• Journal of Communications and Networks
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• 제9권3호
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• pp.265-273
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• 2007

This paper expands an analytical performance model of 802.11 to accurately estimate throughput and energy demand of 802.11-based wireless sensor network (WSN) when sensor nodes employ Reed-Solomon (RS) codes, one of block forward error correction (FEC) techniques. This model evaluates these two metrics as a function of the channel bit error rate (BER) and the RS symbol size. Since the basic recovery unit of RS codes is a symbol not a bit, the symbol size affects the WSN performance even if each packet carries the same amount of FEC check bits. The larger size is more effective to recover long-lasting error bursts although it increases the computational complexity of encoding and decoding RS codes. For applying the extended model to WSNs, this paper collects traffic traces from a WSN consisting of two TIP50CM sensor nodes and measures its energy consumption for processing RS codes. Based on traces, it approximates WSN channels with Gilbert models. The computational analyses confirm that the adoption of RS codes in 802.11 significantly improves its throughput and energy efficiency of WSNs with a high BER. They also predict that the choice of an appropriate RS symbol size causes a lot of difference in throughput and power waste over short-term durations while the symbol size rarely affects the long-term average of these metrics.

• KIEAE Journal
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• 제13권6호
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• pp.55-65
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• 2013

Korean Government has developed Sejong City as a new administration city. This city of future was planned and designed toward one of the most eco-friendly city on the basis of ICTs. To attain this object, a carbon emission monitoring system (CEMS) was designed and installed as a part of u-city service which provides various information anytime and anywhere to enrich the people's quality of life. In this paper, at first, the structure and functions of CEMS are introduced. This system is consist of 5 parts - data collection from user and linked public DBs, transforming data into meaningful information for the policy makers, system-user interfacing via statistical tables and graphs, and system maintenance. This system can be operated by the citizen participation through whole the process. With the help of GIS map and graphic interface, statistics of monitored data for both citizen and decision maker provided and after feed-back, they have affected on the behaviour of citizen's energy consumption and related policy as well. By the CEMS, energy consumption data of 124 agreed households were collected during 9 months in 2012. Electricity, gas and water consumption were remote-metered automatically by the system and analysed. This showed that more than 85% of CO2 emission is rely on electricity usage. Furthermore, number of family members and size of house influences on the emission of CO2 by each household together with the life-style of the occupants. Electricity and water consumption showed the seasonal factor while gas consumption represents the number of family members. Even this paper has limitations caused by 9 months of data collection, it shows the policy directions to reduce the emission of CO2 focusing on the house size and number of family members of each households. With the result of this research, life-style of the generation of dwellers should be investigated and the CO2 emission characteristics of other housing type as well for the data building for future policy making.

• 한국식품과학회지
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• 제15권3호
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• pp.282-286
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• 1983

통조림 살균에서 에너지의 효율적인 사용을 위하여 열전달형태, 살균온도, 가공공관, 살균방법등의 요인에 따른 에너지 소비를 검토한 바 고온(高溫)에서 소형관형으로 살균할 때가 적은 에너지가 소비되고 있으며, 이러한 차이는 대류형(對流型) 열전달식품(熱傳達食品)보다 전도형(傳導型) 열전달식품(熱傳達食品)의 살균(殺菌)에 현저하였다. 열수살균으로는 증기살균에 비해 전도형 식품의 살균에 적은 에너지를 소비하였으나, 대류형 식품에서는 효과적이지 못하였다. 본 실험에서의 여러 조건별 에너지 소비 data는 현장에서의 에너지 소비예측, 에너지 사용설계 등의 여러목적에 적용될 수 있는 것으로 판단된다.

• 가정과삶의질연구
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• 제26권2호
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• pp.83-101
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• 2008

This research performs a multi comparison between the age of old households and the economic structure according to accommodation type as well as analyzing the economical structural difference of each type based on the features of aged households. The paper classified aged households into 3 groups according to age distribution. The economic structure analysis according to the age of old households and accommodation type was shown as follow: First, the economical structural analysis based on the age of old households showed a statistical difference in the total, labor, business, property and transfer income variables according to the age of each sample group. However, the non-business income and liabilities did not show a significant difference. Second, in the analysis of different economic earnings and initial expenses of middle-aged households according to the age distribution group showed a disparity in the total, labor, business, property, and transfer income variables according to the age of each sample group. However, aged households showed a statistical difference in total, labor, business and transfer income variables. Third, in the analysis of difference in the expense provision and size of consumption, there was a statistical difference in the expense variables of total consumption, food, dining out, electricity, water, furniture, kitchen supplies, clothing, shoe, education, culture, entertainment, transportation, and communication. Fourth, in the analysis of difference in the size of consumption expense, the initial and middle-aged households showed a statistical difference in the total consumption, food, dining out, electricity, water, furniture, kitchen supplies, clothing, shoe, education, culture, entertainment, transportation, communication, and consumption expense variables. However, the analysis of aged households has shown a statistical difference in the total consumption, food, dining out, electricity, water, furniture, kitchen supplies, clothing, shoe, education, culture, entertainment, transportation, and communication expense variables. The study found a statistical difference in the expense for hygienics that did not appear in the initial and middle-aged households.

• 한국식생활문화학회지
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• 제34권5호
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• pp.595-603
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• 2019

This paper provides data for product development and improvement of grape varieties by analyzing the satisfaction-importance of the grape selection attributes from a consumer's perspective. A survey was conducted on consumers aged 19-59 living in Seoul, Gyeonggi and Incheon on their fruit consumption level, preferences according to the grape quality characteristics, importance, and satisfaction with the grape selection attributes. Three hundred and eighty two valid samples were collected and analyzed statistically using SPSS 23. In the preference according to the grape quality characteristics, consumers tended to prefer a sweet taste, black color, and seedless grapes. Regarding the importance of the grape selection attributes according to the level of grape consumption, the high consumption group considers texture, size, shape, color, ease of removing seeds, country of origin, area of production, certification, and brand to be more important. In satisfaction, the high consumption group rated satisfaction highly in texture, odor, size, shape, color, ease of removing peelings, ease of removing seeds, price, country of origin, area of production, certification, and brand. An analysis of the IPA of the grape selection attributes showed that improvement of price and shape attributes will be prioritized, and the development and management of properties, such as seeds, peelings, certification, and brand will be required. These results can be used to help improve the grape varieties and develop products that meet the consumer needs, secure the competitiveness of grape farmers, and revitalize the local economy.

• Nutrition Research and Practice
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• 제16권4호
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• pp.489-504
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• 2022

BACKGROUND/OBJECTIVES: This study examined socio-economic differences in diverse food consumption among children 6-23 months of age in South Asia and Southeast Asian countries. SUBJECTS/METHODS: Data from Demographic and Health Surveys in four countries in South Asia (n = 15,749) and four countries in Southeast Asia (n = 10,789) were used. Survey-design adjusted proportions were estimated for the following 10 food items: grains, legumes, dark green leafy vegetables (DGLV), vitamin A-rich fruits, vitamin A-rich vegetables, other fruits and vegetables (OFV), fish, meat, dairy, and eggs. An equity gap was defined as an arithmetic difference in the proportion of each food item consumed in the past 24-hours between the wealthiest and lowest quintiles and between rural and urban areas, denoted by percentage points (pp). RESULTS: The consumption of most of the 10 food items was higher in the wealthiest quintiles and urban areas across eight countries. The size of equity gaps was greater in Southeast Asia than in South Asia, particularly for vitamin A-rich fruits (3.3-30.0 pp vs. 0.3-19.6 pp), vitamin A-rich vegetables (12.1-26.7 pp vs. 2.4-5.9 pp), meat (17.7-33.4 pp vs. 3.4-13.4 pp), and dairy (14.7-32.5 pp vs. 3.3-11.4 pp). However, the size of equity gap in egg consumption was greater in Southeast Asia than South Asia (11.2-19.8 pp vs. 11.0-26.7 pp). Relatively narrower gaps were seen in the consumption of grains (0.3-12.9 pp), DGLV (0.6-12.4 pp), and fish (0.1-16.8 pp) across all countries. CONCLUSIONS: Equity gaps in food consumption differed by socio-economic status and region. Reducing equity gaps in nutrient-rich foods and utilizing regionally available food resources may increase child dietary quality.

• KDI Journal of Economic Policy
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• 제38권4호
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• pp.23-44
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• 2016

Household debt in Korea raises concerns about the resilience of the economy due to its size and quality. Against this backdrop, we investigate if household leverage matters for private consumption in adverse economic environments even without severe financial disruptions. We find that the balance sheet positions in terms of the leverage ratio may weaken consumption growth. We also find that the depressive effect of debt on consumption may differ across types of consumer spending and household characteristics. In particular, the effects of indebtedness have been much stronger in relation to durable goods expenditures than in other areas. In addition, debtors in high-income (wealth) groups have also shown downward adjustments in consumption even more so than low-income (wealth) groups. These findings imply that debtors' precautionary behavior may serve as an important channel from leverage to consumer spending.

• 환경생물
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• 제30권4호
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• pp.349-354
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• 2012

To evaluate the biological response of sea squirt Halocynthia roretzi with different body size to heavy metals and its suitability for ecotoxicity assays, the effects of Cr, Cu and Zn on its clearance and oxygen consumption rates were investigated. Clearance and oxygen consumption rates of H. roretzi with various body sizes were calculated at different metal concentrations. Both clearance and oxygen consumption rate were negatively correlated with body sizes. Clearance rate of H. roretzi decreased gradually with increasing concentration of heavy metal, the decreasing rate was in an order of Cr>Cu>Zn. The oxygen consumption rate first increased at low metal concentration (below $100{\mu}g\;L^{-1}$) and then decreased rapidly with increasing metal concentrations. The decreasing rate was in an order of Cu>Cr=Zn. There was a trend that the clearance rate and oxygen consumption rate decreased drastically under a concentration of $400{\mu}g\;L^{-1}$, and then decreased smoothly when the metal ion concentration increased continually. So the oxygen consumption and clearance rate at a concentration of $400{\mu}g\;L^{-1}$ Cu could be thought as a suitable biological tool for exotoxicology analysis.

• 한국조리학회지
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• 제23권2호
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• pp.64-73
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• 2017

본 연구에서는 국민건강영양조사의 식품섭취빈도 조사로부터 식품섭취빈도를 산출한 후 이를 24시간 회상법에서 조사된 식품별 섭취량과의 상관관계를 탐색하여 식품 수준의 일상 섭취량을 추정할 때 식품섭취빈도를 공변수의 형태로 활용할 수 있을지 타진해 보기 위해 수행되었다. 국민건강영양조사에서 식품섭취빈도 조사가 수행되기 시작한 2012년부터 2014년까지 총 3개년도의 자료를 사용하였으며, 24시간 회상법과 식품섭취빈도 조사 모두를 수행한 10,945명을 대상으로 하였다. 분석을 위해 식품섭취빈도 조사지에 수록된 112개 항목별로 24시간 회상법에서 산출된 식품별 섭취량을 재산출하였으며, 이 결과와 각 개인이 식품섭취빈도 조사법에서 응답한 섭취빈도 및 섭취분량 간의 스피어만 상관계수를 산출하였다. 상관계수를 분석한 결과, 24시간 회상법의 섭취량과 식품섭취빈도법의 섭취빈도 간에는 총 112개 식품 중 59개 식품(52.2%)에서 통계적으로 유의한 양의 상관관계를 보였으며, 24시간 회상법의 섭취량과 섭취분량 간에는 102개 식품(90.3%)에서 통계적으로 유의한 양의 상관관계를 보였다. 곡류, 과일류, 난류, 두류, 생선류, 서류, 우유류, 육류, 음료류, 주류, 채소류, 해조류, 기타류의 13개 식품군으로 묶어 분석한 결과에서도 섭취빈도의 13개 군(100%)에서 통계적으로 유의한 상관관계를 보였으며, 생선류, 해조류, 기타류는 음의 상관을 보였고, 나머지 10개 항목은 양의 상관을 보였다. 본 연구를 통해 식품섭취빈도조사로부터 산출한 식품섭취빈도와 24시간 회상법 섭취량간의 일관된 상관관계를 확인할 수 있었으며, 이는 식품(군) 수준의 일상 섭취량을 추정할 때 식품섭취빈도를 중요한 공변수로 활용할 수 있는 근거가 된다고 하겠다.

• 유통과학연구
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• 제16권9호
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• pp.79-99
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• 2018

Purpose - Food consumption in Korea has changed in paradigm as it has grown qualitatively in the past in quantitative shortages. Consumer food consumption patterns are rapidly changing due to changes in economic, social and population conditions, scientific and technological development, climate change, and market opening. At the same time, there is a need to actively respond to these changes in terms of the food industry, market, and government policy. The purpose of this study is to examine the changes and characteristics of food consumption expenditure of Korean consumers in-depth and depth in order to provide implications for agriculture, food market and policymakers. Research design, data, and methodology - We analyzed various food consumption changes from the 1980s to 2015 through Household Income and Expenditure Survey raw data from MDIS(Microdata Integrated Service) of Statistics Korea. and conducted the age effect, generation effect, and year effect by cohort analysis. We also conducted comparisons with OECD countries on several indicators. Results - Food consumption spending was slow, and there was no significant change in home consumption, while eating out consumption increased about 20 times in 2015 compared to 1980. Income, age, residential area, number of household members showed significant changes in food consumption. According to the cohort analysis, the changes in the food consumption structure are largely due to age effect, and the year, age, and generation effects are different for each food item. Conclusions - Food consumption has a significant impact on not only the nutritional status of consumers but ultimately the public health. Therefore, they should be regarded as a strategic policy area of central government rather than a matter of size and change of food consumption expenditure.