• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.7
• /
• pp.449-458
• /
• 2014

In the context-aware services, localization is an important technical element. Due to the easy to use and low cost, it was widely enabled with RF properties such as RSSI. However, RSSI is known to be not appropriated for indoor localization, because it tends to show big variance in time and is greatly effected with the multipath. This paper proposes a distance estimation process and its constituted methods for indoor localization, by making use of the other WLAN's RF property, CSI(Channel State Information). Firstly we define a comprehensive localization process, and suggest a calibration algorithm of environment factors in the path loss propagation model. Then, by implementing them with a commercial WLAN module, an the proposed process and methods are evaluated in terms of usefulness.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37C no.11
• /
• pp.1112-1128
• /
• 2012

In cognitive radio networks, secondary users are allowed to utilize the channels currently not occupied by primary users opportunistically. Secondary users can communicate with each other using the commonly available channels (common channels) which may change dynamically based on the activity of the primary users. Even though many studies have dealt with cognitive radio behaviors, the detailed procedures for common channel configuration have not been paid much attention. In this paper, the fast and reliable dynamic common channel setup and reconstruction method for the point-to-point communications in military cognitive radio networks is proposed. The detailed time parameters are considered for common channel setup and reconstruction, such as the packet exchange time, channel request waiting time, and rendezvous time. Through numerical analyses, the delay and throughput performance of the proposed method is derived and evaluated.

• Journal of the Korean association of regional geographers
• /
• v.16 no.6
• /
• pp.673-688
• /
• 2010

The purpose of this study is to develop an optimization model for reconstructing local administrative districts using spatial analysis and modeling. For this, literature related to reorganization of local administrative systems was critically reviewed and criteria for redistricting were extracted. An optimization model for reconstructing administrative districts was formulated based on these criteria. The model considered three criteria; homogeneity within a reconstructed district, equity among reconstructed districts, and spatial arrangement. Homogeneity for relieving spatial mismatch between administrative and living(economic) boundaries is measured by spatial interaction within a district. Equity among districts is evaluated using population, area, and financial independence. Finally, spatial arrangement is measured by compactness and contiguity. The developed optimization model was implemented using Automated Zoning Procedure(AZP) in GIS environment and applied to a problem aggregating Si-Gun administrative units into broader districts. Application results demonstrate that the model can provide optimal districts according to alternative objective functions.

• Journal of the korean Society of Automotive Engineers
• /
• v.10 no.3
• /
• pp.13-24
• /
• 1988

한국의 자동차 배출가스 규제는 1980년에 최초로 일본의 10-MODE방법을 참고로 하여 설정되어 1984년도에 1차 강화된 바 있으나, 1987년 7월 1일을 기하여 기존 규제와는 상이한 현재 미국 규제와 동일한 방법 및 규제치를 적용하게 되었다. 새로이 고시된 규제는 규제 방법 및 시험절차가 기존 방법에 비해 복잡할 뿐 아니라 규제치 자체도 상당히 낮아져서, 대기환경보전측면에서 획기적인 조치라 할 수 있다. 검사 방법 및 시험 절차가 상당히 복잡하므로 여기서는 이를 체계적으로 정리하고 요약하여 소개하고자 하며, 특히 1987년 1월 15일 고시된 '환경청 고시 제87-1호'에 의거하고자 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.191-195
• /
• 2005

Propellant remains as outage at engine shutdown contributes no useful impulse to the rocket and produces an unwanted increase in burnout weight. Minimization of outage, is therfore is a basic consideration in attaining the maximum performance capability of my bipropellant liquid rocket. This paper present the calculation procedures of outage and optimum loading propellant mass. And some control methods and measurement techniques for outage are presented.

• The Journal of Korean Association of Computer Education
• /
• v.23 no.4
• /
• pp.35-47
• /
• 2020

The purpose of this study is to provide a guideline for the programming beginners, including SW non-majors, to reduce the difficulty of establishing procedures for solving problems and to refine the work process properly in a computing environment. To accomplish this, we derive the unfolding types of typical procedures that can unfold the working procedures typically implied in daily operation in terms of recognition(input)-judgment(processing)-behavior(output). Through learning to unfold the procedure for each type, it was confirmed that the learner define the scope and rules of the problem himself and extended the procedure implied in any action. The unfolding model of the procedure developed in this study can be used as a tool for constructing a procedure operable in a computing environment to solve problems in the early stages of programming learning for non-majors or beginners.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2001.05a
• /
• pp.532-536
• /
• 2001

In responding to rapid technological change, ITU standardization activities is changing. For example, ITU-T has established new approval process for technical Recommendations, named Alternative Approval Process. This process shortens standard approval period form 9 months to 2 months. In this paper, we analyze the new approval process, AAP, step by step. And finally, we discuss .ITU reform issues such as decision making right of private industry organizations which is ongoing.

• Journal of Korea Fair Competition Federation
• /
• no.80
• /
• pp.14-19
• /
• 2002

가격상한제가 효율적으로 시행될 경우 통신사업의 생산성 향상, 신규서비스 도입촉진 등으로 보수율 규제방식에 비하여 사회후생에 긍정적 효과가 기대된다. 즉 가격상한제는 규제대상의 사업자에게 제한된 범위내에서 요금설정의 자율성을 부여함으로써, 생산성 향상의 결과를 사업자가 일부 향유할 수 있어 원가절감의 유인을 제공할 수 있다. 또한 기술발전에 따른 신규서비스 도입과 수요행태에 부응하는 다양한 요금제도의 도입을 촉진할 수도 있다. 따라서 명시적인 규제기준과 합리적인 운용절차가 설정될 경우 경쟁활성화, 요금규제의 투명성 확보 및 공정경쟁 강화 등의 효과를 기대할 수 있다.

• Journal of Welding and Joining
• /
• v.15 no.1
• /
• pp.26-35
• /
• 1997

본 연구에서는 GTAW 및 GMAW 공정에서 용접부의 열 및 물질유동해석을 수행하기 위한 지배방정식, 해석방법 및 절차를 제시하였으며, 또 실제로 해석한 결과를 에제로 살펴보았다. 그러나 용접공정은 매우 복잡한 물리적 현상을 야기하기 때문에 용접부 수치해석 모델 설정 및 해석의 수행은 용이한 일은 아니다. 그렇지만 이 분야의 연구는 용접 구조물에 대해서 사전에 용접조건 설정을 위한 실제 용접 작업 수행을 하지 않고 용접부 형상, 결함, 냉각속도, 응고 등의 예측을 위한 매우 효과적이고 경제적인 방법으로 사료되기 때문에 용접 분야에 종사하는 관련 연구자들의 관심이 한층 더 요망된다.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 1997.03a
• /
• pp.19-39
• /
• 1997

본 연구는 개방화, 탈규제화의추세와 함께 정보기술의 도입으로 인하여 큰 변화를 맞고 있는 이때 변화에 대응하기 위한 바람직한 경영조직의 설계방안을 실증적으로 제시해보고자한다. IT의 조직내 도입 및 확사과정에서 드러나는 조직간 차이를 분석함을 주안점으로 하고 있는 본 연구에서는 이 두가지 시각을 함께 수용하여1) IT의 푸쉬-풀 패러다임을 설정하여 이로부터 설문항목을 도출하고, 2) 각 항목에 대한 표준지표를 설정하고 설문을 작성·배포한 후, 3) 그 응답자료를 분석하여 우리나라 산업조직의 일반적 대응력을 분석함으로서 , 5) 이를 토대로 기업의 바람직한 조직 설계방향을 제시하는등 일련의 연구절차를 구체적으로 제시하였다.