• 한국정보기술학회 영문논문지
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• 제10권2호
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• pp.49-59
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• 2020

As technologies have been developing, our lives are getting easier. Today we are surrounded by the new technologies such as AI and IoT. Moreover, the word, "smart" is a very broad one because we are trying to change our daily environment into smart one by using those technologies. For example, the traditional workplaces have changed into smart offices. Since the 3rd industrial revolution, we have used the touch interface to operate the machines. In the 4th industrial revolution, however, we are trying adding the speech recognition module to the machines to operate them by giving voice commands. Today many of the things are communicated with human by voice commands. Many of them are called AI things and they do tasks which users request and do tasks more than what users request. In the 4th industrial revolution, we use smartphones all the time every day from the morning to the night. For this reason, the privacy using phone is not guaranteed sometimes. For example, the caller's voice can be heard through the phone speaker when accepting a call. So, it is needed to protect privacy on smartphone and it should work automatically according to the user context. In this aspect, this paper proposes a method to adjust the voice volume for call to protect privacy on smartphone according to the user context.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.130-133
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• 2001

VoIP(voice over internet protocol) technology is based on IP protocol. The IP protocol can be involved in two types of communication: unicasting and multicasting. Unicasting is the communication between one sender and one receiver. It is one-to-one communication. Multicasting is one-to-many communication. So that, many receivers can get same data from one sender simultaneously. and, the different protocol are proposed for VoIP; H.323, SIP and MGCP. MGCP is perfect server-client protocol, so MGCP is very attractive VoIP protocol to ISP. This paper uses MGCP and offers modified MGCP for conference call. So that, Modified MGCP is compatible to MGCP, and supports conference call using IP-multicast.

• Journal of Communications and Networks
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• 제14권4호
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• pp.461-466
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• 2012

Any future heterogeneous overlay network system must be able to support ubiquitous access across multiple wireless networks. To coordinate these diverse network environments, one challenging task is a call admission decision among different types of network. In this paper, we propose a new call admission control scheme to provide quality of service (QoS) while ensuring system efficiency. Based on the interplay between network structure and dynamics, we estimate the network's QoS level and adjust the service price adaptively with the aim of maximizing the network performance. A simulation shows that the proposed scheme can approximate an optimized solution while ensuring a well-balanced network performance in widely different network environments.

• 한국통신학회논문지
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• 제38B권7호
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• pp.535-542
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• 2013

Coordinated multi-point transmission (CoMP) is considered to be a promising technique to improve the throughput for LTE-Advanced systems. One important approach for CoMP is Joint Transmission (JT). However, the analytical model of JT has not been fully studied, as user equipments (UEs) receiving the desired signals from an adjacent base station (BS) as well as serving BS, or only serving BS were not distinguished. We derive a new analytical model to describe the call admission control in JT based systems. The performance measures of interest are the call blocking probability, and resource utilization. Furthermore, we compare the performance of JT-based systems and non-JT- based systems. The analytical results are in reasonable agreement with the simulation results.

• 산업공학
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• 제24권1호
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• pp.40-50
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• 2011

We develop a nonlinear integer programming model which minimizes the total cost with the optimal number of operators to hire and their optimal allocation to the tasks under the diverse constraints such as the weekly, daily, and hourly maximum allowable abandonment rates for the time-varying inbound call volume. We present a case study based on actual data at a call center, in order to prove the validity of applying the optimization method proposed. By the one-sample two-tailed t-test, we confirm that the expected abandonment rates resulting from the optimization method are identical with the ones from the discrete-event simulation within specified confidence intervals.

• 한국의류학회지
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• 제27권3_4호
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• pp.429-440
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• 2003

The purpose of this study is to classify the types of men's shoulders through the criteria which represent the characteristic of men's shoulders. In addition, we introduce new bodice patterns depending on our classification. We have the fo11owing conclusions based on our sample size of 200 men's shoulders: 1. The result of factor analysis indicates that six factors are extracted and they consist of 62.3% of total variance. We then choose three factors as standard items for our classification of the shape of men's shoulders. 2. We divide the shape of shoulders into three categories: bent, slopeness, and thickness. Each category is divided into three subcategories. (a) Bent: If one's shoulders are bent forward or backward, then we call them front or back-bent type. Otherwise, they are called standard-bent type. (b) Slopeness: If one's shoulders have an easy or steep slope, then we call them easy or steep slope type. Or else, they are called standard slope type. (c) Thickness: If one's shoulders are thick or thin, then we call them thick or thin type. Otherwise, we call them standard thick type. 3. According to the frequency based on our data entries of 200 men's shoulders, we introduce five new types of men's shoulders. 76.5% of examined men's shoulders belong to one of these five types: (a) 8.0% of standard slope and back-bent type: (b) 9.5% of easy slope and standard-bent type; (c) 45.5% of standard slope and standard-bent type; (d) 5.5% of steep slope and standard-bent type; (e) 8.0% of standard slope and back-bent type. 4. The suitability of new basic bodice patterns based on the types of men's shoulders are demonstrated by the high approval rate of the subjects who participate in testing.

• 보건의료산업학회지
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• 제13권4호
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• pp.215-228
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• 2019

Objectives: The purpose of this study is to figure out that Facilitation education can affect significant improvement in sales staff's understanding of precise pharmacokinetics, benefits, safety, and side effects, etc. and eventually lead to increase in call after taking courses. Methods: Data utilized in this study was collected from 413 sales staffs who completed Facilitation course for 5 months. This study used statistical methodologies, paired t-test, exploratory factor analysis, and logistic regression model in order to identify change in Call and after Facilitation courses. Results: The result shows that there are statistically significant increases in CALL quality after Facilitation courses based on the result of pared t-test. Moreover, Facilitation education is more effective in average time of one-time detail than average number of visits per day and average number of doctors per day from the result of logistic regression. Conclusions: In order for MR in pharmaceutical company to improve CALL quality, the education for precise pharmacokinetics, benefits, safety, and side effects is necessary. In addition, various professional training required for detail, including disease education, Selling Skills education, and literacy education are essential. Therefore, Facilitation education would be desirable choice in terms of pharmaceutical marketing strategy.

• 응용통계연구
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• 제24권2호
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• pp.217-225
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• 2011

본 논문에서는 스펙트럼 분석과 계절성 선형 모델을 이용하여 intra,-day 콜센터 통화량 예측에 필요한 계절성 변수를 찾아내는 방법을 제시한다. 제시한 방법을 북미 지역의 어느 은행의 5분 단위 콜센터 통화량에 실증 적용하여 기존의 통계적 방법으로는 입증할 수 없었던 월 단위 계절성 변수가 유의함을 보인다. 새로이 찾아진 연수가 intra-day 콜센터 통화량 예측능력을 향상시키는지 확인하기 위해서 새로운 변수를 포함하는 계절성 선형 모델과 이 변수를 포함하지 않은 계절성 선형 모델의 익일 통화량 예측능력을 비교 평가한다. 평가결과 새로운 변수를 포함한 모델이 우수하다는 결과를 얻었다.

• 한국정보과학회논문지:정보통신
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• 제37권6호
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• pp.494-498
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• 2010

시스템의 성능 요구 사항은 일반적으로 해당 시스템이 제공하는 서비스의 품질과 높은 연관성을 가진다. 예를 들어 이동통신 시스템에서 통화 성공률은 서비스 품질과 직결되는 사항으로 매우 높은 중요도를 가지며 체계적인 성능 시험 방법이 요구되고 있다. 본 논문에서는 구간 추정 기법을 이용하여 이동통신 시스템의 통화 성공률을 시험하는 방안을 제안한다. 또한 제안된 시험 방안을 기반으로 방송통신위원회에서 최근 시행한 3G 이동전화 서비스 품질 평가에서 사용된 판정 기준에 대해 고찰해 보고 문제점에 대해 살펴본다.

• 한국통신학회논문지
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• 제30권2A호
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• pp.61-65
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• 2005

본 논문에서는 DVB-RCS (Digital Video Broadcast-Return Channel via Satellite) 망에서 호 수락제어 (CAC)를 위한 Soft-QoS 기반의 borrowing 기법을 제안한다. 제안된 기법은 위성 망에서 사용 가능한 자원이 부족할 때 새로운 호를 받아들이기 위해 서비스 중인 호 중 일부에서 일시적이고 공평하게 대역폭을 가져온다. 각각의 호에서 가져오는 대역폭의 양은 각 사용자의 critical bandwidth ratio에 비례하며 critical bandwidth ratio는 제안된 기법에서 이용하는 QoS 파라메타 중 하나이다. 시뮬레이션 결과는 제안된 기법이 호의 blocking 확률과 대역폭 효율 측면에서 성능의 향상이 있음을 보여준다.