• Progress in Superconductivity
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• 제13권1호
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• pp.1-6
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• 2011

Measurement of magnetic signals generated from electric activity of myocardium provides useful information for the functional diagnosis of heart diseases. Key technical component of the magnetocardiography (MCG) technology is SQUID. To measure MCG signals with high signal-to-noise ratio, sensitive SQUID magnetic field sensors are needed. Present magnetic field sensors based on Nb SQUIDs have field sensitivity good enough to measure most of MCG signals. However, for accurate measurement of fine signal pattern or detection of local atrial fibrillation signals, we may need higher field sensitivity. In addition to field sensitivity, economic aspect of the SQUID system is also important. To simplify the SQUID readout electronics, the output voltage or flux-to-voltage transfer of SQUID should be large enough so that direct measurement of SQUID output can be done using room-temperature preamplifiers. Double relaxation oscillation SQUID (DROS), having about 10 times larger flux-to-voltage transfers than those of DC-SQUIDs, was shown to be a good choice to make the electronics compact. For effective cancellation of external noise inside a thin economic shielded room, first-order axial gradiometer with high balance, simple structure and long-baseline is needed. We developed a technology to make the axial gradiometer compact using direct bonding of superconductive wires between pickup coil and input coil. Conventional insert has mechanical support to hold the gradiometer array, and the dewar neck has equal diameter with the dewar bottom. Boiling of the liquid He can generate mechanical vibrations in the gradiometer array due to mechanical connection structure. Elimination of the mechanical support, and direct mounting of the gradiometer array into the dewar bottom can reduce the dewar neck diameter, resulting in the reduction of liquid He consumption.

• 한국농공학회논문집
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• 제62권5호
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• pp.27-37
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• 2020

As domestic meat consumption increases, the broiler production industry has been larger and denser. The concentration of particulate matter (PM) and harmful gases generated is also increasing inside livestock house. However, the current research status of PM exposed to farm workers and the health effects are in the early stage. To understand PM concentration affecting workers in the broiler house, field monitoring was conducted according to its size distributions. Concentrations of PM₁₀, PM_2.5, and TD (Total Dust) were monitored using personal air samplers with teflon filter during working and moving periods considering the ventilation systems of 6 broiler houses. The purpose of this study is to monitor the PM concentration in the experimental broiler houses operated by forced ventilation system generally used in Korea and to evaluate the regional concentrations through airflow pattern. The PM concentrations were increased from inlet to outlet vents resulting in 1,872 of TD, 1,385 of PM₁₀, and 209 ㎍/㎥ of PM_2.5, respectively. The TD and PM₁₀ concentrations were increased when the workers and broilers were moving. Among them, the particle size that occupied the largest amount of PM was 13.75 ㎛. These results suggest that personal protection equipments are important to reduce the health effect from PM inhalation.

• 한국자동차공학회논문집
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• 제17권3호
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• pp.90-101
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• 2009

An objective of this study is to suggest a procedure to evaluate vehicle emissions regardless of the driving pattern. Field experiments using portable emission measurement system were conducted under the real world driving cycle. Standardized average for NOx, $CO_2$ emission and fuel consumption rates were calculated while the vehicle specific power distribution within each vehicle speed bin was taken into consideration. Composite emission factor and fuel economy, which were obtained based on the standardized average results and traffic statistics, showed good similarity to those acquired through the conventional chassis dynamometer tests qualitatively as well as quantitatively. Considering that a conventional method obviously has a limitation to reflect various characteristics of the real world, the new approach suggested in this study can be used as an alternative procedure to collect more specific data to establish the mobile emission factors.

• 패션비즈니스
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• 제2권4호
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• pp.69-78
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• 1998

The purpose of this study was to identify the variables which could characteristics the New Young Generation (NYG), to investigate the relationship between level of NYG characteristics and information searching related to underwear purchasing, and the differences level of the NYG characteristics according to demographic variables (sex, grade, major), and examine the casual relationships of demographic variables (sex, place of growing background, parent's education) and level of the NYG characteristics on information searching related to underwear purchasing. The subjects were 723 college students (female = 324, male=398) living in Seoul and Kyuggi were participated in this study. The NYG is limited to person who born after 1970's. The result of this study were as follows; 1. Five factors of New Young Generation oriented characteristics were identified; F.1 'Info-telecommunication(Info-Telecom)'; F.2 'Family and Marriage'; F.3 'Consumption pattern'; FA 'Self-centered (Individualism)'; F.5 Work/Career oriented. 2. The relationship between the NYG characteristics and information search in underwear purchasing were significanted. 3. In demographic variables, gender, grade, and major were partially significant differences. 4. In male students, the result of the casual relationship between demographic variables with NYG characteristics and the level of the NYG in underwear purchasing showed that grade, background of grownplace, level of parent's education were significanted the high level of info-telecom factor associated with higher grade, city-grown, higher level of parent's education. In conclusion, the result showed that the level of NYG characteristics was significant to male students and specially for grade older students. The background of parent's education level was the another important variables to predicting the NYG characteristics. Finally the higher the NYG characteristics, the more information search in underwear purchasing.

• 한국식생활문화학회지
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• 제19권4호
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• pp.447-459
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• 2004

Fortified foods are consumed widely in modem society according to increased concern on health oriented foods. This study investigated the patterns of vitamin-and/or mineral-fortified food use among 677 teenage students(13-18 years of age) in Chungnam province and Daejeon city in Korea using questionnaire. More than 63.7% of total subjects consumed more than one package of fortified foods belonged to more than three categories of five categories including sweets/biscuits, ramyons, beverages, milk and dairy products, and breads as a frequency of more than 1-2 times/week during previous three months prior to present survey. Consumption of fortified foods was higher in middle school students than in high school students(p<0.05), and in females than in females(p<0.001). Users of fortified foods took the snacks more often(p<0.001), and they tended to believe more positively that fortification can be helpful in health maintenance than did non-users. Users preferred vitamin C and Ca(calcium) as a fortified nutrient. Major fortified nutrients in fortified foods taken by users were various; vitamin B-complex and Ca from sweets/biscuits, Ca from ramyons, vitamin C and Ca from beverages, Ca and iron from milk and dairy products and breads. These results suggest that fortified foods are used commonly and are influenced by several factors among teenagers. Types of fortified nutrient, in fortified foods taken by subjects, are various and fortification is performed unspecifically. As a consequence both nutrition education and government regulation on fortified foods should be enforced to maximize the benefits and minimize the hazard of their use.

• 한국식생활문화학회지
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• 제20권5호
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• pp.499-507
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• 2005

The purpose of this study is to draw attention to the distinction of Korean food as well as to find ways to universalize Korean food. Not only does Korean food a big part of representing the Korean culture itself, the ingredients in the Korean food are extremely nutritious. The excellence in the ingredients has been verified through scientific studies over and over. Today, this is recognized widely by the food experts in the U.S. This study also points out some of the hurdles in universalizing Korean food. First of all, many people around the world are not aware of the positive aspects of the Korean food. There have been minimal efforts, if at all, to find ways to make fusion Korean food to be part of a world cuisine. The lack of research and development in the Korean food industry also does not help the situation much. Lastly, the limited knowledge of the actual people working in the food service sector regarding Korean food hinders the Korean food going universal. Currently, the food industry in the U.S. is quite favorable for Korean food to enter its markets to become part of the American cuisine. The Americans' appetite continues to change towards more healthy living leaning them naturally towards Asian food. For Korean food to become part of the American cuisine, the follow recommendations are given in the study: 1) Korean food must be localized, become a fusion cuisine; 2) standardize the cooking method; 3) change the focus to rice-centered trend food; 4) foster more Korean food experts; and, 5) promotion of strengthening food advertisements while increasing research and development. It is also important during this whole process, traditional Korean food be discovered and implemented to the overall food program in universalizing Korean food.

• 한국통신학회논문지
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• 제39A권10호
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• pp.579-584
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• 2014

본 논문에서는 패치형 ESPAR(Electronically Steerable Parasitic Array Radiator) 안테나를 이용한 빔 공간 MIMO(beamsapce mulitple input multiple output) 시스템을 제안한다. 기존의 모노폴 ESPAR 안테나의 경우 단일 RF 체인을 갖기 때문에 하드웨어의 비용과 RF회로의 전력 소모를 절감할 수 있는 장점을 가진다. 하지만 공간적 제약이 큰 휴대용 이동기기에 적용하기 문제점이 있다. 따라서 부피를 간소화 시키는 방법으로써 패치형 ESPAR 안테나를 설계하고 단일 RF 체인으로 MIMO 기술이 가능한 빔 공간 MIMO 시스템에서의 성능을 분석한다. 본 논문에서 설계한 패치형 ESPAR 안테나를 통해 빔패턴이 ${\pm}15$도의 앙각의 변화를 가지는 것을 확인하였고, 또한 이 ESPAR 안테나를 사용하여 빔 공간 MIMO 시스템을 구현하고 이 시스템의 BER 성능을 확인하였다.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2002년도 춘계학술대회 논문집
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• pp.356-360
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• 2002

산업의 발달과 더불어 CO, $H_2$S, S $O_2$등에 의한 대기오염이 심각해져 가스중독의 위험성이 고조되었을 뿐만 아니라, 생활수준의 향상으로 부탄(C$_4$ $H_{10}$)이나 프로판(C$_3$ $H_{8}$) 등의 폭발성 탄화수소계 가스들의 수요가 급증하는 가운데 가스폭발의 위험성이 대두되고 있다. 이에 대한 방비책으로 고감도 가스센서의 개발 뿐만 아니라 가스센서를 응용한 가스검출 및 가스식별 시스템의 개발이 시급한 실정이다. 본 연구에서는 반도체식 가스센서의 선택도에 대한 문제점을 개선하는 동시에 단일 센서신호의 드리프트에 대한 영향을 최소화하기 위해 반도체식 가스센서 어레이를 구성하고, 이로부터 검지된 가스별 입력 패턴데이터를 신경 회로망(neural network)에 적용함으로써 가스의 종류를 선택적으로 인식할 수 있는 가스인식 시스템을 개발하고자 한다.다.

• 한국콘텐츠학회논문지
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• 제20권1호
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• pp.217-232
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• 2020

본 연구의 목적은 e-커머스의 산업 생태계가 활성화 될 수 있도록 온라인유통산업 이해관계자들이 활용 가능한 e-커머스 활성화 요인과 관련된 선행연구를 정리하고, e-커머스 전문가들을 대상으로 FGI를 진행하여 요인별 중요도를 산출하는 데 있다. 이에 선행연구와 FGI를 통해 도출된 핵심요인을 권혁인(2010)의 3 Level Service Model을 바탕으로 하여 계층구조모델을 구조화하고, AHP 방법론을 활용하여 각 요인의 가중치를 도출하였다. 상위요인에서는 민간(0.542) > 공동(0.237) > 공공(0.222) 순으로 중요하게 나타났다. 하위요인에서는 가중치 내림차순으로 '검색서비스 개발(0.0970)' > '추천서비스 개발(0.0805)' > '소비자 니즈 분석(0.0534)' > '고객 소비 패턴 분석(0.0505)' > '타 플랫폼 연계 서비스 개발(0.0450)' 등으로 나타나 우선순위 15위 이내의 요인을 대상으로 각각의 시사점을 기술하였다. 본 연구의 결과는 e-커머스 기업 뿐만 아니라 e-커머스 산업 전반에 활용될 수 있을 것이며, 빠르게 성장하고 있는 e-커머스 생태계에 학문적 토대를 제공할 수 있을 것이다.

• International Journal of Contents
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• 제11권2호
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• pp.31-36
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• 2015

Recent years have seen a significant increase in demand for multimedia data over wireless sensor networks for monitoring applications that utilize sensor nodes to collect multimedia data, including sound and video. However, the multimedia streams generate a very large amount of data. When data transmission schemes for traditional wireless sensor networks are applied in wireless multimedia sensor networks, the network lifetime significantly decreases due to the excessive energy consumption of specific nodes. In this paper, we propose a data compression scheme that implements the Chinese remainder theorem to a wireless multimedia sensor network. The proposed scheme uses the Chinese Remainder Theorem (CRT) to compress and split multimedia data, and it then transmits the bit-pattern packets of the remainder to the base station. As a result, the amount of multimedia data that is transmitted is reduced. The superiority of our proposed scheme is demonstrated by comparing its performance to that of an existing scheme. The results of our experiment indicate that our proposed scheme significantly increased the compression ratio and reduced the compression operation in comparison to those of existing compression schemes.