• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1553-1571
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• 2018

Currently, many of schemes for smart grid data aggregation are based on a one-level gateway (GW) topology. Since the data aggregation granularity in this topology is too single, the control center (CC) is unable to obtain more fine-grained data aggregation results for better monitoring smart grid. To improve this issue, Shen et al. propose an efficient privacy-preserving cube-data aggregation scheme in which the system model consists of two-level GW. However, a risk exists in their scheme that attacker could forge the signature by using leaked signing keys. In this paper, we propose a secure and fine-grained electricity consumption aggregation scheme for smart grid, which employs the homomorphic encryption to implement privacy-preserving aggregation of users' electricity consumption in the two-level GW smart grid. In our scheme, CC can achieve a flexible electricity regulation by obtaining data aggregation results of various granularities. In addition, our scheme uses the forward-secure signature with backward-secure detection (FSBD) technique to ensure the forward-backward secrecy of the signing keys. Security analysis and experimental results demonstrate that the proposed scheme can achieve forward-backward security of user's electricity consumption signature. Compared with related schemes, our scheme is more secure and efficient.

• Korean Journal of Community Nutrition
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• v.15 no.2
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• pp.169-179
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• 2010

Good snack consumption behaviors are important among elementary students because snack provides additional energy and nutrients and because good dietary behaviors should be formed during early stages of life. This study investigated, among elementary school students, 1) snack consumption behaviors, 2) snack-related nutrition knowledge level, and 3) relationships between snack behaviors and snack-related nutrition knowledge. A convenience sample (N = 372), drawn from 5th and 6th graders of an elementary schools in Siheung-si, Gyeonggi-do, completed a pre-tested questionnaire. More than 85% of the participants snacked more than once per week. Most (77%) had their snacks at home. Fruit and fruit juice were the most frequently consumed and the most liked snack items. Taste was the most important in choosing a snack item closely followed by health/nutrition. Snack-related knowledge level was relatively high and the participants obtained their nutrition knowledge through mass media (30.4%) and family/friends (29.0%). Snack-related nutrition knowledge level and snack consumption behaviors showed positive relationships in various areas such as choosing more nutritious snack items and checking nutrition labels. Although this study was limited by its cross-sectional study design, these positive relationships suggest that better nutrition knowledge could result in better behaviors. Results of this study indicated that factual nutritional knowledge has been well transmitted to students. Therefore, future nutrition education on snacking could focus more on providing problem-solving and operational knowledge.

• Journal of the Korean Home Economics Association
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• v.18 no.1
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• pp.67-82
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• 1980

The objectives of the study were to determine 1) energy uses for residential requirements, 2) if energy consumption and adoption of energy conservation attitudes and practices vary with independent variables family size, stage of family life cycle, homemaker's level of education, income, heating system, and number of electrical household items, and 3) if there is a correlation between energy conservation attitudes and practices. Questionnaires were given to the randomly selected homemakers I Seoul in the summer (September, 1979) and the winter (February, 1980). Analysis of variance and correlation were used to analyzed the data which consisted of 537 usable responses of 895 returned in the summer and 554 responses of 794 returned in the winter. The results are as follows: 1) The order of consumption rate of the direct energy uses for residential requirements was found to be heating and air conditioning, cooking, refrigeration, T.V., lighting, and miscellaneous. 2) Energy consumption and adoption of energy conservation attitudes and practices were significantly related to family size, homemaker's level of education, and the stage of family life cycle. (1) Families of five members revealed higher scores in attitudes and practices than families less than five or more than six. (2) The higher the homemaker's level of education, the more energy consumption and the higher scores I attitudes and practices were found. (3) Families in the middle stage of family life cycle tend to use more energy than younger or older families, but their scores in attitudes and practices were high. 3) There was a significant correlation between energy conservation attitudes and practices. However, the scores of the conservation practices were not as good as the attitudes. It may be attributed to either a lack of knowledge and/or financial difficulties, or a dissonance between the concept and implementation of energy conservation. 4) Recommendations for the energy-saving and energy-related public policies are: (1) to use such human resources as attitudes, values, feelings of agreement, and cooperation, as well as nonhuman resources for the energy conservation, (2) to develop a educational program and a creative system I order to implement energy conservation programs, and (3) to consider direct as well as indirect energy uses I selecting goods and services.

• Journal of Dairy Science and Biotechnology
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• v.24 no.2
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• pp.11-20
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• 2006

Korea dairy industry has a long and chronic problems to consume raw milk , those are surplus milk and decline the market milk consumption continued about 10 years. This study was aim to propose and to find the solution for dairy industry problems. After WTO system, with the importation of dairy products, domestic milk production has fell into the situation of excess supply and huge inventory of dried milk, the milk powder stocks have increased since 2002. That made a chronic decline milk consumption in Korea. The core of chronic problem of Korea dairy industry is the decreasing in market milk consumption. If they have a settlement of any other way using their raw milk to process and consumption to market milk, there will be a solution to solve the chronic problems in this situation. Especially, that will be a development of small farm scale natural cheese production and consume. This may be lead a situation of increase the raw milk consumption, because natural cheese making needs much of raw milk more than market milk. But there are very low technical level of farmers cheese making status, so they need a cheese making educational program for their commercial level of cheese products. Under these situation, there are needed a way out of educational system for the dairy farmers to obtain the high level of cheese making technology from the trustable and scientific organization. The natural cheese making technique of dairy farmers should be accumulated to get the consumers' solid recognition of high quality of natural cheese as LOHAS(Lifestyle Of Health And Sustainability) foods.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.12
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• pp.724-735
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• 2003

In recent high-performance superscalar processors, the result value of an instruction is predicted to improve instruction-level parallelism by breaking data dependencies. Using those predicted values, instructions are speculatively executed and substantial performance can be gained. It, however, requires additional power consumption due to the frequent access and update of the value prediction table. In this paper, first, the trade-off between the performance improvement and the increased power consumption for value prediction is measured and analyzed. And, in order to reduce additional power consumption without performance loss, the technique of controlling speculative execution with confidence counter and predicting useful instructions is developed. Also, in order to prove the validity, a tool is developed that can simulate processor behavior at cycle-level and measure total energy consumption and power consumption per cycle.

• Korean Journal of Community Nutrition
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• v.6 no.5
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• pp.789-797
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• 2001

This study was conducted to find the differences in food consumption frequency of the middle aged(male 20, female 50) and the elderly(male 15, female 15) living in Chonju in December, 1998 according to food habits, smoking, alcohol drinking and exercising habit, health status, and the levels of nutrition knowledge and attitude store. The foods frequently consumed among the subjects were kimchi(15.4/week), mixed rice(11.5/week), rice(7.6/week), vegetables in soup, jjigae and jorim(5.0/week), mandarins and oranges(5.e/week), and seasoned laver(4.3/week). There were several factors influencing food consumption patterns. These were age, regularity of meal times, the status of smoking, alcohol drinking and exercising, and the level of nutrition attitude. The elderly ate cooked rice more frequently, while the middle aged ate fish, especially blue fishes more frequently. The middle aged who had breakfast regularly ate milk and milk products, legumes and fruits frequently. Those who smoked seemed to eat less cereals and starches and fats, while those who didn't smoke ate more sugars. The alcohol drinking group also ate less fats and the exorcising group ate almost all of food groups frequently. The status of health showed to be related with food consumption patterns. The normal group in hemoglobin ate eggs more frequently than the anemia group and the high risk group in blood pressure ate almost all of food groups more frequently. The high level group for nutrition attitude score chose vegetables, fruits, and milk and milk products more frequently than the other groups. On the other hand, low level group for nutrition attitude score was apt to eat ramyun, ham-sausage, and carbonated beverages more frequently. Therefore, nutrition education to improve the food habits find to change nutrition attitude is necessary to promote health status anti mole attention should be taken to the high risk group in blood pressure to guide proper food and nutrition intakes.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.12
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• pp.1008-1012
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• 2009

Obfuscation is known as one of the most effective methods to protect software against malicious reverse engineering transforming the software into more complicated one with still preserving the original semantic. However, obfuscating a program can increase both code size of the program and execution time compared to the original program. In mobile devices, the increases of code size and execution time incur the waste of resources including the increase of power consumption. This paper has analyzed the effectiveness of some high-level obfuscation algorithms as well as their power consumption with implementing them under an embedded board equipped with ARM processor. The analysis results show that there is (are) an efficient obfuscation method(s) in terms of execution time or power consumption according to characteristics of a given program.

• Nutrition Research and Practice
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• v.9 no.5
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• pp.503-510
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• 2015

BACKGROUND/OBJECTIVES: Increased serum homocysteine (Hcy) levels have been reported to be related to the occurrence of cardio- and cerebrovascular diseases. High serum Hcy levels are also related to the development of secondary stroke and all-cause mortality. The purpose of this study was to investigate the prevalence of high serum homocysteine level and relating factors, and the change over the 10 month period post-stroke. SUBJECTS/METHODS: Consecutive stroke patients who were admitted to the Asan Medical Center were enrolled. Ten months after the onset of stroke, an interview with a structured questionnaire was performed and blood samples were obtained for the biochemical parameters. Nutritional status was determined using the mini nutritional assessment (MNA) score and dietary nutrient intakes were also obtained using a 24 hour recall method. RESULTS: Out of 203 patients, 84% were malnourished or at risk of malnutrition, and 26% had high homocysteine levels at 10 months post-stroke. Using logistic regression, the factors related with high homocysteine levels at 10 months post-stroke included heavy alcohol consumption (P = 0.020), low MNA scores (P = 0.026), low serum vitamin $B_{12}$ (P = 0.021) and low serum folate levels (P = 0.003). Of the 156 patients who had normal homocysteine levels at admission, 36 patients developed hyperhomocysteinemia 10 months post-stroke, which was related to heavy alcohol consumption (P = 0.013). Persistent hyperhomocysteinemia, observed in 22 patients (11%), was related to male sex (P = 0.031), old age (P = 0.042), low vitamin $B_6$ intake (P = 0.029), and heavy alcohol consumption (P = 0.013). CONCLUSION: Hyperhomocysteinemia is common in post-stroke, and is related to malnutrition, heavy alcohol drinking and low serum level of folate and vitamin $B_{12}$. Strategies to prevent or manage high homocysteine levels should consider these factors.

• Journal of Family Resource Management and Policy Review
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• v.16 no.1
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• pp.85-101
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• 2012

This study aims to identify the propensity to consume and housing characteristics according to life cycle as the main independent variable. It also tries to understand the consumption power and housing style of each cycle and analyze whether there are differences between each life cycle, ultimately aiming to match the propensity to consume and housing style with each cycle. For empirical analysis, on and off-line surveys of 488 people were collected and analyzed by cross analysis, factor analysis and analysis of variance. The prime research findings are as follows: First of all, factor analysis on propensity to consume showed four main sub-factors as rational consumption, conspicuous consumption, trend consumption, and status consumption. Secondly, current and preferred housing styles ranked from modern, natural, casual, classic and romantic, which proved that people are currently housed in preferred housing styles. Thirdly, in case of housing-related characteristics of life cycles, the size of the house increased as the levels progressed, and then decreased at level 6 when the children grew into adulthood. The majority of the population was paying a monthly rent, a few were leasing, and a very few owned their housing. 58% were living in apartments, but in levels 1-2, more were living in row houses and high-rise residential buildings, while in level 6 it was detached houses. Fourthly, the propensity to consume according to life cycle tended to shift from conspicuous and trend-based consumption to rational consumption as the cycles progressed. Fifthly, the preferred housing styles were modern and natural styles, regardless of life cycle. These study results can be applied to product development and marketing activities based on their accurate analysis of customers' needs, which can thus bring further customer satisfaction.

• Asian Journal of Atmospheric Environment
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• v.8 no.1
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• pp.48-58
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• 2014

Energy efficiency is vital to improve energy security, environmental and social sustainability, and economic performance. Improved energy efficiency also mitigates climate change by lowering greenhouse gas (GHG) emissions. Buildings are the single largest industrial consumer of energy and are therefore key to understanding and analyzing energy consumption patterns and the opportunities for saving energy at the district level in urban environments. This study focused on two representative boroughs in the major metropolitan area of Seoul, South Korea as a case study: Gandong-gu, a typical residential district, and Jung-gu, a typical commercial district. The sources of the energy supplied to the boroughs were determined and consumption patterns in different industry sectors in Seoul used to identify current patterns of energy consumption. The study analyzed the energy consumption patterns for five different building categories and four different sectors in the building using a bottom-up energy modeling approach. Electricity and gas consumption patterns were recorded for different building categories and monthly ambient temperatures in the two boroughs. Finally, a logarithmic equation was developed to describe the correlation between commercial activity and cooling energy intensity in Jung-gu, the commercial district. Based on these results, recommendations are made regarding the current energy consumption patterns at the district level and government energy policies are suggested to reduce energy consumption and, hence, greenhouse gas emissions, in both commercial and residential buildings.