed was adequate as it was changhed from 25 to 35 meter per second when the power tiller is operated in proper working ground speed. 6. The time requirement to harvest 10 a were 88.7, 54.6 and 41.4 minutes for the first, second and third stage of ground speed respectively, and because of the difficulty of delivery, it was observed that operating with fourth stage of ground speed was not recomanendable when the grass height is taller than 90 centimeters. 7. The performance of rotary mower were 1.1-1.7, 1.4-4.0, 3.8-11.8 and 7.4-22.0 times of reciprocating mower, portable disc type cutter, hay scythe and ordinary sickle respectively. 8. When the slope exceeds, 20 degree the downward harvesting operation was impossible because of the excessive front end weight, while less than 5 degree of land slope did not effect in field operation. 9. Increased traveling spee caused higher cutting height and slight cutting failure, but seems not to effect to the gross yield, and the efficiency of cutting width were from 83 to 94 precent. 10. Tn rank of economy were rotary mower (3,2 stage operation), reciprocating mower, hay scythe, portable disc type cutter and sickle in order when the annul operation exdeeds 100 hours. From the above results, it is convinced that the protto type rotary mower is good enough to the livestock farmers as a hay harvesting equipment because of its economy, hardiness in operating and its out standing performance and hopefully it will contribute to the extension of Korean livestock farming.

• 한국정보처리학회논문지
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• 제4권7호
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• pp.1749-1758
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• 1997

전력수요의 예측은 예측기간에 따라 중장기 전력수요 예측과 단기 부하 예측으로 구분할 수 있다. 기존의 단기 부하예측은 주로 역전파 알고리즘(back propagation algorithm)다층퍼셉트론을 이용하여 예측을 하였으나 이는 학습시간이 많이 걸릴 뿐만 아니라 학습도중에 지역최소점(local minima)에 빠져 학습이 계속되지 못한다는 문제가 있다. 본 논문은 이러한 역전파 알고리즘의 문제점을 해결할 수 있는 방법으로 Radial Basis 함수(Radial Basis Function)를 이용하여 동적 단기부하 예측 모형을 제안한다. Radial Basis 함수는 하나의 은닉층(hidden layer)을 갖고 있으며, 전방향(feed-forward)학습을 한다는 특징이 있다. 본 논문에서 제안한 단기 부하 예측모형은 학습을 하기 위하여 시간대별 부하량을 클러스터링 하고, 이 클러스터의 중심값을 Radial Basis 함수의 은닉층으로 하여 학습을 한 다음 예측하고자 하는 패턴을 한 단위로 하여 시단대별로 예측하였다. 기존의 연구에서의 클러스터링 방법으로는 통계학의 K-Means 방법이나 Kohonen의 LVQ(Learning Vector Quantization)을 주로 이용하였으나 본 논문에서는 패턴의 분류에 있어서 다른 알고리즘보다 편차가 작은 Pal, et. al.의 GLVQ(Generalized LVQ) 알고리즘을 이용하였다. 본 논문에서 이용한 데이타는 1995년 3월 1일-3일, 6월 1일-3일, 7월 1일-3일, 9월 1일-3일, 11월 1일-3일의 72시간 데이타를 입력하여 월별 4일의 24시간의 예측시간으로 예측하였다. 실험결과 월별 1일과 3일까지의 학습데이타로 1시간 후의 부하량을 24시간동안 예측한 결과 1.3795%의 평균 오차율로 예측하였다.

• 한국지능시스템학회논문지
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• 제9권4호
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• pp.420-425
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• 1999

최대수요전력 예측과 제어의 목적은 공장 또는 빌딩등의 전력수용가의 입장에서 수시로 변동하는 부하의추이를 파악 예측하여 에너지 합리화 경제성 증대 산업기기의 보호 수용가의 비용절감과 더불어 크게는 국가적인 전력시스템안정화를 가져가기 위함에 있다. 최대수요전력 예측/제어를 위한 기존의 방법들은 수용가 특성이나 계절별 요일별 차이를 고려하지 않고 고정된 알고리즘에 의해 예측값이 결정되므로 환경변화에 적극적인 대응능력이 부족한 단점이있다. 이와같은 문제점의 해결을 위해 본 논문에서는 현재 많은 연구가 되고 있는 SOFM 신경망을 이용한 예측 방법과 예측치의 보정방법으로 퍼지제어길르 추가한 형태의 최대수요전력예측 제어기를 제안한다, 예측방법의 경우 유동적이며 적은 구간을 통하여 순시부하처럼 변동이 많은 데이터에 대하여 예측시간을 단축함과 동시에 오차를 줄여나갈수 있다. 또한 2단계의 학습을 통하여 SOFMd의 출력값이 패턴이 아닌 예측치가 될 수 있도록 변형하였으며 패턴자체의 변화에 대응하여 패턴오차를 이용하여재학습을 하도록 하여 불안정한 전력에 대하여 보완한다. 그리고 예측후반부에 퍼지제어기를 연결하여 예측의 신뢰성을 높이는 안정된 예측구조를 가지고 있다. 실험결과 시계열 예측방법인 지수평활법보다 제안된 예측/제어 방법이 우수함을 확인하였다.

• 에너지공학
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• 제25권4호
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• pp.93-102
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• 2016

V2G (Vehicle-to-Grid)는 전기자동차 배터리에 저장된 전기를 전력판매사의 전력망을 통해 되파는 양방향 전력 전송 기술이다. V2G 시스템을 활용하는 전기자동차 운전자는 전기요금이 저렴한 심야에 충전한 뒤 출퇴근시 사용하고 남은 전력을 전력사용량이 많고 전기요금이 높은 주간에 판매하므로, 피크시 전력수급의 안정성이 향상된다. 이에 정부는 V2G 인프라 구축 및 지원 대책을 마련하면서 V2G 시스템에 대한 잠재적 소비자의 선호 정보를 요구하고 있다. 본 논문에서는 잠재적 소비자인 일반 국민 1,000명을 대상으로 한 일대일 개별면접 설문조사를 통해 수집된 자료를 수집하였다. 소비자의 선호를 분석하기 위해 경제학적 기법인 선택실험법을 적용한다. V2G 시스템의 속성으로 잔존 전력량, 전력 판매시간, 의무접속시간, 현행 차량가액에 추가하는 가격으로 평가된 지불의 사액이라는 4개를 고려하였다. 분석모형으로는 우선 다항로짓모형을 적용하였는데 '비관련 대안의 독립성' 가정이 위배되어, 이 가정을 요구하지 않는 중첩로짓모형을 최종적으로 적용하였다. 효용함수의 모든 추정계수는 유의수준 10%에서 통계적으로 유의하였다. 속성별 분석결과, 전력 판매가능시간이 1시간 증가하는 것에 대한 한계지불의사액(MWTP, marginal willingness to pay)은 1,601,057원이었다. 그러나 잔존 전력량이 1% 감소 및 의무접속시간 1시간 증가에 대한 MWTP는 각각 -91,911원 및 -470,619원으로 분석되었다. 본 연구에서 도출한 V2G 시스템에 대한 정량적인 소비자 선호 정보는 향후 V2G 시스템 도입 및 관리정책에 유용하게 활용될 수 있다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.417-420
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• 2002

Recent works in the area of multimedia studies focus on a wide range of issues from the impact of multimedia on culture to its impact on economics and anything in between. The interconnectedness of the issues raised by this new practice is complicated by the fact that media are rapidly converging: in a very real way, multimedia is becoming a media prism that reflects the way in which media continually influence each other across disciplines and cultural borders. Thus, the impact of multimedia reflects a complicated crossroads where media, human experience, culture and technology converge. An effective design is generally based on shaping aesthetics for function and utility, with an emphasis on ease of use. However, in designing for cyberspace, it is possible to create narratives that challenge the interactor by encoding in the design an instructional aspect that teaches new approaches and forms. Such a design offers an equally aesthetic experience for the interactor as they explore the meaning of the work. This design approach has been used constructively in many applications. The crucial concern is to determine how little or how much information must be presented for the interactor to achieve a suitable level of cognition. This is always a balancing act: too much difficulty will result in interactor frustration and the abandonment of the activity and too little will result in boredom leading to the same negative result In addition, it can be anticipated that the interactor will bring her or his own level of experiential cognition and/or accretion, to the experience providing reflective cognition and/or restructure the learning curve. If the design of the application is outside their present experience, interactors will begin with established knowledge in order to explore the new work. Thus, it may be argued that the interactor explores, learns and cognates simultaneously based on primary experiential cognition. Learning is one of the most important keys to establishing a comfort level in a new media work. Once interactors have learned a new convention, they apply this cognitive knowledge to other new media experiences they may have. Pierre Levy would describe this process as a "new nomadism" that creates "an invisible space of understanding, knowledge, and intellectual power, within which new qualities of being and new ways of fashioning a society will flourish and mutate" (Levy xxv 1997). Thus, navigation itself of offers the interactors the opportunity to both apply and loam new cognitive skills. This suggests that new media narrative strategies are still in the process of developing unique conventions and, as a result, have not reached a level of coherent grammar. This paper intends to explore the cognitive aspects of new media design and in particular, will explore issues related to the design of new media interfaces. The paper will focus on the creation of narrative strategies that engage interactors through loaming curves thus enhancing interactivity.vity.