• Title/Summary/Keyword: 이용자수

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The characteristics of optical CDMA systems using PN codes and FBGs for ultra-fast optical access networks (초고속 광 가입자망 구축을 위한 PN 부호와 FBG를 이용한 광 CDMA의 특성분석)

  • 김봉규;연영희;김병휘;박상조
    • Korean Journal of Optics and Photonics
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    • v.13 no.6
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    • pp.501-505
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    • 2002
  • We have numerically analysed the effects of the light sourer spectral power distortion in an optical CDMA system using PN codes and FBGI for ultra-fast multi-access optical networks. The interference between two CDMA channels decreases with an increase in the code length and the .simultaneous access number is equal to the code length in the region of 0 to 15% spectral power distortion. As a result, the spectral power distortion with optical spectrum is very important in designing the optical CDMA systems.

Forecasting of ADSL vs VDSL; by Using Lotka-Volterra Competition (LVC) Model

  • Cho, Byung-sun;Cho, Sang-Sup
    • Journal of Korea Technology Innovation Society
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    • v.6 no.2
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    • pp.213-227
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    • 2003
  • 초고속 인터넷 서비스는 사용자수의 증가와 더불어 고객의 다양한 욕구 즉 인터넷 방송, 주문형비디오(VOD)서비스, 원격교육, 고화질 TV 등 대용량의 멀티미디어 서비스에 대한 욕구가 폭발적으로 증가하고 있다. 이러한 욕구를 충족하기 위해서는 현재의 초고속 인터넷서비스로서는 속도에 대한 한계에 부딪치게 되어 통신사업자들은 새로운 기술 또는 여러 가지 기술적 대안들을 추구하고 있다. 2002년부터 시작하여 2003년 이후에는 멀티미디어 수요의 증가에 따라 ADSL을 대체하는 기술로 VDSL이 등장하여 매년 꾸준한 신규가입자 수요가 발생하고 있으나, 통신사업자들은 각각의 망 특성, 시장위치, 전략적 필요성 둥에 의해 상용화를 적극 검토,추진하고 있으나 각각 전개하는 방식은 조금씩 다르다. 따라서 본 연구에서는 통신사업자들의 가입자망 진화 전략에 대해 살펴 본 다음 Lot3n-Volterra Competition (LVC) 모델을 이용 ADSL 과 VDSL 두 기술간의 상호 경쟁 및 대체를 통해 어떻게 진화 되어가는지를 살펴보았다. 대표적인 통신사업자인 KT는 막강한 자금력을 바탕으로 시장 확대 및 경쟁사와의 차별화를 위해 VDSL 서비스 조기도입을 서두르고 있고, 하나로는 자금의 열세로 인한 ADSL 투자비를 회수 할때까지 VDSL 서비스를 연기하고 있는 실정이다. ADSL과 VDSL 두 기술의 관계는 Lotka-Volterra Competition (LVC) 모델을 이용한 시뮬레이션 결과를 통해 빠른 속도와 비슷한 가격대의 VDSL이 침략자(predator)로 기존 시장 지배자인 ADSL을 사냥감(prey)으로 빠른 속도로 대체해 나가는 것을 알 수 있었다.

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A Study on the Determinants of the Public Library Budget of South Korea: Focused on Macro and Micro Environments (한국 공공도서관 예산결정요인에 관한 연구 - 거시환경과 미시환경을 중심으로 -)

  • Cho, Jeong Kwon
    • Journal of the Korean Society for Library and Information Science
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    • v.53 no.3
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    • pp.5-23
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    • 2019
  • This study was conducted with a view to examining the determinants of the public library budget in the local governments of south korea. To the end, this study used the public library budget data and macro/micro environments data of 167 local governments in 2017. The analysis results shows that the determinants which have an effect on the public library budget are metropolitan area, the level of education, the population size of young adults in terms of the macro environment, and the number of users, books, and librarians in terms of the micro environment.

Support Vector Regression based on Immune Algorithm for Software Cost Estimation (소프트웨어 비용산정을 위한 면역 알고리즘 기반의 서포트 벡터 회귀)

  • Kwon, Ki-Tae;Lee, Joon-Gil
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.7
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    • pp.17-24
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    • 2009
  • Increasing use of information system has led to larger amount of developing expenses and demands on software. Until recent days, the model using regression analysis based on statistical algorithm has been used. However, Machine learning is more investigated now. This paper estimates the software cost using SVR(Support Vector Regression). a sort of machine learning technique. Also, it finds the best set of parameters applying immune algorithm. In this paper, software cost estimation is performed by SVR based on immune algorithm while changing populations, memory cells, and number of allele. Finally, this paper analyzes and compares the result with existing other machine learning methods.

A Study on the Relationship between Library budget and Library Usage (도서관 예산과 도서관 이용과의 관계에 관한 연구 - 부산지역 공공도서관을 중심으로 -)

  • Kim, Sun Ae
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.27 no.2
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    • pp.193-212
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    • 2016
  • The purpose of this paper is to explain the necessity of secure budget in public libraries with regard to promoting library usage. It is namely to attempt to find out if there really is a connection between library funding and library usage. For this purpose, the relevant data of all the 31 public libraries in Busan were collected from the 2013 National library Statistics of Korea. To determine the connection between library funding and usage, two variables were selected, 'TFI (Total Funding Indicator) = $\sqrt{personnelcosts{\times}materialcosts}$' for independent variable and 'LU (Library Usage) = (visits per year) + (loans per year)/number of inhabitants' for dependent variable. The results showed that there is a clear relationship between TFI and LU and If more cost is spent on personal resources and material resources, the total usage of the public library also increase. The findings are limited due to the fact that the observation was focusing on public libraries in one community and the period of observation was one year in 2013.

Surface Modification of Materials in KOMAC by Accelerator Technology (가속기 기술을 이용한 재료에의 표면처리기술 응용)

  • Lee, Jae-Sang
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.89-89
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    • 2017
  • 가속기 기술을 이용한 재료에의 표면처리기술은 일정에너지를 가지는 이온이 재료표면에 충돌함으로서, 스퍼터링, 이온주입, 미세구조 변화 등의 현상을 이용하여 재료표면의 특성을 변화시켜 기계적, 화학적, 광학적, 전기적 특성 등을 변화시키는 표면개질기술에 활용되어져 왔다. 이러한 이온빔 표면처리기술은 이온의 종류나 시편의 제한 없이 치밀한 원자혼합물을 형성하고, 계면형성이 없고, 또한 저온공정이 가능하므로, 정밀도가 요구되는 부품의 내마모성과 내부식성 등을 포함한 기본적인 표면특성 뿐만 아니라 전기전도도, 친소수특성, 내광성 등 표면에 관계된 특성을 개선시키는 역할을 하며, 이온빔 믹싱, 이온빔 스퍼터링, 이온빔 전처리 후 코팅 등의 복합공정을 통해 보다 개선된 표면특성을 가지는 박막제조공정에 적용될 수 있다. 본 발표에서는 지난 10년간 가속기기술을 응용한 이온빔 장치기술 개발현황을 발표하고, 이러한 장치를 활용하여 이온빔 표면처리기술 사례인 내광성/내스크래치성 향상 고분자, 정전기방지, 초친수 표면처리, 기체투과도제어, 자외선차단 필름, 고속에칭기술 등의 기술개발 현황을 발표하고자 한다. 한국원자력연구원 양성자가속기연구센터에서는 수백 keV급의 이온빔 표면처리 장치 이외에도 100MeV 선형 양성자가속기를 이용하여 2013년부터 다양한 분야의 양성자빔/이온빔 이용자들에게 이온빔 장치와 20MeV와 100MeV 이용시설에서 양성자빔/이온빔 서비스를 제공하고 있다. 2016년 기준 이용자수는 양성자가속기 392명, 이온빔장치 279명이며, 이용자 수행과제는 양성자가속기, 이온빔장치 각각 130여개 과제가 수행되었다. 이러한 이용자들의 빔이용연구를 통해 20여편의 논문투고, 10여편의 특허출원의 성과를 얻었으며, 나노분야, 생명공학분야 등의 다양한 분야에서의 빔이용기술을 통해 활발한 연구가 이루어질 것으로 예상된다.

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Impacts of Mixed-Use Development and Transportation on Housing Values (복합용도개발과 교통이 아파트가격에 미치는 영향)

  • Lee, Keum-Sook;Kim, Kyung-Min;Song, Ye-Na
    • Journal of the Economic Geographical Society of Korea
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    • v.13 no.4
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    • pp.515-528
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    • 2010
  • This study analyzes the impacts of mixed-use development and transportation on housing values in Seoul, Korea. An index measuring the land use mix is proposed using three components of land uses, residence, office, and retail, which are the essential elements for everyday urban life. This index offers a relatively easy way in measuring the level of mixed-use and proves itself useful providing sensible and reliable results in this empirical study. Also surface and underground transportation accessibilities are measured. By covering both surface and underground, a comprehensive view of Seoul's transportation accessibility is provided. Finally, housing value models are constructed with developed variables, i.e. land use mix index and accessibility measures, as well as relevant socio-economic variables. The empirical outcomes verifies that mixed-use development and transportation accessibility positively affect housing values.

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Facebook Fatigue: Narcissism, Reputation Concern, and Expectation of Others' Responses (페이스북 피로감에 대한 연구: 자기애, 평판근심, 반응기대를 중심으로)

  • Lee, Jongmin;Lee, Jihye;Sung, Yongjun
    • Journal of the HCI Society of Korea
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    • v.13 no.3
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    • pp.35-42
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    • 2018
  • Social Networking Sites (hereafter SNSs) have become a part of people's daily routines. Beginning as a hobby/communicating tool for a specific group of people, SNSs have expanded in terms of the number of users, frequency of access, and depth and range of sharing. It is recently reported that the users experience SNS fatigue from being connected at all time. However, limited research has addressed this issue. The purpose of the present study was to examine the mediating role of reputational concern and expectation of others' responses on the relationship between narcissism and Facebook fatigue. A total of 329 Facebook users completed an online survey. The results showed that individuals who rated high on narcissism experienced a high level of Facebook fatigue, and that both reputational concern and expectation of others' responses partially mediated the relationship between narcissism and fatigue. Implications of the findings and suggestions for future research are discussed.

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Predictive model plan of customer using purchasing items in internet shopping mall (인터넷 쇼핑몰에서 구매품목을 이용한 고객의 예측모델 설계)

  • Ji, Hye-Young;Cho, Wan-Hyun
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.1
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    • pp.25-37
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    • 2009
  • Recently, according to the epoch-making advancement of the Internet technique, internet using is widely expanded to the social whole not only until quantitative growth but also until qualitative growth. This research is aimed to offer plan about segmentation strategy which could be applied to business strategic establishment and the academic research, and information about solution method. In this paper, we compared similarity among purchasing products by using statistical methods such as positioning and correspondence analysis, and we tried to design predictive model for segmentation of existing customer. In conclusion, we have objective that enterprises create a benefit from the stabilized customer and customers have a benefit from enterprises by providing marketing promotion which fits the property of each person.

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A Study on Traits and Remedy of Library Anxiety among International Users in Academic Library (대학도서관 외국인 이용자의 도서관불안의 특성과 해소방안 연구)

  • Yoo, Jiyoon;Jeong, Dong Youl
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.31 no.1
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    • pp.21-42
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    • 2020
  • This study aimed to analyze library anxiety among international users in various aspects and make suggestions for alleviating library anxiety. Subjects were 'international users using the academic library' not only including international students but also including international professors and researchers to analyze library anxiety in various aspects. S university with most international users was selected for the study, and the surveys were distributed. The questionnaires completed by 369 international users were analyzed. The overall average of library anxiety among international users is 2.96, and 'knowledge of the library' appears to be the greatest source of library anxiety among international users. An analysis revealed that variables including status, nationality, library instruction, the reason for using the library, Korean proficiency, and cultural understanding contributed significantly to the library anxiety level. Based on these findings, recommendations for library service, staffing, environment, and resources were made to help alleviate library anxiety.