• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.48 no.2
• /
• pp.43-48
• /
• 2011

Cognitive radio is accepted as an effective and promising approach for resolving the spectrum scarcity problem by allowing secondary users to borrow unused spectrum from primary users. A method of identifying busy and empty spectrum at the given time and space, which is called spectrum sensing, constitutes an essential element of the cognitive radio. In this paper, we propose a receiver-centric spectrum sensing scheme which attempts to detect the primary receiver rather than the primary transmitter. It is shown that the proposed receiver-centric sensing approach results in more efficient spectrum utilization than the conventional transmitter-centric sensing.

• Journal of the Korean Society of Costume
• /
• v.65 no.1
• /
• pp.61-75
• /
• 2015

This study is analyzes how consumers view the market leading Virtual Wedding Application in order to contribute to the development of the wedding industry in the future. The research consists of the following steps: questionnaires with detailed items were used to develop the application, the wedding application was developed, and questionnaires were used to get consumer responses. The results are as follows: 1) paid application service providing useful information is appropriate for busy consumers. 2) Regular updates regarding wedding trend are needed. 3) Augmented reality or development of HMD based virtual experience programs should be considered as virtual experience technology on smart devices evolve. 4) Wedding consumers want all kinds of instant information to be presented in harmony, so the application should allow consumers to obtain and to purchase information at the same time. 5) The application can help consumers to share the process of total wedding coordination with others around them. 6) Since people's awareness on virtual experience is relatively low, marketing strategies such as identifying the wedding application from other applications should be used as well as promoting useful functions are important.

• Journal of Information Technology Services
• /
• v.10 no.3
• /
• pp.237-250
• /
• 2011

Recently, Wireless Sensor Networks (WSN) require energy performance and guaranteed delivery delay time, contrarily with previous MAC protocols that aim to high throughput mostly. In order to satisfy the new significant requirements, many MAC protocols of WSN employ and try to enhance the duty cycle mechanism which is energy efficient technique in MAC layer. This duty cycle mechanism is oriented by toggling the transceiver conditions composed of wakeup and sleep states. The synchronous MAC protocols perform the period synchronization process. Hence, these are energy efficient in periodic monitoring environment, but are inefficient in where an event is incurred rarely and infrequently. Otherwise, the performance of asynchronous MAC protocols are contrarily with synchronous protocols. In this paper, we design two models consisting Always-busy and Always-idle ti simplify the general network congestion conditions. Through these models, moreover, we analyze two types MAC protocols in terms of energy efficiency and delay performance by analytical results. Additionally, we also evaluate two MAC protocols with two gongestion models that we designed. By the analytical and simulated results, we provide the general and efficient decision method in which protocols are more appropriate in a certain WSN environment.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.4
• /
• pp.106-115
• /
• 2019

A sharing economy has emerged through today's trust-building mechanisms, and a sharing economy is called a future economic model through a positive future market prospect. In this context, while the overseas sharing economic business is becoming a global trend, the domestic sharing economic business is busy following the global trend. The purpose of this study is to investigate the development direction of sharing economic business in Korea. First, the sharing economic cases of 50 oversea and domestic businesses were analyzed by time series analysis. Next, a cross-country analysis to analyze the business distribution and KCERN's sharing economic model through sharing economic cube model was conducted. Finally, profit model analysis through business case study and the relationship between the derived factors were investigated. As a result of the analysis, this study found comparative trends between overseas and domestic including differences in cultural and institutional environments and profit models. This study suggested directions for domestic sharing economy business.

• Journal of Digital Convergence
• /
• v.3 no.2
• /
• pp.59-71
• /
• 2005

Nowadays, it is not unusual to buy and sell goods, service and information through the internet. As a result of rapid development of Information Technology(IT), business through the internet can be done without time Limitations, place restrictions and product limitations. However, internet shopping has been restricted a lot due to the need for physical connections to the internet in order to search for information and order what we want, and this is one of the biggest problems to the busy people of the 21st century. Therefore it is very natural to use mobile phones to do shopping through wireless internet easily and conveniently whilst on the move. The purpose of this research is to find out characteristics of mobile phone users in UK, Japan and Korea and 1) main aims of the mobile phone use, 2) reasons for ease of use of mobile phones, 3) favourite types of a mobile phone, 4) psychological stability of mobile phone users, 5) problems of mobile phone use, 6) purchase goods/services via mobile phone in the future. The research method used is questionnaire survey The research results will suggest how to take actions to promote mobile commerce in the future.

• The International Journal of Costume Culture
• /
• v.12 no.1
• /
• pp.52-70
• /
• 2009

Department store has actively expanded cultural center services by providing a series of educational courses in order to increase customer visits, enhance customer satisfaction, and ultimately increase sales. In this study, cultural center members' shopping behaviors and image building of the department store were explored through focus group interviews. Results generated from a total of 7 focus group interviews with female cultural center members in their 30's through 60's are as follows. First, the consumer group who attends courses for their own purpose is 45 to 55 year-old female customers who are actively involved in consumption at the department store for their own clothing, food and restaurant. They are not often engaged in impulsive either group shopping for clothing. They are satisfied with class quality compared to low tuition whereas dissatisfied with busy schedule of a lecture room and lack of special discount benefits for members. Second, the other consumer group who attends courses for their children is consumers in their 30's. They are charged in shopping for clothing for their husbands, children, and themselves. They are suffering time poverty due to nurturing their children, therefore, they want to shop more in the department store on the day of class. However, expensive kids-care facilities are barriers to do it. Convenience, familiarity and center of culture are important images of the department store, developed through frequent visits of these customers. Eight implications for marketing strategies were generated based on study results.

• IE interfaces
• /
• v.9 no.3
• /
• pp.180-193
• /
• 1996

본 논문에서는 시뮬레이션 모델을 통해 호유형뿐만 아니라 개인통신서비스에서 필수적인 핸드오버 및 위치등록 등의 모든 트래픽 유형을 고래했을 때 개인통신교환기(PCX : Personal Commuincations Exchange)에서의 지연시간을 분석하며, 지연시간에 대한 결과와 프로세서의 이용율로부터 개인통신교환기의 호처리 및 이동성처리용량을 분석하고 그에 따른 가입자의 수용능력을 추정한다. IPC(Inter-Processor Communications) 메시지의 송수신시간 및 메시지의 처리시간등 교환기 제어계의 성능분석에 필요한 입력 파라미터 값은 기존 ISDN(Integrated Services Digital Network) 및 CMS-MX(CDMA Mobile System-Mobile Exchange) 교환기의 측정자료를 이용하였다. 시뮬레이션 분석결과 PCX 교환기의 호처리 성능은 주로 번호번역 기능을 담당하는 프로세서인 NTP(Number Translation Processor)의 용량에 의해 결정되며, 가입자 밀도가 1,500명$/km^2$인 경우 호처리용량은 약 42만 BHC(Busy Hour Call Completion)로 추정되었고, 이에 상응하는 핸드오버 및 위치등록 처리용량은 각각 시간당 약 2만 6천히 및 40만 6천회로 나타났다. 이것은 가입자당 호처리 부하가 1.6BHC일 경우, 약 15만 7천 가입자를 수용할 수 있는 용량에 해당한다.

• Journal of Environmental Health Sciences
• /
• v.35 no.3
• /
• pp.143-152
• /
• 2009

Indoor air quality at classrooms is of special concern since students are susceptible and indoor air problems can be so subtle that it does not always produce easily recognizable health effects. The main objectives of the study were to investigate the time-activity pattern of school students, to determine the sources of poor indoor air quality in schools, and to demonstrate how indoor air quality in schools causes adverse health effects such as headache, upper airway irritation, fatigue, and lethargy. Recent articles ranging from 1987-2009 related to school indoor air quality were systematically reviewed. Building-associated health effects can increase student absences from school and degrade the performance of children while in school. The reduced ventilation rate was associated with a decreased ability to concentrate along with increased adverse health symptoms. There was an association between residential proximity to busy roads and a variety of adverse respiratory health outcomes in children. Consequently, the current findings suggest the need for control strategy for school indoor air pollutants with multidisciplinary approach methods because Korea has no other natural resources except manpower especially.

• Fashion & Textile Research Journal
• /
• v.23 no.2
• /
• pp.151-158
• /
• 2021

The purpose of this study was to develop high-quality naturally dyed leisurewear with images of traditional Korean clothing that keeps a psychologically comfortable and physically pleasant environment at home and in vacation spots. The root bark of elm trees, the atopic skin, is also known to be effective for the relief of rhinitis and atopic diseases as well as stress and insomnia. However, there is insufficient color in the bark for the dyeing of fashion products, so to compensate for the lack of color, for dyeing purposes it was combined with a composite extract called Rubia akane Nakai resulting in a relatively bright red color. Except for the light fastness, all the fastnesses were rated 4 to 5, showing excellent results. Through complex dyeing using elm bark and pods extract the author produced four high-quality vests, one-piece, a gown, and jeogori-pantsuits of silk materials with Korean images that are suitable wear for relaxing comfortably at home and during breaks and which provide a comfortable and physically pleasant experience. The vest was made with the formal style of Bae-ja and Dang-eu, the dress is made of Cheok-lik, and the gown is made of Wonsam. It will be meaningful at a time when the importance of rest is increasing due to the healing clothes worn by busy modern people.

• International Journal of Computer Science & Network Security
• /
• v.22 no.12
• /
• pp.171-177
• /
• 2022

The number of people who own indoor plants is growing today, but as a result of their busy lifestyles-such as work or travel-as well as a lack of enthusiasm in caring for their plants, their plants wither. The use of an irrigation control system with a surveillance camera can assist such folks in taking care of their plants. Such a device can assist in remotely watering plants at predetermined times and checking on the health of the plants. The proprietors would be able to live comfortably without feeling bad thanks to this change. Internet access is required for this technology in order to monitor the plants and control the watering through apps. A sensor is installed in the soil to monitor soil humidity and send data to the microcontroller for irrigation, allowing the owner to schedule irrigation as they see fit and keep an eye on their plants all day. With the use of a remote irrigation control system, the plants will grow properly and be irrigated with the proper amount of water, and the owners will be so glad and delighted to watch their plants. Knowing the time and quantity of water are vital parts of the plant growth.