• Title/Summary/Keyword: 황성하(黃成河)

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Backhole as an Acoustic Damper for the Swirl Injector (스월 인젝터의 음향학적 감쇄기로서의 백홀에 대한 연구)

  • 황성하;윤영빈
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.10a
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    • pp.153-156
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    • 2003
  • Backhole, which is one of geometric parameters in swirl coaxial injectors, is found to affect the inner flow motion and the acoustic characteristics of the swirl injector. In order to analyze the effect of the backhole as a damping device such as acoustic cavities of the combustion chamber, it was regarded as a Helmholtz or Quarter-wave resonator. As a result, it is known that the swirl coaxial injector with the backhole may produce the resonant frequency coincided with the frequency of the combustion chamber.

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Multi-Point Radial Artery Pulse Wave Transducer using Pneumatic System (공압 방식에 의한 다지점 요골 맥파 검출 장치)

  • 이종진;정민석;황성하;이종현;이선규
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.243-248
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    • 2001
  • A radial artery pulse wave is well known as a good mans to diagnose human body condition in th field of Chinese medical science. Information about constitution as well as organs can be obtained by detecting the artery pulse wave. Recently, the information about the human body constitution may be utilized in accelerating the recovery process of the patient on the basis of comprehensive diagnosis. A radial artery pulse wave is considered as one of promising means in examining the human body constitution. Since the examination has been conducted by the feeling of finger, the diagnosis may occasionally have uncertainty or fatal error. In this paper, a new measuring system is suggested and developed to examine the pattern of a pulse wave correctly. The system is composed of four pressure vessels, pressure sensors and air supplying pumps. One of them is utilized for appropriately pressing the radial artery, three of them for detecting pressure change in several mmHg level. The detected data is shown and discussed.

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Effects of Backhole on Hyraulics of Liquid Rocket Swirl Coaxial Injector (액체로켓 동축형 스월인젝터에서 Backhole에 의한 수력학적 영향)

  • Hwang Seong-Ha;Seol Jaehoon;Jeong Wonho;Han Poongkyu;Yoon Youngbin
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.287-290
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    • 2002
  • 'Backhole' is an extra empty volume where is located behind the tangential entries at the rear par of the vortex chamber in the swirl coaxial injector. With the backhole, there are three major hydraulic characteristics. First, mass flow rate is increased about $15{\%}$ compared with the case without the backhole. Second, with the backhole, the center region of the injected flow has more large volume than that of without the backhole. The last, some range of the cone angle can be controlled by the backhole Experiments are conducted by using a PDPA apparatus, a mechanical patternator, stroboscopic photography and etc. With the backhole, based on cold-flow tests, the model swirl injector has some Improvement in its performance.

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Development of articulatory estimation model using deep neural network (심층신경망을 이용한 조음 예측 모형 개발)

  • You, Heejo;Yang, Hyungwon;Kang, Jaekoo;Cho, Youngsun;Hwang, Sung Hah;Hong, Yeonjung;Cho, Yejin;Kim, Seohyun;Nam, Hosung
    • Phonetics and Speech Sciences
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    • v.8 no.3
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    • pp.31-38
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    • 2016
  • Speech inversion (acoustic-to-articulatory mapping) is not a trivial problem, despite the importance, due to the highly non-linear and non-unique nature. This study aimed to investigate the performance of Deep Neural Network (DNN) compared to that of traditional Artificial Neural Network (ANN) to address the problem. The Wisconsin X-ray Microbeam Database was employed and the acoustic signal and articulatory pellet information were the input and output in the models. Results showed that the performance of ANN deteriorated as the number of hidden layers increased. In contrast, DNN showed lower and more stable RMS even up to 10 deep hidden layers, suggesting that DNN is capable of learning acoustic-articulatory inversion mapping more efficiently than ANN.

Atomic and Molecular Data Research for Plasma Applications

  • Yun, Jeong-Sik;Gwon, Deuk-Cheol;Song, Mi-Yeong;Jang, Won-Seok;Hwang, Seong-Ha;Park, Jun-Hyeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.32-32
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    • 2010
  • Since the characteristics of plasmas depend strongly on the interactions between plasma particles such as electron, ions, and neutrals, a well-established atomic and molecular database is needed to understand and produce various types of plasma. Thus, National Fusion Research Institute (NFRI) started to establish the plasma property DB for fusion and industrial plasma from last 2002. Here we describe our recent data evaluation activities regarding to production of atomic and molecular data that are needed for modeling plasma in fusion tokamaks and also low temperature industrial plasmas.

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Parental Perspectives and Child Rearing Effects on Child Abuse (부모의 자녀관과 양육태도가 자녀학대에 미치는 영향)

  • Hwang, Seong Ha
    • Korean Journal of Child Studies
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    • v.17 no.2
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    • pp.207-220
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    • 1996
  • The purpose of this study was to indentify parental perspectives and child rearing effects on child abuse with the hope that the results will be helpful in treatment and prevention of child abuse. The subjects were 181 children, 74 elementary and 107 junior high school students in Pusan. Data were analyzed by frequency, percentage, Pearson's correlation, and regression. The high correlation of parental perspectives and child rearing attitudes with child abuse suggest a causal relationship. Implications of these results indicate the need for enactment and enforcement of laws for treatment and prevention. A recommendation was made that prevention, treatment, and education concerning child abuse should be carried out under the auspices of governmental and welfare agencies.

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Customer System Tuning Methodology for Maximizing Capability and Profitability of a Web-Cased Information System (웹기반 정보시스템의 성능 및 수익성 극대화를 위한 고객시스템 튜닝 방법론)

  • Hwang, Sung-Ha;Lee, Gang-Soo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2001.10a
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    • pp.343-346
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    • 2001
  • 정보통신 인프라의 발전으로 상품에 대한 구매 의존도가 실제상점에서 웹 쇼핑몰로 변화하고 있다. 이러한 결과로 웹 쇼핑몰들이 기하급수적으로 증가하고 있다는 것을 알 수 있다. 따라서, 고객이 원하는 상품을 신속하고 안전하며 편리하게 구매할 수 있도록 서비스의 질적 향상을 위한 시스템 개발의 필요성이 대두되고 있다. 이를 위해선 고객들이 원하는 바를 충족시키고 만족시킬 수 있는 소비자(이하, 고객) 행동패턴의 획득과 폼 배치가 필요하다. 본 논문에서는 HCI 이론과 고객 행동론을 이용한 고객행동패턴 획득, 상품 레이아웃 이론을 이용한 웹 재구성, 웹서버의 워크로드 특성 및 클러스터링들을 조사, 활용 및 개량하여 고객시스템 튜닝 방법론(폼 배치 및 구조 설계방법 제시, 고객 행동패턴 획득 시스템 개발)을 제시하였다.

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The establishment of R&D management system for Gas Plant R&D Center (가스플랜트 사업단에서 연구관리스템 구축)

  • Hwang, Seong Ha;Yoo, Sun Il;Nam, Tae Hwan
    • Journal of the Korean Society of Systems Engineering
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    • v.4 no.1
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    • pp.19-29
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    • 2008
  • Traditionally gas plant R&D has had a world-wide weak position in terms of high technology. Especially System engineering did not exactly apply to gas plant construction. So, Gas Plant R&D Center is determined to make the establishment of the system engineering for the standard of gas plant. Gas Plant R&D Center has two projects. Firstly, the establishment of the R&D management system. Secondly, the system engineering which is included in the VE concept of EPC parts. But Gas Plant R&D Center exists in the particular conditions for successful development of the new process and core equipments. Now we will describe the establishment of R&D management system and particular conditions(Risk Conditions) for gas plant.

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Phytolith analysis and application in Hwangseong-dong Archaeological Site, Gyeongju (경주 황성동 유적지의 식물규소체 분석과 응용)

  • Kim, Hyo-Seon;Yoon, Soon-Ock;Hwang, Sang-Ill
    • The Korean Journal of Quaternary Research
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    • v.25 no.1
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    • pp.31-39
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    • 2011
  • Phytolith of soil in earthenware buried in the wooden chamber tombs at the archaeological site in Hwangseong-dong, Gyeongju along Hyeongsan River are analyzed. The study area has adjoined the seat of government during approximately thousand years in Shilla Dynasty and can be regarded as being closely related to the agricultural activities using the floodplains of Hyeongsan River. By the analytical results, Phragmites, Paniceae and Andropogoneae as well as Oryza sativa are found in the lower horizons, indicating the agricultural activities in the nearby areas. It is suggested for understanding the use of earthenware that the comparisons of buried soils in the site and soils in the earthenware and analysis on the macro plant fossils of soil in the earthenware are needed.

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Comparison of Bearing Capacity Equations for Rock Socketed Drilled Shalt Based on the Results of Static Pile Load Test (정재하시험을 통해 산출되는 현장타설말뚝의 지지력이론식 비교연구)

  • 천병식;황성식;이승범
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.333-340
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    • 2003
  • In Korea, drilled shaft are generally socketed into rock. Driven pile has environmental problems such as vibration and noise. Therefore, applications of the drilled shaft are increasing in Korea. In this paper, static load test data of the rock socketed drilled shaft at Gwangandaero and Suyeong 3hogyo are analyzed. The bearing capacities from field test data and theoretical formula are compared and analyzed. From this study, design approaches for drilled shafts in Korea are examined and several suggestions are proposed.

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