• 제목/요약/키워드: Hwang-to

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정보시스템 운영성과 관리시스템 구축에 관한 사례연구 (A Case Study on the Implementation of Management System for Information Systems Operational Performance)

  • 이용근;황경태
    • Journal of Information Technology Applications and Management
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    • 제24권1호
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    • pp.63-79
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    • 2017
  • This study is a subsequent research results of Lee and Hwang (2015) and presents results of the case in which an information system is developed and applied for the performance management scheme proposed by the early study. This study aims to provide the organizations that want to implement and apply an effective IS operational performance management scheme with the practical alternatives that they may consider. This study first summarize the major contents of the performance management scheme proposed by the early study. Then, the processes and detailed contents in which an information system is developed in order to operate and improve the performance management scheme. The specific contents provided by the study include the system development environments and methods, system architecture, and application structure. Finally, this study summarizes the major results of the study and suggests future research directions.

Mechanical Properties of Thermoplastic Composite Reinforced Porous Carbon

  • Hwang, Taek-Sung;Park, Jin-Won;Song, Hae-Young;Hwang, Eui-Hwan
    • Carbon letters
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    • 제1권2호
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    • pp.87-90
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    • 2000
  • Porous carbon from charcoal filled polypropylene composites were prepared and their mechanical properties were evaluated. In preparing the composites, crosslinking agent (sodium benzonate) were used in order to improve the bonding force between matrix and fillers. In this study, the effects of charcoal powder and sodium benzonate concentration on the mechanical properties and interface phenomena on the composites were evaluated. The mechanical properties of composites increased progressively with the decrease of filler loading. In the case of addition of the crosslinking agent into the composite, the mechanical properties were increased and showed maximum value at the 3 wt% concentration of sodium benzonate. According to the result of the TGA, the weight loss of composite according to crosslinking agent was not observed and initial thermal degradation temperature of composite reinforced charcoal was located at $390^{\circ}C$.

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Dual-PDA를 이용한 절삭유 에어로졸 특성분석에 관한 연구(II) - 선삭공정의 절삭유 에어로졸 예측 (A Study on the Characteristics Analysis of Cutting Fluid Aerosol Using Dual-PDA System(II) - for Cutting Fluid Aerosol Prediction in Turning Process)

  • 정의식;황덕철;우창기;황준
    • 한국분무공학회지
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    • 제10권2호
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    • pp.32-40
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    • 2005
  • This paper presents the analytical approaches to predict cutting fluid aerosol formation characteristics in machining process. The prediction model which is based on the rotary atomization theory analyzes aerosol behaviors in terms of size and concentration. Experiments were tarried out to verify the aerosol formation prediction model under various operational conditions. The experimental results which are obtained by Dual-PDA measurement show resonable agreement with prediction results of aerosol concentration. This study can be provided as a basis to estimate and control the hazardous cutting fluid aerosol in machining process in view of environmental consciousness.

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Equal Gain Block Decomposition Methods for Multiuser MIMO Networks

  • Hwang, Insoo;Kang, Inseok;Hwang, Intae;You, Cheolwoo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제15권3호
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    • pp.1156-1173
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    • 2021
  • In this paper, we propose a new joint precoder and postcoder design strategy to support multiple streams per user in multiuser multiple-input multiple-output (MIMO) systems. We propose two step precoding strategies using equal channel gain decomposition and block diagonalization at the transmitter. With the proposed precoder, the multiuser MIMO channel can be decomposed into multiple parallel channels with equal channel gain per user. After applying receive postcoder which is generated and sent by the transmitter, we can use ML based decoder per stream to achieve full receive diversity. Achievable sum rate bound and diversity performance of the proposed algorithm are presented with feedback signaling design and quantitative complexity analysis. Simulation results show that the proposed algorithm asymptotically approaches to the sum rate capacity of the MIMO broadcast channel while maintaining full diversity order.

Learning Science in Communicating Science and Technology In-the-making: A Case Study of the 'Science and Technology Mania' Award Program

  • Hwang, Sung-Won;Hwang, Book-Kee;Choi, Jung-Hoon
    • 한국과학교육학회지
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    • 제27권2호
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    • pp.126-133
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    • 2007
  • The 'Science and Technology Mania' award program is an annual nationwide award activity organized to provide teenagers with opportunities for engaging in a high-technology-based long-term project work. The task involves designing a model ship propelled by the Lorentz force (a Lorentz ship) that allows diverse approaches irreducible to one right answer, and thus adopts features of science and technology in-the-making, In this study, we attend to opportunities for learning science that the uncertain aspects of artifact-designing project provide with participants, particularly when students communicate with scientists about their design practices. We analyze oral presentation sessions of the program and articulate two findings. First, students articulate embodied knowing in the presence of scientists. Second, students enact discursive resources deployed in concrete action. We conclude that students' design practices constitute referent that communication is directed toward and therefore become resources for developing scientific discourse.

황진이 시조 「청산은 내 뜻이요」의 감정 코딩 (Emotion Coding of Sijo "Blue Mountain is My Meaning" by Hwang Jin-yi)

  • 박인과
    • 문화기술의 융합
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    • 제5권2호
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    • pp.299-303
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    • 2019
  • 이 연구는 본 연구자가 AI에 감정 코딩을 하기 위한 준비 작업의 하나이다. 이번에는 황진이의 시조 "청산은 내 뜻이요"에 대한 감정 코딩을 하는 것이다. 황진이는 이 시조에서 청산과 녹수에 감정 코딩을 하고 있다. 이러한 감정들은 Emotion Codon에서 살펴보면 UUU와 같이 감정 부호들을 코딩한다. 이러한 현상은 본 연구자가 가설을 세운 형식으로 설명될 수 있다. 즉, 이 감정 코딩은 페닐알라닌이라는 아미노산이 구성되는 촉매 역할을 한다는 것이다. 우리가 이러한 연구를 지속한다면, 인류의 미래에 보다 치유적인 문학의 기능이 활용될 것으로 사료된다.

Thermal Stability Enhanced Ge/graphene Core/shell Nanowires

  • 이재현;최순형;장야무진;김태근;김대원;김민석;황동훈;;황성우;황동목
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.376-376
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    • 2012
  • Semiconductor nanowires (NWs) are future building block for nano-scale devices. Especially, Ge NWs are fascinated material due to the high electrical conductivity with high carrier mobility. It is strong candidate material for post-CMOS technology. However, thermal stability of Ge NWs are poor than conventional semiconductor material such as Si. Especially, when it reduced size as small as nano-scale it will be melted around CMOS process temperature due to the melting point depression. Recently, Graphene have been intensively interested since it has high carrier mobility with single atomic thickness. In addition, it is chemically very stable due to the $sp^2$ hybridization. Graphene films shows good protecting layer for oxidation resistance and corrosion resistance of metal surface using its chemical properties. Recently, we successfully demonstrated CVD growth of monolayer graphene using Ge catalyst. Using our growth method, we synthesized Ge/graphene core/shell (Ge@G) NW and conducted it for highly thermal stability required devices. We confirm the existence of graphene shell and morphology of NWs using SEM, TEM and Raman spectra. SEM and TEM images clearly show very thin graphene shell. We annealed NWs in vacuum at high temperature. Our results indicated that surface melting phenomena of Ge NWs due to the high surface energy from curvature of NWs start around $550^{\circ}C$ which is $270^{\circ}C$ lower than bulk melting point. When we increases annealing temperature, tip of Ge NWs start to make sphere shape in order to reduce its surface energy. On the contrary, Ge@G NWs prevent surface melting of Ge NWs and no Ge spheres generated. Furthermore, we fabricated filed emission devices using pure Ge NWs and Ge@G NWs. Compare with pure Ge NWs, graphene protected Ge NWs show enhancement of reliability. This growth approach serves a thermal stability enhancement of semiconductor NWs.

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The Novel Biological Action of Antimicrobial Peptides via Apoptosis Induction

  • Cho, Jaeyong;Hwang, In-Sok;Choi, Hyemin;Hwang, Ji Hong;Hwang, Jae-Sam;Lee, Dong Gun
    • Journal of Microbiology and Biotechnology
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    • 제22권11호
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    • pp.1457-1466
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    • 2012
  • Antimicrobial peptides (AMPs) exert antimicrobial activity against Gram-positive and Gram-negative bacteria, fungi, and viruses by various mechanisms. AMPs commonly possess particular characteristics by harboring cationic and amphipathic structures and binding to cell membranes, resulting in the leakage of essential cell contents by forming pores or disturbing lipid organization. These membrane disruptive mechanisms of AMPs are possible to explain according to the various structure forming pores in the membrane. Some AMPs inhibit DNA and/or RNA synthesis as well as apoptosis induction by reactive oxygen species (ROS) accumulation and mitochondrial dysfunction. Specifically, mitochondria play a major role in the apoptotic pathway. During apoptosis induced by AMPs, cells undergo cytochrome c release, caspase activation, phosphatidylserine externalization, plasma or mitochondrial membrane depolarization, DNA and nuclei damage, cell shrinkage, apoptotic body formation, and membrane blebbing. Even AMPs, which have been reported to exert membrane-active mechanisms, induce apoptosis in yeast. These phenomena were also discovered in tumor cells treated with AMPs. The apoptosis mechanism of AMPs is available for various therapeutics such as antibiotics for antibiotic-resistant pathogens that resist to the membrane active mechanism, and antitumor agents with selectivity to tumor cells.

한국인의 의사소통과 자기표현에 대한 연구 -칼 융의 심리학과 퇴계의 심성론을 중심으로- (A Study on the Korean's Way of Communication and the Self-Expression - Centered to Carl G. Jung's Psychology and T·oegye Yi Hwang's theory of Human Mind and Nature -)

  • 김장이
    • 한국콘텐츠학회논문지
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    • 제14권8호
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    • pp.137-149
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    • 2014
  • 본 연구의 목적은, 한국인의 의사소통과 자기표현에서 한국인의 정서를 고찰하여, 그에 따른 감정을 이해하고 자기표현의 중요성을 밝히는데 있다. 연구 방법은 한국인의 정서는 정(情)이라고 보고, 우리가 통상적으로 사용하고 있는 정(情)의 개념과 상담 및 심리학에서 사용하고 있는 감정(感情) 개념에 대한 차이점을 규명하는 것이다. 아울러 한국인의 정(情) 문화가 의사소통에서 온전한 감정 이해와 자기표현을 어렵게 한다고 보고, 어떻게 감정이해를 하고 자기표현을 할 것인지를 고찰하는 것이다. 이를 위하여 본 연구는 소통에 있어서의 감정이해와 자기표현에 대하여 서양의 경우는, 칼 융 심리학을 통하여, 한국사상에서는 퇴계 심성론을 통하여 어떻게 보고 있는지 연구하였다. 본 연구를 통하여 밝히고자 한 것은, 의사소통과 자기표현에서 가장 중요한 것은 칼 융의 심리학에서는 큰 자기(Self)에서 나오는 감정이며, 퇴계 심성론에서는 성(性)에서 나오는 올바른 정(情)에 의한 감정이라는 것이다. 결론적으로 동 서양을 막론하고 우리의 행위의 주체는 이성이 아닌, 감정이라는 것과 마음이 통해야 행동으로 움직인다는 것을 알 수 있었다.

Simple and Clean Transfer Method for Intrinsic Property of Graphene

  • 최순형;이재현;장야무진;김병성;최윤정;황종승;황성우;황동목
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.659-659
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    • 2013
  • Recently, graphene has been intensively studied due to the fascinating physical, chemical and electrical properties. It shows high carrier mobility, high current density, and high thermal conductivity compare with conventional semiconductor materials even it has single atomic thickness. Especially, since graphene has fantastic electrical properties many researchers are believed that graphene will be replacing Si based technology. In order to realize it, we need to prepare the large and uniform graphene. Chemical vapor deposition (CVD) method is the most promising technique for synthesizing large and uniform graphene. Unfortunately, CVD method requires transfer process from metal catalyst. In transfer process, supporting polymer film (Such as poly (methyl methacrylate)) is widely used for protecting graphene. After transfer process, polymer layer is removed by organic solvents. However, it is impossible to remove it completely. These organic residues on graphene surface induce quality degradation of graphene since it disturbs movement of electrons. Thus, in order to get an intrinsic property of graphene completely remove of the organic residues is the most important. Here, we introduce modified wet graphene transfer method without PMMA. First of all, we grow the graphene from Cu foil using CVD method. And then, we deposited several metal films on graphene for transfer layer instead of PMMA. Finally, we fabricate graphene FET devices. Our approaches show low defect density and non-organic residues in comparison with PMMA coated graphene through Raman spectroscopy, SEM and AFM. In addition, clean graphene FET shows intrinsic electrical characteristic and high carrier mobility.

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