• Title/Summary/Keyword: BIG4

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An Exploratory Study on the Research Framework of IT Governance and its Elements (IT Governance의 연구 틀과 구성요소에 대한 탐색적 고찰)

  • Kim, Choong Nyoung
    • Journal of Digital Convergence
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    • v.11 no.4
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    • pp.25-33
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    • 2013
  • In this paper, various definitions of IT Governance and its elements are reviewed. It seems that generally, there is no big difference in definitions and the elements of IT Governance among researchers. However, it is found that some variables which are not appropriate for its definition were used in many IT Governance research. It is also found that IT Governance research in foreign countries have been focused on structure, process, and relational mechanism. I think that the primary goal of IT Governance should be building an effective IT management system. If desirable structure and principles for IT management are established and observed strictly, we can expect desirable behavior in IT management. As a result, expected outcomes and benefits through IT investment could be possibly realized. Therefore, IT Governance research should be focused on building IT Governance systems. This paper suggests a framework for the future IT Governance research.

A Study on the Predictive Model of Propagation Path Loss in Millimeter-Wave Band (밀리미터파 대역에서 전파경로손실 예측 모델)

  • Kim, Song-Min
    • Journal of the Institute of Electronics Engineers of Korea TE
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    • v.42 no.2
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    • pp.23-28
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    • 2005
  • This study was to suggest the propagation path loss and predictive model of propagation path analysis in order to apply the frequency in the millimeter-wave band to the real time inter-vehicle communication system. This study was to suppose the case of inter-vehicle communication on the one-way two-lanes road in the big cites with a lot of traffic jams in order to analyze the effect by the reflected wave of multipath. As a simulation of suggested model, it found out that the propagation path by the reflected wave was about 0.1[m]$\sim$5.1[m] longer than the one by the direct wave during the transmission of 100[m] wave direct path. Also, as a result of comparing the propagation path loss, the loss would be about -0.8[dB]$\sim$-4.2[dB] larger in case of wall reflection and -0.8[dB]$\sim$-1[dB] vehicle reflection. From the result above, this researcher found out that the path loss of reflected wave produced by the walls was about -3.2[dB] larger than the path loss produced by the adjacent vehicles.

Failure Mechanism and Test Method for Reliability Standardization of Solder Joints (솔더조인트의 신뢰성 표준화를 위한 취성파괴 메커니즘 및 평가법 연구)

  • Kim, Kang-Dong;Huh, Seok-Hwan;Jang, Joong-Soon
    • Journal of the Microelectronics and Packaging Society
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    • v.18 no.4
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    • pp.85-90
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    • 2011
  • With regard to reliability of solder joint, the significant failures include open defects that occurs from alignment problem, Head in Pillow by PCB's warpage, the crack of solder by CTE mismatch, and the crack of IMC layer by mechanical impact. Especially as PCB down-sizing and surface finish is under progress, brittle failure of IMC layer between solder bump and PCB pad becomes a big issue. Therefore, it requires enhancing the level of difficulty in the existing assessment method and improving the measurement through the study on the mechanism of IMC formation, growth and brittle failure. Under this circumstance, this study is intended to suggest the direction of research for improving the reliability on the crack such as improvement of IMC brittle fracture.

Effect of PVP Molecular Weight on Size of Sn Nanoparticles Synthesized by Chemical Reduction (주석 나노 입자의 상온 환원 합성에서 PVP Capping Agent의 분자량에 따른 입도 변화)

  • Jang, Nam-Ie;Lee, Jong-Hyun
    • Journal of the Microelectronics and Packaging Society
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    • v.18 no.4
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    • pp.27-32
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    • 2011
  • Tin nanoparticles were synthesized at room temperature by a compulsive reduction reaction using tin(II) acetate and tin(II) chloride precursors. When an identical amount (0.015 g) of polyvinyl pyrrolidone (PVP) was added, it was concluded that the probability of abnormally big particles forming increased with an increase in PVP molecular weight, resulting in the wide distribution of Sn nanoparticles. Differential scanning calorimetry measurements were carried out using diethylene glycol solution containing synthesized tin nanoparticles. When the population of specific particles with sizes below 35 nm was adequate, the melting point depression peaks of tin nanoparticles corresponding to the specific size were observed besides an evaporation endothermic peak of DEG during the first heating. Because DEG was evaporated and tin nanoparticles in contact became molten and coarsened during the first heating, a melting peak of bulk tin was only observed at $232^{\circ}C$ during the second heating.

A Study for Development of Expressway Traffic Accident Prediction Model Using Deep Learning (딥 러닝을 이용한 고속도로 교통사고 건수 예측모형 개발에 관한 연구)

  • Rye, Jong-Deug;Park, Sangmin;Park, Sungho;Kwon, Cheolwoo;Yun, Ilsoo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.17 no.4
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    • pp.14-25
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    • 2018
  • In recent years, it has become technically easier to explain factors related with traffic accidents in the Big Data era. Therefore, it is necessary to apply the latest analysis techniques to analyze the traffic accident data and to seek for new findings. The purpose of this study is to compare the predictive performance of the negative binomial regression model and the deep learning method developed in this study to predict the frequency of traffic accidents in expressways. As a result, the MOEs of the deep learning model are somewhat superior to those of the negative binomial regression model in terms of prediction performance. However, using a deep learning model could increase the predictive reliability. However, it is easy to add other independent variables when using deep learning, and it can be expected to increase the predictive reliability even if the model structure is changed.

Catalytic Effects and Characteristics of Ni-based Catalysts Supported on TiO2-SiO2 Xerogel

  • Jeong, Jong-Woo;Park, Jong-Hui;Choi, Sung-Woo;Lee, Kyung-Hee;Lee, Chang-Seop
    • Bulletin of the Korean Chemical Society
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    • v.28 no.12
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    • pp.2288-2292
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    • 2007
  • The catalytic activities of nickel-based catalysts were estimated for oxidizing acetaldehyde of VOCs exhausted from industrial facilities. The catalysts were prepared by sol-gel methods of SiO2 and SiO2-TiO2 as a xerogel followed by impregnating Al2O3 powder with the nickel nitrate precursor. The crystalline structure and catalytic properties for the catalysts were investigated by use of BET surface area, X-ray diffraction (XRD), Xray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR) techniques. These results show that nickel oxide is transformed to NiAl2O4 spinel structure at the calcination temperature of 400 °C in response to the steps with after- and co-impregnation of Al2O3 powder in sol-gel process. The NiAl2O4 could suppress the oxidation reaction of acetaldehyde by catalysts. The NiO is better dispersed on SiO2-TiO2/Al2O3 support than SiO2/Al2O3 and SiO2-TiO2-Al2O3 supports. From the testing results of catalytic activities for oxidation of acetaldehyde, Catalysts showed a big difference in conversion efficiencies with the way of the preparation of catalysts and the loading weight of nickel. The catalyst of 8 wt.% Ni/TiO2-SiO2/Al2O3 showed the best conversion efficiency on acetaldehyde oxidation with 100% conversion efficiency at 350 °C.

Report on the 54th annual meeting of the weed science society of Japan (일본잡초학회에서 본 일본의 잡초연구 동향)

  • Hwang, Jae-Bok;Kim, Kyung-Hyun
    • Korean Journal of Agricultural Science
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    • v.42 no.4
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    • pp.335-339
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    • 2015
  • This paper reviews current status of weed science in Japanese regional agricultural systems based on the 54th Annual Meeting of the Weed Science Society of Japan. About 300 researchers from 5 countries including Korea participated in the Conference and presented 100 papers in research areas. This congress has an purpose to discuss new troubles, findings and results of weed science. Weed science faces big challenges such as increase in herbicide-resistant weeds, gene-flow from transgenic crops, and invasive weeds. Major research topics were invasive weeds and their ecology, allelopathy, weed management in paddy field, weed management in field crops, and herbicide resistance. Weed control and herbicide resistance management in paddy field were a main object of research. To prevent the increase of problematic weeds and to overcome food crisis, the importance of weed-related researches has been raised. Therefore it is expected that various weed management systems and control of herbicide resistant weeds should be studied continuously in the weed science.

Information and Communications Technology in the Field of Public Security: Crime Prevention and Response System (치안분야의 정보통신기술 활용방안 연구 - 빅데이터기반 치안수요분석과 대응체계를 중심으로 -)

  • Kim, Yeon Soo
    • Convergence Security Journal
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    • v.16 no.6_2
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    • pp.23-32
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    • 2016
  • Rapid advances in information and communications technology are new challenges and also opportunities for the police. For the purpose of identifying its implications, this study reviews utilization cases of information and communications technology in the field of public security in South Korea and other countries. As theoretical basis for utilization of information and communications technology, this study introduces intelligence-led policing, predictive policing and evidence-based policing. Also, utilization of big-data based crime analysis and crime prediction technology, as well as advancement of information and communications system and command and control technology of the police, are discussed. Based on the identified implications in this study, the following proposals are made. They are (1) procuring basic data, (2) creating an integrated database, (3) increasing utilization of policy decision-makers, (4) exchange and cooperation between related institutions, (5) training professional analyzers, (6) establishing legal basis and practical guidelines for an integrated database.

Environmental Restoration and Water Quality Management Modeling of Coastal Area by Reuse of Treated Wastewater (하수처리수 재이용에 따른 하천과 해역의 환경복원 및 수질관리 모델링)

  • Lee, Dae-In;Yoon, Yang-Ho;Park, Il-Heum;Lee, Gyu-Hyong;Cho, Hyeon-Seo
    • Journal of Environmental Science International
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    • v.16 no.4
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    • pp.505-521
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    • 2007
  • This study estimated response of water duality and pollutant behavior according to the discharge and reuse of treated wastewater by three-dimensional eco-hydrodynamic model, and suggest plan that water quality management and environmental restoration in the coastal area including urban stream of Yeosu, Korea. Dispersions of low-saline water and COD by treated wastewater loads (design facility capacity, about $110,000m^3/d$) were very limited in near of effluent site. Nutrients, however, increase compared to the other water quality factors, especially total nitrogen was very sensitive to input loads. When reuse some of treated wastewater to Yeondeung stream, nitrogen was big influence on estuarine water quality. Although current characteristics of treated wastewater such as discharge and water quality were negligible to the change of marine environment, effluent concentration of COD, TN and TP, especially 40% of TN, are reduced within the allowable pollutant loads for satisfy environmental capacity and recommended water duality criteria. Also, controls of input point/non-point sources to Yeondeung stream and base concentration of pollutants in coastal sea itself are very necessary.

Analysis of Variation in Pupil Size of Elementary Students on the Types of Generating Scientific Hypothesis (과학적 가설 생성 유형에 따른 초등학생의 동공크기 변화 분석)

  • Choi, Sungkyun;Shin, Donghoon
    • Journal of The Korean Association For Science Education
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    • v.37 no.3
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    • pp.483-492
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    • 2017
  • The purpose of this study is to analyze the variation in pupil size as shown in the scientific hypothesis generation process of students in Elementary School. The subjects for research consisted of 20 fifth-year students at Seoul B elementary school who agreed to participate in the research. The task consisted of four scientific hypothesis-generating tasks. SMI's Eye Tracker(iView $X^{TM}$ RED) was used to collect eye movement data. Experiment 3.6 and BeGaze 3.6 softwares were used to plan experiment and analyzed the task performance process and eye movement data. The findings of this study are twofold. First, there were four types that generate hypothesis about the tasks. Second, in the moment of generating hypothesis, participants' pupils have grown bigger. And while thinking of generating hypothesis or elaborating hypothesis, there were no big changes. These results show the moment of generating hypothesis is affected by emotional factors besides cognitive factors.