• 한국전자파학회논문지
• /
• 제17권5호
• /
• pp.401-407
• /
• 2006

본 논문에서는 2.4/5 GHz 이중 대역의 무선 LAN(Local Area Network) 액세스 포인트용으로 크기가 작고 가벼운 이중 공진 안테나를 제안한다. 무선 LAN용 안테나는 전방향성의 방사 패턴 특성을 보여야 한다. 먼저, 제안된 이중 공진 안테나는 전방향성의 방사 패턴을 얻기 위하여 중심에 직교 역삼각형 소자와 네 개의 공진 소자를 사방으로 위치시켰다. 또한, 중심에 직교 역삼각형 소자를 사용한 구조에서 제작이 용이하고 크기가 작은 안테나를 구성하기 위하여 중심 소자를 판형으로 변경하였다. 제안된 이중 공진 관형 안테나의 측정 결과 사용 주파수 대역에서 -12.8 dB 이하의 특성을 보였다. 이득 측정 결과 2.44 GHz에서 3.17 dBi, 5.77 GHz에서 5.38 dBi의 최대 이득을 나타내었으며 전방향성의 방사 패턴 특성을 보였다. 구현된 안테나는 무선 LAN의 액세스 포인트에 적용 가능한 성능을 나타내었다.

• 대한전자공학회논문지SP
• /
• 제44권2호
• /
• pp.19-26
• /
• 2007

시그마필터는 특성화된 근접분포구도로 시그마 값을 국부통계값들로부터 산출한다. 표준평균필터를 교정하여 잡음을 제거하는 동시에 에지를 보존하도록 설계되어 있으나 미세부분 향상에는 취약하다. 종래의 시그마 접근들도 잡음제거에 치중되어 있었을 뿐 특징구역의 향상은 소홀하였다. 본 논문은 국부통계값들과 함수 부합을 활용한 적응영상향상 알고리즘을 제안한다, 이들 값들은 영상향상의 적응 실현에 유용하여 잡음을 평활시키고 영상의 미세부분을 향상한다. 국부적응처리를 위하여 매 이동창에서 평가척도를 만족하는 파라미터가 추정되고 비중화된다. 그리고 실험 결과는 제안된 방식의 효능을 보여준다.

• 한국환경과학회지
• /
• 제6권6호
• /
• pp.613-628
• /
• 1997

Diurnal variations of air quality due to the characteristic features of local weather phenomena over Kunsan, Taegu, and Pohang are analyzed using various synoptic wand fields and the characteristics of local weather during the period of 1990 to 1992. The air pollutants analyzed are sulfur dioxide($SO2_$), nitrogen dioxide($NO_2$), and oxidants ($0_3$). The synoptic wind fields estimated at over the 850 hPa geopotential height are divided in terms of four wand directions and two wand speed categories for each season. The synoptic weather conditions are also classified Into two categories depending on the 850 hPa cloud amounts. The present study shows that the $SO_2$ concentration over Kunsan, and Taegu was maximum at the two or three hours after sunrise and second primary was three or flour hours after sunset. On the other hand, Its concentration over Kunsan was malnmum at 1900 LST or 2000 LST The $O_3$ concentration over the three cities shows Its mapdmum In the afternoon when the solar radiation is strong. The $NO_2$ concentration over Kansan shows in reverse proportion to the $O_3$ concentration over the Kunsan.

• Journal of Information Technology Applications and Management
• /
• 제15권1호
• /
• pp.183-202
• /
• 2008

The introduction of a ubiquitous environment has realized commercial ubiquitous services in various industrial fields and government area. The central and/or local governments are demanding an appropriate investment evaluation model for ubiquitous service. Thus, this study develops and suggests an evaluation model for ubiquitous service by reflecting its characteristic of promoting public good, as well as its broad ripple effect on people. The investment evaluation model for ubiquitous service suggested by this study is based on Cost Benefit Analysis Method. Especially, the 'Benefit' is analyzed in two aspects; 'Economic Benefit', which shows the benefit that ubiquitous service providers to the overall local economy, and; 'Financial Benefit', which shows the profit of individual investors participating in the introduction of ubiquitous service. The investment evaluation model for ubiquitous service suggested by this study can be used by the central and/or local government during their evaluation for investment before introducing a ubiquitous service. Also, when introducing a ubiquitous service in public field, the model can be used to support the decision making of private businesses for investment. Finally, it can be used to promote and inform the expected benefits of introducing a ubiquitous service to local residents.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 추계학술대회논문집B
• /
• pp.137-142
• /
• 2001

The effects of acoustic excitation with various frequencies for combustion air as well as fuel on the combustion emission and local NO concentration in diffusion flame were investigated experimentally. It was studied to investigate the effects of combination between four frequencies for the fuel and various frequencies for the combustion air. The better characteristic for NO emission was revealed by acoustic exciting with frequencies for the air and the fuel excited at 0Hz and 120Hz and the generation of CO was decreased at low frequency for fuel and the excited combustion air. The amount of combustion emission could be controlled by acoustic exciting of the combustion air. And when both fuel and air are excited by some frequencies, the diffusion flame was affected by frequency which excited fuel in the middle of the flame and by air-exciting frequency at both sides of the flame. The local NO in the flame was generated much less at the condition that fuel was excited by frequencies than the condition was not.

• 농업과학연구
• /
• 제49권3호
• /
• pp.667-678
• /
• 2022

A characteristic of a region's environmental resources is the competitiveness of local agricultural products. This study explores methods of making locally produced agricultural products appealing to consumers. We looked at ways to appeal to consumers by using the image of environment resource and environment-agriculture product image congruence. The relationships of two dimensions of environmental image, perceived quality and purchase intention, are examined. From the results of the study, both the image of environment resource and environment-agriculture product image congruence have a positive effect on purchasing local agricultural products through perceived quality. This study tried to ascertain which of the two dimensions of the environmental image factor is more effective in terms of consumer appeal for local agricultural products. As a result, both the image of environment resource and environment-agricultural product image congruence are found to have a positive effect on the purchase intention of consumers through perceived quality. By comparing the paths of the two dimensions it is found that the method of appealing to consumers by using the environment-agriculture product image congruence is more effective. The results of this study present an effective method of making locally produced agricultural products appealing to consumers and suggest an effective strategic direction for selling local agricultural products.

• 한국지역사회생활과학회지
• /
• 제15권4호
• /
• pp.127-136
• /
• 2004

Local fairs are often part of the economic development strategy of rural areas. This study aims to find out marketing strategies for promoting the sales of regional specialty products through local festivals in rural Korea. The data were collected in late 2003 (from a sample of interviews and surveys from 351 visitors. The data were analyzed using the SPSS computer program. The results were as follows; First, the factors that visitors were considered in purchasing were quality (49.5％), commemorative value (36.9％), and reliability (33.0％). And the top reasons cited for not buying were lack of distinction (45.1％) and high prices (26.6％). The discount rates expected in markets was 16.8％. Second, 49.8％ of visitors has spent over 10,000 won and their purchase pattern has been for themselves and their family. Third, the public organizations for certi(ication for visitors were the National Agricultural Cooperative Fedration (37.9％) and the Ministry of Agriculture and Forestry (MAF) (22.5％). In conclusion, it was important for local stakeholders to provide more locally-manufactured, seasonal and traditional food, and to plan more locally characteristic events for their fairs. Further recommendations have included having a guide showing pricing and quality standards for products bought at rural fairs, developing product ideas for inducing impulse purchases, active promotion and marketing at event sites, and setting a standard system of warranties on products under the certification of the local authorities and with the financial support of the MAF Such recommendations were aimed at increasing the sale of traditional and regional specialty products at local festivals.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2002년도 춘계학술대회 논문집
• /
• pp.134-139
• /
• 2002

Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. However, effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. Acoustic emission(AE) has been widely used in various fields because of its extreme sensitivity, dynamic detection ability and location of growing defects. In this study, we investigated failure modes of locally wall thinned pipes and AE signals by bending test. From test results, we could be divided four types of failure modes of ovalization, crack initiation after ovalization, local buckling and crack initiation after local buckling. And fracture behaviors such as elastic region, yielding range, plastic deformation range and crack progress could be evaluated by AE counts, accumulative counts and time-frequency analysis during bending test. It is expected to be basic data that can protect a risk according to local wall thinning of pipes, as a real time test of AE.

• 보건행정학회지
• /
• 제22권3호
• /
• pp.427-450
• /
• 2012

Objectives : This study examined the factors influencing variation by local areas of antibiotics prescription rate in upper respiratory infections (URI) according to the public reporting. Methods : We used the National Health Insurance Claims Data which the clinics claimed for URI (Korean Standard Classification of Disease, J00 ~ J06) in ambulatory care. The period of analysis was from the first quarter (from January to March) of 2005 to the first quarter of 2007. The number of samples was total 242 local areas that included all clinics (N = 7,942), which prescribed antibiotics for URI in ambulatory care. Results : None of the demographic and socioeconomic characteristic indicators was statistically significant. Among the provider factors, An increase in number of doctors and the average annual antibiotics prescription rate (from 2003 to 2004) for URI by local area were significantly related to an increase of antibiotics prescription rate according to the public reporting. And an increase in number of pediatric clinics, the proportion of clinics less than 5 years since has opened and the average annual fluctuation of antibiotics prescription rate (from 2003 to 2005) were significantly related to a decrease in antibiotics prescription rate by local area according to the disclosure of information. Conclusions : According to the public reporting, the antibiotics prescription rate in clinics had decreased sharply. However, the reduction of antibiotic prescription rate varied in different local areas. The factors influencing variation by local areas in antibiotics prescription rate can be used for establishing effective strategies to reduce variation by region in antibiotics prescription rate.

• 한국지역지리학회지
• /
• 제10권3호
• /
• pp.539-553
• /
• 2004

본 연구의 목적은 글로벌시대에 있어서 지방분권화가 세계적인 흐름이 되어가는 가운데 지자체에서 추구하는 국제화전략의 성과를 평가하는 척도로서, 지자체내에서의 외국인 주민과 함께 하는 지역사회 만들기 시책이 지역의 특성에 따라 어떻게 달라지는가를 분석하는데 있다. 연구방법으로는 특정지역이 가지는 지역적인 특성과 역사적 배경이 지역주민들의 사고방식과 행동패턴에 미치는 영향을 분석한다. 그 결과는 다음과 같다. 첫째, 지역에 대한 애착이 강한 토착층 주민이 많은 지역에서는 주민들의 외국인에 대한 인식이 비교적 폐쇄적이며, 신주민이 많은 지역은 비교적 개방적이었다. 둘째, 양 민족이 정치적 혹은 역사적으로, 그리고 직업구조와의 관련성이 희박할수록 타민족에 대한 의식은 무관심한 것으로 나타났다. 이러한 주민의 의식은 지자체의 외국인시책에 큰 영향을 미치지만, 동시에 지자체의 외국인시책이 지역주민의 외국인에 대한 인식을 좌우하기도 한다.