• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.591-593
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• 2016

Device-to-device (D2D) communications underlaid cellular infrastructure is an competitive local area services technology to promote spectrum usage for next generation cellular networks. These potential can only be tap through efficient interference coordination. Previous works only concentrated on interference from D2D pairs whiles interference from CUs to D2D pairs were neglected. This work focus on solving uplink interference problem emanating from multiple CUs sharing its resource with multiple D2D pairs. The base station (BS) acting as a supervisor selfishly institute a pricing scheme to manage the interference it experience from D2D pairs based on its Quality of service (QoS) requirement. D2D pairs following the supervisor make power allocation decisions considering the price from the BS in a non-cooperative game fashion. In order for the D2D pairs to also meet their QoS requirement, they suggest a price to the BS called discount price which reflects the interference they receive from the CUs. Finally, we analyze the proposed approach.

• 한국국방경영분석학회지
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• 제28권1호
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• pp.115-135
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• 2002

The limits of current DN(Defense networks), private and closed network, become to reality; for Example, high expense of construction and maintenance of networks, restriction of new subscribers on DN. Therefore, a network using web environment that reflect fast development of If and IS(Information Security) technology is demanded for MND. Meeting the requirement of reliable IS system and extension and improvement of DN using common network, we can reduce the expense to extend, maintain, repair DN, form the environment that makes military business cooperate better with civil company and government agency, advance implementing Defense computing and networking service for field small size units that was a exception of Defense digitalization. But it is essential to construct DN based on common network that there are security requisites; confidentiality, integrity, availability, efficiency, log, backup, restoration, that have to be realized at demanding level for IS. This thesis suggested four measurements; replacement DN with common network to resolve the requirements of building new network and improvement of performance for private DN, linkage with common network for new requirement, distribution of traffic using common network, configuration of DN using Internet and Proposed a refinement of IS management organization to treat security threat of common network flexibly, and LAN IS standard model of DN based on the web environment.

• 한국정보통신학회논문지
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• 제16권9호
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• pp.2050-2055
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• 2012

센서 네트워크가 대중화되면서 서로 다른 요구사항을 가진 다수의 응용 프로그램이 개발되고 있다. 특히, 센서 데이터의 특성상 손실되거나 시간이 지난 데이터는 의미가 없기 때문에 신뢰성과 실시간성은 매우 중요한 요구사항이다. 이를 위하여 다양한 연구들이 진행되었지만 대부분의 연구는 오직 하나의 요구사항만이 고려되었다. 이러한 문제점을 해결하기 위하여 본 논문에서는 두 개의 요구사항을 만족시키는 방안을 제안한다. 제안 메커니즘에서는 신뢰성을 위하여 개발된 MintRoute 프로토콜을 확장하여 실시간 서비스인 (m,k)-firm 스트림을 지원하도록 몇몇 기능을 확장하였다. 또한, 시뮬레이션을 통하여 성능 검증 및 제안된 프로토콜이 두 서비스에 적합함을 증명하였다.

• 한국철도학회논문집
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• 제14권6호
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• pp.507-514
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• 2011

최근 국내 협력 업체와 함께 국산 전동차를 제작하였다. 전동차에서 주 제어장치는 열차종합제어장치인 TCMS로서 시스템 성능, 편리한 유지 관리 그리고 서비스 관점의 유연성을 고려하면서 TCMS의 요구분석을 수행하였다. 이를 기반으로 새로운 내부 버스 구조와 RTOS로서 QNX를 적용하게 되었다. TCMS 기능을 서비스 장치와 제어/감시 기능으로 분리하여 열차의 성능 개선과 편리한 유지 보수 그리고 고객 요구를 만족하였다. TCMS는 하드웨어에 구현된 다양한 프로토콜을 통하여 열차에 장착된 제어 장치를 제어하고 관리한다. 시스템의 성능 검증과 안정성을 확인하기 위하여 EMC/EMI를 비롯한 다양한 시험을 KOLAS 인증 기관과 한국철도기술연구원에서 시행하였다. 현재 TCMS는 새로 개발된 열차에 장착되어서 시운전을 통하여 성능 검증을 수행하고 있다.

• Journal of Positioning, Navigation, and Timing
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• 제13권2호
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• pp.189-197
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• 2024

Galileo is a European Global Navigation Satellite System (GNSS) that has offered the Galileo Open Service since 2016. Consequently, the standardization of GNSS augmentation systems, such as Satellite Based Augmentation System (SBAS), Ground Based Augmentation System (GBAS), and Aircraft Based Augmentation System (ABAS) for Galileo signals, is ongoing. In 2023, the European Union Space Programme Agency (EUSPA) released prior probabilities of a satellite fault and a constellation fault for Galileo, which are 3×10^-5 and 2×10^-4 per hour, respectively. In particular, the prior probability of a Galileo constellation fault is significantly higher than that for the GPS constellation fault, which is defined as 1×10^-8 per hour. This raised concerns about its potential impact on GBAS integrity monitoring. According to the Global Positioning System (GPS) Standard Positioning Service Performance Standard (SPS PS), a constellation fault is classified as a wide fault. A wide fault refers to a fault that affects more than two satellites due to a common cause. Such a fault can be caused by a failure in the Earth Orientation Parameter (EOP). The EOP is used when transforming the inertial axis, on which the orbit determination is based, to Earth Centered Earth Fixed (ECEF) axis, accounting for the irregularities in the rotation of the Earth. Therefore, a faulty EOP can introduce errors when computing a satellite position with respect to the ECEF axis. In GNSS, the ephemeris parameters are estimated based on the positions of satellites and are transmitted to navigation satellites. Subsequently, these ephemeris parameters are broadcasted via the navigation message to users. Therefore, a faulty EOP results in erroneous broadcast ephemeris data. In this paper, we assess the conventional ephemeris fault detection monitor currently employed in GBAS for wide faults, as current GBAS considers only single failure cases. In addition to the existing requirements defined in the standards on the Probability of Missed Detection (PMD), we derive a new PMD requirement tailored for a wide fault. The compliance of the current ephemeris monitor to the derived requirement is evaluated through a simulation. Our findings confirm that the conventional monitor meets the requirement even for wide fault scenarios.

• 보건의료산업학회지
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• 제13권4호
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• pp.201-214
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• 2019

Objectives: The purpose of this study was to identify the needs of the senior welfare center users of the health service program, and to establish a plan to adjust the health service functions of the senior center. Methods: A survey of 2,130 users of the Gyeonggi-do Senior Welfare Center was conducted from May 28 to June 30, 2018. Results: The major results of the study are as follows. First, 66.8 percent of senior welfare center users were willing to participate in health care. The requirement for health service programs was 3.87 points out of 5 points followed by cognitive ability improvement programs, senior movement programs, and chronic disease programs in lower areas. Second, the factors affecting the needs of health care service programs of senior welfare center users had a significant impact on women; the younger the age, the better the subjective health condition; the higher the number of medical conditions, the lower the out-of-patient experience; the longer the welfare center isused, the more people are willing to participate in healthcare. Conclusions: We believe that there is a need for social service policies and management to better understand the situation of senior citizens who are demanding various services due to illness and to integrate health and welfare services.

• 한국IT서비스학회지
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• 제13권2호
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• pp.55-69
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• 2014

As Korea's global IT sourcing is sluggish and supply of qualified IT personnel does not meet the demand, IT developers currently do not worry about their job security. The sluggish global sourcing is attributed to the lack of system design and analysis skills as well as lack of communication skills of IT personnel. Most of big Korean IT service firms operate in captive market. This is also attributed to the cause of the sluggish global sourcing. Some IT managers, especially in global IT service firms, concerned about the negative long term effect of the sluggish global sourcing on competitiveness and human infra capability of Korea's IT service industry. Managers in IT service firms expect skill requirement changes in the future when global sourcing becomes active. The skills and knowledge that they wish to retain in-house is business knowledge, system analysis and design knowledge, customer relation management skills, project management skills and industry knowledge. The jobs with the above knowledge usually involve customers.

• 스마트미디어저널
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• 제6권1호
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• pp.39-46
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• 2017

The internet has become an important part of the many aspects of people's daily lives such as work, study, entertainment and in form of electronic commerce, shopping. Electronic commerce is growing rapidly in Kenya. There are many successful business-to-business, business-to-customer and customer-to-customer online shopping companies in Kenya. As a consequence, competition between vendors is intense and, therefore, mitigating the negative effects of high product uncertainty is necessary requirement as it remains a biggest hindrance for success of the online shopping. The purpose of this research is to investigate how online product description, third party product assurance, customer service and website design mitigate the negative impact of high product uncertainty. A questionnaire with 28 items is designed to collect data from online customers. Using multiple regression analysis, the relationship between dependent variable (product uncertainty) and independent variables such as product description, third party assurance, website design and customer service is tested. The result shows that all the independent variables are negatively correlated with dependent variable, which means that product description, third party assurance, website design and customer service can be used by online vendors to lessen the problem of product uncertainty in online markets.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권3호
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• pp.209-215
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• 2007

Various kind of ubiquitous healthcare services have been developed and tried in patient care and health care fields. Due to technical restrictions and not enough application practices, the service systems have been developed somewhat in ad hoc way. This paper describes the requirements for ubiquitous healthcare service systems most of which need to have and presents a ubiquitous healthcare service system architecture with which various ubiquitous healthcare services can be developed. It also introduces an application system for ubiquitous benign prostatic hyperplasia (BPH) patient care which has been developed based on the architecture.

• 산업경영시스템학회지
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• 제36권1호
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• pp.96-102
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• 2013

This paper makes a detailed comparison between two metrics designed for measuring customer's satisfaction in the retail industry. The first metric, which is called the customer service level, has not been widely used due to the intrinsic requirement on the parameter assumption(s) of the demand distribution. Unlike the customer service level metric the in stock ratio metric does not require any requirements on the demand distribution. And the in stock ratio metric is also very easy to understand the meaning. To develop the detailed planning activities for business with the in stock ratio metric on hand one should collect some information as following : 1) POS (Point of sales) data, 2) Inventory Data 3) Inventory Trend.