• Journal of the Korean Geographical Society
• /
• v.43 no.2
• /
• pp.220-234
• /
• 2008

In many security monitoring contexts, the performance or efficiency of surveillance sensors/networks based on a single sensor type may be limited by environmental conditions, like illumination change. It is well known that different modes of sensors can be complementary, compensating for failures or limitations of individual sensor types. From a location analysis and modeling perspective, a challenge is how to locate different modes of sensors to support security monitoring. A coverage-based optimization model is proposed as a way to simultaneously site k different sensor types. This model considers common coverage among different sensor types as well as overlapping coverage for individual sensor types. The developed model is used to site sensors in an urban area. Computational results show that common and overlapping coverage can be modeled simultaneously, and a rich set of solutions exists reflecting the tradeoff between common and overlapping coverage.

• Proceedings of the KIEE Conference
• /
• 2006.11a
• /
• pp.323-325
• /
• 2006

전력계통 에너지관리시스템(EMS)을 위한 공통 정보모델(CIM:Common Information Model)은 1990년대 후반에 EPRI의 CCAPI (Control Center Application Program Interface) 연구 프로젝트에서 시작하여, 현재는 IEC의 국제표준인 IEC 61970시리즈로 등록되어 있다. 특히, CIM은 IEC61970의 Part 301, 302에 정의되어 있는 공통데이터 모델을 지칭하며, IEC61970의 Part 401${\sim}$407에 정의되어 있는 CIS (Component Interface Specification)와 더불어 EMS의 API(Application Program Interface)를 정의하는 핵심 요소이다. CIM (Common Information Model)은 전격회사의 전력 시스템 운영을 포함하여 전력회사 전반에 사용되는 주요한 객체(object)들을 나타내는 추상적 모델(abstract model)이다. 또한, CIM은 전력계통 자원을 객체 클래스들(object classes)과 속성들(attributes)로 표현하는 표준 방법을 제공함으로써, 발전분야나 배전분야와 같이 전력 계통의 운용 영역이 다른 계통들과 EMS 시스템 연계, 독립적으로 개발된 전체 EMS 시스템간의 연계, 서로 다른 판매자에 의해서 독립적으로 개발된 EMS 응용 프로그램간의 통합을 용이하게 한다. 본 논문에서는 전력계통 공통 데이터 모델인 IEC 61970을 소개하고, 이에 기반을 둔 한국형 EMS 데이터베스 구축에 관해 설명한다.

• Journal of Korea Spatial Information System Society
• /
• v.2 no.1 s.3
• /
• pp.91-107
• /
• 2000

Geographic Information Systems(GISs) generally use a very large amount of spatial data. and are implemented on various software and hardware system. If it is impossible to exchange the spatial data efficiently among the different hardware, software, and operation systems, data sharing will be very difficult and duplicated storage & management of the spatial data will result in a great economic loss. To solve such problems, a national organization established a national standard for GIS and constructed spatial databases at the national level. In Korea, SDTS(Spatial Data Transfer Standard) is selected as a national standard for the common data transfer format. In this paper, we design and implement a SDTS Data Management System which can support display, insertion, update, deletion of SDTS data, extraction and creation of a specified area, error checking and reporting, setting and verification of a SDTS profile through the GUI (Graphic User Interface) environment. Hereafter, as GIS industry is continually activated and a demand for the SDTS data increases, a requirement for analysis and trust of the SDTS data will grow bigger, so the necessity of the SDTS Data Management System developed in this paper will also grow rapidly.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.8
• /
• pp.966-974
• /
• 2019

In this study, we propose a CMOS power amplifier (PA) using a bypass technique to enhance the efficiency in the low-power region. For the bypass structure, the common-gate (CG) transistor of the cascode structure of the driver stage is divided in two parallel branches. One of the CG transistors is designed to drive the power stage for high-power mode. The other CG transistor is designed to bypass the power stage for low-power mode. Owing to a turning-off of the power stage, the power consumption is decreased in low-power mode. The measured maximum output power is 20.35 dBm with a power added efficiency of 12.10%. At a measured output power of 11.52 dBm, the PAE is improved from 1.90% to 7.00% by bypassing the power stage. Based on the measurement results, we verified the functionality of the proposed bypass structure.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.22 no.1
• /
• pp.55-63
• /
• 2020

This study aimed to investigate responses of plant growth and photosynthesis to different kinds of covering materials with selective light transmit for red leaf lettuce (Lactuca sativa L.). Experimental pot design was attached UV blocking filter, red filter, blue filter, and green filter. The kinds of covering materials showed significant results for plant growth especially control, UV blocking filter, and red filter. The photosynthetic rate and anthocyanin content of red leaf lettuce were higher in control and UV blocking filter than others. The quality of red leaf lettuce was low in red, green, and blue film treatments because of too low anthocyanin content.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.8 no.3
• /
• pp.97-103
• /
• 2000

This study was performed to prove that vitrified slag can be utilized as sound absorbing materials by investigating on heavy metal elution and the properties of sound absorbing rate according to the thickness. The heavy metal elution experiment indicated that heavy metal was not eluted since it was fixed stable in the slag. Vitrified slag generally exhibited a maximum sound absorbing rate around at 600Hz-1kHz and 3kHz in the low and high frequency range, respectively. On the other hand, the absorbing rate increased beyond the range of 7kHz again. The sound absorbing rate varied a little according to the thickness of the material. However, Vitrified slag is likely to the effective as a sound absorbing wall material since it has a sound absorbing rate clover 80% in the low and high frequency region when used as a wall. The results obtained in this study showed that vitrified slag has the recyclable material properties and therefore, highly applicable to sound absorbing materials.

• Journal of Korea Port Economic Association
• /
• v.26 no.1
• /
• pp.105-130
• /
• 2010

Container terminals in Gwangyang Port are facing in domestically and internationally a lot of changes including opening of Busan New Port and China ports. Compared to new ports, container terminals in Gwangyang Port possess old equipment and facilities. Therefore, in order for Gwangyang Port to maintain its service level and remain competitive, it needs to undergo remodeling to enhance productivity economically. Remodeling activities should be implemented on a continual basis by developing and applying new technologies such as those for gate system, yard system, berth system. In order to review the alternative, we performed questionnaire survey and expert interview. From the results of analysis, we suggested remodeling technology alternatives, priority of remodeling and improvement effect by remodeling introduction stage.

• Korean Journal of Social Welfare
• /
• v.65 no.3
• /
• pp.131-153
• /
• 2013

This study examine the selection criteria for recruiting social workers, commonly agreed by the persons in charge of human resources. We visited 46 social welfare facilities and performed interviews individually with them. Thirty three items belong to 7 different areas (ability, career, suitability and agreement to the facility, characteristics, recommendation, religion) were made based on the results of interviews, and these items were sent to social welfare facilities in 16 different cities in Korea for asking questions (from Oct, 2012 to Apr, 2013). One hundred and sixty cases were collected and among them 45 cases exhibiting consistency rate less than 0.2 were finally selected. Superior scope and subordinate scope were extracted and comparisons between day care centers and living institutions were made. Results demonstrated that ability of social workers was the most important for superior scope and suitability and agreement of social workers to both day care centers and living institutions were the most important factor for recruiting workers.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.6
• /
• pp.565-571
• /
• 2000

Mixed primers based on the high sequence homology of selected regions of known connexins (Cxs) was used for PCR reaction. A full-length connexin cDNA of sweetfish (Plecoglossus altivelis) was cloned by rapid amplification of cDNA 5'and (5'RACE) and 3'RACE method. When compared to other known Cx sequences, homology of sweetfish Cx cDNA to Atlantic croaker, Mycropogonias undulatus Cx32.7, bovine, Bos taurus Cx44 and Atlantic croaker Cx32.2 were $63.8{\%},\;61.6{\%}\;and\;56.7{\%}$, respectively. This cDNA encoded 308 amino acids (35,028 dalton) and named as sweetfish Cx35. Hydropathicity analysis of predicted amino acid sequences indicated that sweetfish Cx35 have four major hydrophobic regions and four major hydrophilic regions, suggesting its topology is similar to that of known Cxs. The presence of a tfical Cx consensus sequences were identified in each of the extracellular loops (first loop and second loop).

• Journal of Service Research and Studies
• /
• v.2 no.1
• /
• pp.69-80
• /
• 2012

The process and product types of the service business are various. Though the communication and sharing for learning about experience and knowledge are very important, but up to the present, the academic and systemic research have not been activated in this field. Recently, the demand and supply in the service business are growing rapidly, the related researches by the scientific and systemic approach are required. In this study, based on the research of Ostrom's team (2010) which described the category and suggestions on the service innovation issues, in the service implementation area, some research theme candidates, research trends, and examples are introduced. In service implementation area, three theme are introduced such as Effectively branding and selling services, Enhancing the service experience through co-creation, Measuring and optimizing the value of service. Finally to the service strategy, development and implementation planning scopes, the theme of leveraging technology to advance service can be applied commonly.