PR QMF Banks와 웨이브렛 기저의 관계

권상근,서동신 金烏工科大學校 1992 論文集 Vol.13 No.-

본 논문에서는 2-channel PR FIR QMF banks와 웨이브렛 기저 사이의 관계에 대하여 설명하였다. 웨이브렛 기저는 PR FIR QMF 뱅크의 모든 성질을 가지고 있을 뿐 아니라 regularity 조건도 가지고 있다. 그러므로 웨이브렛의 조건과 기존의 PR FIR QMF뱅크를 설계하기 위하여 사용되는 2-component polyphase decomposition 방법을 이용하면 기존의 방법과 다른 방법으로 여파기를 설계하는 것이 가능하다. 이렇게 설계된 여파기들은 PR 조건을 만족할 뿐아니라 compactly supported한 직교 여파기 뱅크가 된다. In this paper, we compared the conditions exciting between PR FIR QMF banks and wavelet bases. The wavelet bases include the all the conditions of PR FIR QMF banks and regularity condition is added. The PR FIR QMF banks could be designed by using the wavelet conditions and 2-component polyphase decomposition which is employed in classical PR FIR QMF banks.

기체 주입 시스템에서 기-액 상호작용에 관한 연구

서동표,황세준,오율권 朝鮮大學校 機械技術硏究所 2001 機械技術硏究 Vol.4 No.1

Gas-injected system can be applied to various field such as metallurgical and chemical processing operations. So this study aims at presenting the relevant relationship between gas phase and liquid phase in gas-injected bath. The volume fraction, velocity, and temperature distribution of each phase were measured in order to predict the flow characteristics in gas-injected system. The gas discharged into the liquid bath loses its kinetic energy in a short distance from the nozzle exit, and then rises with a relatively uniform velocity due to buoyancy. As the gas rises upward in the liquid, the liquid entrains into the rising gas and a gas-liquid two-phase plume forms. In vertical injection systems, the gas-liquid plume is symmetric about the axis of the injection nozzle. In the region close to the orifice exit, the flow variables show steep spatial changes in both directions along the plume and across the plume. This region can be charaterized as a developing flow region.

α-Amylase Inhibitor 생산균 Streptomyces sp. AI-118의 분리 및 동정

권태종,서동진 建國大學校 附設 産業技術硏究所 1992 논문집 Vol.17 No.-

a-amylase의 효소작용을 저해하는 물질을 생산하는 균주를 토양에서 분리, 동정하였으며 저해물질 생산의 최적 조건을 검토하였다. 본균을 방선균 종정법에 따라 결과 새로운 균주로 판명되어 Streptomyces sp. AI-118이라고 명명하였다. 본 균주는 탄소원으로 corn starch 3.0%, 질소원으로 soy bean meal 1.0%, 무기염으로 NaCI 0.05%, MnSO₄·4H₂O 0.0001%, CuSO₄·5H₂O 0.0001%를 사용한 배지에서 initial pH 6.0, 30℃ 그리고 배양 72시간일 때 최대의 저해물질을 생산하였다. A microorganism, strain AI-118, capable of producing a new a-amylase inhibitor in culture broth was isolated from soil and identified as Streptomyces sp. on the morphological, cultural and physiological characteristics. The preferable medium composition has been determined to be as follows:3.0% corn starch, 1.0% soy bean meal, 0.05% NaCl, 0.05% K₂HPO₄, 0.0001%MnSO₄· 4H₂O and 0.0001% CuSO₄·5H₂O(pH6.0). The inhibitor was maximally produced after 60-80hr cultivation in a jar fermentor at 30℃.

Mid-Loop Operation 자유수면 와동현상에 관한 실험적 연구

서동표,오율권 朝鮮大學校 機械技術硏究所 2000 機械技術硏究 Vol.3 No.2

While the mid-loop of nuclear power station is in operation it is need to determine the relation of suction flow rates with in the pipe arrangement for preventing air suction phenomena caused by a free surface vortex. Therefore, in this study, correlationships between the dimensionless numbers such as submergence H/d, Froud number, Reynolds number was not as dominant as Froude number. Moreover, a modified inlet device, while is reduce type with vortex breaker has strongly been recommended for the prevention of air entrainment.

수평원관내에서 3상 혼합물의 유동특성에 관한 실험적 연구

서동표,정경진,오율권 朝鮮大學校 機械技術硏究所 2000 機械技術硏究 Vol.3 No.1

Petroleum is one of the most important energy. Recently, it is common to transport petroleum by an pipeline network than by an oiler. However, in this case, serious problem is that we have small knowledge of flow dynamics dealing with multiphase mixture. So the purpose of this study is to show the flow characteristics of the three phase flow among water, oil and air in the horizontal pipe and supply necessary data to engineers who design transport pipes. In order to investigate of a flow characteristics, the experimental results were compared each other on the basis of observations between oil and water, oil and air, and water and air.

Air-Water 모델에서 액상의 유동특성에 관한 연구

오율권,서동표,박설현 한국안전학회 2004 한국안전학회지 Vol.19 No.1

In the present study, the gas injection system based on air-water model was designed to investigate the flov< characteristics of liquid phase. A PIV system was applied to analyze the flow pattern in a ladle which gas started to rise upward from the bottom. Gas flow is one of most important factors which could feature a flow pattern in a gas injection system. As the gas injected into the liquid, the kinetic energy of bubble transfer to liquid phase and a strong circulation flow develops in the liquid phase. Such a flow in the liquid develops vortex and improve the mixing process. Due to the centrifugal force, circulation flow was well developed near both wall sides and upper region respectively. Increasing gas flow was helpful to remove dead zone but, weak flow zone still exists in spite of the increasement of gas flow rate.

FEM을 이용한 자동차 타이어용 알류미늄 합금 금형의 열변형 특성에 관한 연구

오율권,서동표,양호동,박근욱,김용범 朝鮮大學校 機械技術硏究所 2006 機械技術硏究 Vol.9 No.1

대부분의 타이어 제조를 위한 금형생산 공정은 실험적인 결과에 바탕을 두어 거의 경험치에 의존하고 있다. 이러한 방법은 금형제품을 생산하는데 있어 비효율적이고 비경제적인 측면이 많다. 따라서, 정밀도를 향상시키고 품질이 좋은 타이어를 제조하기 위해 금형의 제조공정은 재평가가 이루어져야 한다. 본 연구에서는 자동차 타이어용 알루미늄 합금 금형의열변형 및 특성을 조사하기 위해 유한요소법을 이용하여 수치해석적으로 연구를 수행하고자 하였다. 알루미늄 합금의 금형의 열변형 및 특성에 관해 조사하기 위해, 알루미늄 합금 금형 내부에서 발생되는 온도분포, 수축량, 응력 그리고 변형량을 수치해석적으로 계산하는연구를 수행하였다. 뿐만 아니라, 정밀도를 향상시키고 좋은 품질의 금형을 얻기 위해, 알루미늄 합금과 연강의 수치해석 결과를 비교하였다. 결국, 수치해석을 통해 얻은 결과들은향후 효과적이고 최상의 금형 제품을 제작하는데 도움을 줄 수 있으리라 본다. Most the mold product process is based on a experimental results and is almost dependent on experiments for tire manufacturing. This method produced the mold product is not only the ineffectiveness but also the bad economy. So, the product process of metal mold should be revaluated to produce the improved precision and good quality of tires. In this study, numerical analysis applied a finite element method (FEM) was used to predict the thermal strain characteristics of Aluminum (AI) alloy mold for automobile tire. To investigate the thermal strain and characteristics of Al alloy mold, it was performed that the temperature distribution. the contraction rates, the stress and the strain occurred on the inside of Al alloy mold was calculated by numerical works. Moreover, numerical analysis results of Al alloy mold were compared with those of mild steel mold in order to obtain the improved precision and good quality of mold. So, the numerical results of this study will be presented to help to make the effective and the best mold products.

미디어 스포츠의 스포츠 마케팅 활용을 위한 시청자 분석

김대권,서동균 한국스포츠리서치 2001 한국 스포츠 리서치 Vol.12 No.4

This research made an investigation of media sports audience characteristic and watching behavior by survey about what kind of the TV audience looked and listened with interest media sports and about with what kind of reason watched television and about whether they found satisfaction in media sports after watching. Besides was investigated whether media sports as combination of TV and sports was related to the image improvement of enterprises and an extent of sport viewing. By the foundation, this research found whether can make use of media sports as sports marketing. The subjects of this investigation were selected 295 persons (over high school, male and female) in Seoul through cluster random sampling method. The analytic method was used by questionnaire. The findings of this study were as follows: First, there were differences according to sex, age and education level in the preference degree of media sports as well as in the audience amount of media sports. And there were differences according to sex and age in the viewing satisfaction degree of media sports. Second, there were significant differences according to sex and education level in the image of enterprises. And there were significant differences according to sex and age in the degree of game inspection. Third, there was an affirmative correlation generally among a viewing act of media sports, images of sponsor enterprises, the degree of game inspection.

Ladle 내에서 기포에 따른 액상 영역의 유동학적 특성에 관한 가시적 연구

오율권,서동표,양호동 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.2

In the present study, the gas injection system based on air-water model was designed to investigate the fluid-dynamics characteristics of liquid zone into a ladle. PIV system and camera techniques were applied to analysis flow patterns at the liquid zone. Gas flow rate is one of most important factors which could feature a flow pattern in a gas injection system. At low gas flow rate, upward bubble flow induced by buoyancy force is predominant and does not make an impact on mixing due to a weak circulation flow. However, with increasing gas flow rate, the kinetic energy of bubble increases and a strong circulation flow develops in the liquid. Such a flow in the liquid develops vortex and improve the mixing process. Due to the centrifugal force, circulation flow was well developed near both wall sides and upper region respectively.

기체 주입 Ladle내에서 유동특성에 관한 연구

오율권,서동표 조선대학교 에너지.자원신기술연구소 2003 에너지·자원신기술연구소 논문지 Vol.25 No.1

In the air-water model, the characteristics of flow parameters were experimentally investigated. When gas was injected into the liquid bath, several flow patterns were observed bubble-liquid plumb, the spout flow that occurred at the free surface, liquid circulation flow by bubble's behavior, etc. In the pure liquid region, the large and small several vortices were formed and irregularly circulated. These irregular repetition and circulation play a important role of mixing in the bath. The vortices were developed in the upper and the side wall regions and the movement of flow in the low region was very small. It is known as "dead zone". The bubble rise velocity in the bottom region was relatively lower than in the upper region because the energy generated by bubbles' behavior in the near nozzle region was almost converted into kinetic energy. But bubble rise velocity increases with the increasing the axial distance since kinetic energy of bubbles is added to buoyancy force.