• 대한수학회보
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• 제61권2호
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• pp.479-488
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• 2024

Convergence to a steady state in the long term limit is established for global weak solutions to a chemotaxis model with degenerate local sensing and consumption, when the motility function is C¹-smooth on [0, ∞), vanishes at zero, and is positive on (0, ∞). A condition excluding that the large time limit is spatially homogeneous is also provided. These results extend previous ones derived for motility functions vanishing algebraically at zero and rely on a completely different approach.

• 대한지역사회영양학회지
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• 제21권2호
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• pp.140-151
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• 2016

Objectives: This study was performed to examine the consumption patterns of convenience food at convenience stores, dietary habits, and perception as well as knowledge of food additives among university students. Methods: Subjects were 352 university students in Cheongju, Korea, and data was collected by a self-administered questionnaire. They were divided into three groups according to the frequency of consumption of convenience food at convenience stores: 79 rare (${\leq}1$ time/month), 89 moderate (2-4 times/month) and 184 frequent (${\geq}2$ times/week). Results: More subjects from the frequent consumption group lived apart from parents (p<0.001) and possessed more pocket money (p<0.01). Frequent consumption group consumed noodles, Kimbab, and sandwich & burger significantly more often (p<0.001, respectively) than others. In addition, frequent consumption of convenience foods at convenience stores was associated with frequent breakfast skipping (p<0.05), irregular meal time (p<0.01), snacking (p<0.05), and eating late night meal (p<0.001). More from the rare consumption group had heard about food additives previously compared to the frequent consumption group (79.7% vs. 63.6%, p<0.01). Frequent consumption group showed significantly higher score than did the rare consumption group for the following questions: monosodium glutamate is harmful to your health (p<0.05), food additives are necessary for food manufacturing (p<0.005), food additives need to be labeled on products (p<0.05), there is no food additive at all if labeled as no preservatives, no coloring, and no added sugar (p<0.05). There was a significant difference in degrees of choosing products with less food additives depending on the consumption pattern. Conclusions: Our results provided a better understanding of the factors associated with frequent consumption of convenience foods at convenience stores among university students and will be useful to develop a nutrition education program for those who are more prone to consume convenience foods.

• 대한임베디드공학회논문지
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• 제2권3호
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• pp.164-173
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• 2007

In this paper, we present a time-triggered mechanism for providing energy consumption profiles in the level of C functions. The similar mechanisms have already been introduced at the previous researches such as PowerScope and ePRO. Instead, we, in this paper, introduce our efforts to extend these researches to incorporate power domains and DVS(Dynamic Voltage Scaling), then to provide GUI-based tool as a plug-in to ESTO which is an IDE for Embedded S/W development based on Eclipse. From our experimental results, we could conclude that our approach worked and produced consistent energy consumption profiles on the DVS-applied program codes, and also displayed function level and time domain power consumption information with diverse presentation skills such as tables, phi-chart, bar-chart, 2-D graphs, consequently, is expected to provide more ease-to-use and productive IDE for lower power embedded S/W developers.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권4호
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• pp.626-648
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• 2011

Energy consumption of wireless access networks is in permanent increase, which necessitates development of more energy-efficient network management approaches. Such management schemes must result with adaptation of network energy consumption in accordance with daily variations in user activity. In this paper, we consider possible energy savings of wireless local area networks (WLANs) through development of a few integer linear programming (ILP) models. Effectiveness of ILP models providing energy-efficient management of network resources have been tested on several WLAN instances of different sizes. To cope with the problem of high computational time characteristic for some ILP models, we further develop several heuristic algorithms that are based on greedy methods and local search. Although heuristics obtains somewhat higher results of energy consumption in comparison with the ones of corresponding ILP models, heuristic algorithms ensures minimization of network energy consumption in an amount of time that is acceptable for practical implementations. This confirms that network management algorithms will play a significant role in practical realization of future energy-efficient network management systems.

• 가정과삶의질연구
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• 제10권2호
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• pp.19-36
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• 1992

The purpose of this paper is to analyze empirically the tendency of household consumption expenditure according to the change of social and economical condition, and the factor which influences consumption expenditure of urban household. The data used in analysis are time-series. The data are statistic form Urban Household Economy Survey published by the Economic Planning Board, dating form the first quarter of 1970 to the fourth quarter of 1989. The income of household and consumption expenditure materials were deflated as consumer price index to exclude the influence of prices and the influence of household composition are considered to deflated as the size of the household under assumption of homogeneity. The consumption expenditure items were categorized to 12 relatively large range items. The time-series data were analyzed by using the Two Stage Least Squares and the Ordinary Least Squares. The following is the result of analysis. 1) Rather than the income increase of previous years. the average income increase for two years influences more significantly on consumption expenditure of household. In the case of influence on consumption expenditure for each item by increase in disposable income, such categories as furniture and utensils. clothing and footwear, housing, medical care, culture and recreation, and transportation and communication have significant influence. 2) Among consumption expenditure categories, the increasing factors were furniture and utensils, and clothing and footwear. And the decreasing factors were housing, medical care, culture and recreation ,and transportation and communication. The relative prices, however, had significant influence on categories such as housing, furniture and utensils, medical care , culture and recreation, and transportation and communication and all of them were the decreation factors. 3) Among with changes of social and economical conditions, miscellaneous showed the highest increase in marginal propensity to consume and foods was the lowest. Also culture and recreation and housing brought up a great change of the income elasticity of demand.

• Asian Journal of Business Environment
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• 제2권2호
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• pp.23-26
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• 2012

Purpose - The study on the consumption structure of urban residents can help us to understand demand law and to grasp the changing consumption trend of people. Consumption structure is an important indicator reflecting the people's living standard. It is of realistic significance to study urban consumption structure. Research data and methodology - This study is carried out with data connected with urban residents from Shandong Statistical Yearbook for the period 2000-2010 analyzing eight commodity groups. The almost ideal demand system (AIDS) is one of the important models related to consumption structure. Results - This paper shows that firstly gives a brief introduction to AIDS. Then it makes an empirical analysis on the urban residents' consumption structure in Shandong province, China on the basis of AIDS model. Conclusions - the authorities are supposed to control the prices of HC, Foodstuff and Housing and encourage the consumption of HC, Housing, EE accordingly. At the same time, local government should increase the supply of goods connected with housing, HA, HC, and EE so as to attract more consumption from the urban residents in Shandong.

• 가정과삶의질연구
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• 제17권1호
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• pp.33-44
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• 1999

This study investigates the importance of the role of mother to reduce conspicuous consumption of adolescent consumers. This study analyzes that the socio-demographic variables of adolescent consumers consumer ability the degree of materialism and the level at which the conspicuous consumption of the mother affect the conspicuous consumption of adolescent consumers. Analysis of the data collected from this study will be used to assist in reducing conspicuous consumption of adolescent consumers. A survey was conducted by questionnarire with 597 adolescent consumers attending middle and high school located in Seoul and their mothers. The results of this study show that the effect of conspicuous consumption of the mother was the most significant factor on the conspicuous consumption of adolescent consumers. The following factors were correlated with higher conspicuous consumption levels in adolescent consumers: 1) higher level of conspicuous consumption of the mother: 2) a lower evel of the moths consumer attitude ; 3) the lower educational level of the mother ; 4) whether the mother worked outside of the home rather than stayed at home full-time; and 5) less household income.

• 오토저널
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• 제6권4호
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• pp.36-45
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• 1984

The relationship between vehicle driving pattern and fuel consumption in urban area was studied in Seoul along three representative routes using a test car equipped with all the instruments required for recording modes of traffic and measuring fuel consumption. Correlation with idle speed, fuel consumption and CO concentration of car in use was also measured. The average vehicle speed in Seoul was 31.4 km/h and the time spent in different modes was 23.0% in idle mode, 22.5% in acceleration mode, 32.4% in cruising mode and 22.3% in deceleration mode, respectively. Hence, traffic flow was suggested to be relatively smooth. Fuel consumption per unit distance, .phi. was closely related with trip time spent per unit distance, t, and correlation coefficient obtained from the test car was 0.925, and the relationship between .phi. and t was also obtained from the linear regression with the following equation. .phi.=42.87+0.38 t. Idle speed of vehicle in use was mostly adjusted low and cars which were over the permissible standard of CO concentration (4.5%) were 50% or more. As the idle speed decreased, the fuel consumption was decreased, while the CO concentration was increased. Therefore, the decrease of fuel consumption can not be expected with only a decrease in idle speed.

• 한국산업융합학회 논문집
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• 제21권5호
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• pp.207-217
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• 2018

Recently, the importance of energy demand management, particularly peak load control, has been increasing due to the policy changes of the Second Energy Basic Plan. Even though the installation of distributed generation systems such as Photovoltaic and energy storage systems (ESS) are encouraged, high initial installation costs make it difficult to expand their supply. In this study, the power consumption of a university building was measured in real time and the measured power consumption data was used to calculate the optimal installation capacity of the Photovoltaic and ESS, respectively. In order to calculate the optimal capacity, it is necessary to analyze the operation methods of the Photovoltaic and ESS while considering the KEPCO electricity billing system, power consumption patterns of the building, installation costs of the Photovoltaic and ESS, estimated savings on electric charges, and life time. In this study, the power consumption of the university building with a daily power consumption of approximately 200kWh and a peak power of approximately 20kW was measured per minute. An economic analysis conducted using these measured data showed that the optimal capacity was approximately 30kW for Photovoltaic and approximately 7kWh for ESS.

• 한국인터넷방송통신학회논문지
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• 제18권1호
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• pp.37-41
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• 2018

본 논문에서는 참고문헌[1] 논문에서 제안한 고유의 링크 스케줄링 방법이 적용된 IEEE802.15.4e TSCH (Time-Slotted Channel Hopping)의 전력 소비 측면에서 절감 능력을 기존 단일채널 IEEE802.15.4와 비교하여 분석한다. TSCH 방식이 기존 방식에 비해 어떤 트래픽 조건하에서도 전력소모가 적게 하는 것으로 나타난다. 그 이유는 첫째, 충돌이 발생하지 않는 스케줄링 방식으로 인해 백오프 시간이 없다는 점과 둘째, MAC 오프셋 시간변수들의 차이로 인한 것으로 판단된다. 마지막으로 TSCH에서는 디바이스들은 자신의 스케줄이 아닌 타임 슬롯 동안은 sleep을 통해 전력 소모를 줄일 수 있음을 볼 수 있다.