충돌분무의 액적 거동에 미치는 비등방성 난류특성의 영향에 대한 수치해석 연구

고권현(G. H. Ko),유홍선(H. S. Ryou) 한국전산유체공학회 2003 한국전산유체공학회지 Vol.8 No.4

It is an aim of this study to perform extensive numerical study for analyzing the anisotropic turbulence effects on spatial and temporal behaviors of droplet for impinging sprays. The turbulence model of Durbin is used for comparisons with the k-E model. The turbulence-induced dispersions of droplets are consider to describe the anisotropy of turbulence effectively and spray/wall interactions are simulated using the model of Lee and Ryou. Present study investigates the overall and the internal structures of impinging diesel sprays such as spray shapes, radius and height of wall sprays, Sauter mean diameter (SMD), local droplet velocity, and local gas velocity and compared the results with experimental data by two adopted turbulence models. When the anisotropy effect of turbulence is included, better predictions for both gas and droplet tangential velocities are obtained, compared to the k-ε model. It is concluded that anisotropic effect of turbulence should be considered for simulating impinging diesel sprays.

Host People's Kindness and Migrant Workers' Cultural Adaptation: Evidence from South Korea

Jihyun Ryou(Jihyun Ryou),Sang-Yeon Kim(Sang-Yeon Kim) 한국학술연구원 2022 Korea Observer Vol.53 No.4

This study purports to determine the predictors of migrant workers' cultural adaptation in South Korea. In the main, we examined the extent to which the level of inter-/intracultural socializing, exposure to local/native media, and host culture receptivity affect the level of cultural adaptation in cognitive, affective, behavioral domains. Potential impacts of demographic factors (e.g., age, sex, ethnicity, marital status, living alone vs. with family, education level, residency in years, perceived cultural similarity) were also explored. To find answers to the research questions, a total of 634 migrant workers from 37 different nations were reached using a snowball sampling. Surveys were collected in 12 districts of Seoul, the capital of South Korea, and 21 adjacent metropolitan areas. Results indicate that intercultural interaction with host people and media exposure to local contents tend to help improve their knowledge about South Korea (e.g., language, culture). With all else equal, migrant workers treated kindly by Koreans at the workplace and in service sectors, and those living with family, compared to those who live alone, tended to enjoy a greater satisfaction with work and life in South Korea and were more willing to stay. Practical implications for Korean policymakers include encouraging competent migrant workers to move together with the family, making administrative efforts to further simplify the documentation process, and initiating public campaigns to raise host culture receptivity among Korean citizens.

Development and Application of a New Spray Impingement Model Considering Film Formation in a Diesel Engine

Ryou, Hong-Sun,Lee, Seong-Hyuk,Ko, Gwon-Hyun,Hong, Ki-Bae The Korean Society of Mechanical Engineers 2001 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.15 No.7

The present article presents an extension to the computational model for spray/wall interaction and liquid film processes that has been dealt with in the earlier studies (Lee and Ryou, 2000a). The extensions incorporate film spread due to impingement forces and dynamic motion induced by film inertia to predict the dynamic characteristics of wall films effectively. The film model includes the impingement pressure of droplets, tangential momentum transfer due to the impinging droplets on the film surface and the gas shear force at the film surface. Validation of the spray/wall interaction model and the film model was carried out for non-evaporative diesel sprays against several sources of experimental data. The computational model for spray/wall interactions was in good agreement with experimental data for both spray radius and height. The film model in the present work was better than the previous static film model, indicating that the dynamic effects of film motion should be considered for wall films. On the overall the present film model was acceptable for predication of the film radius and thickness.

Confucianism

Ryou, Soon Ha 장로회신학대학교 세계선교연구원 2000 선교와 신학 Vol.6 No.-

Immunochemical Studies on Expression of Quinoproteins in Escherichia coli

RYOU, CHONGSUK,KIM, JAE-BEOM,KWON, MOOSIK 한국미생물 · 생명공학회 2000 Journal of microbiology and biotechnology Vol.10 No.1

An immunochemical method has been developed as the most sensitive tool for studying the expression of quinoproteins containing pyrroloquinoline quinone (PQQ) in E. coli. The PQQ was conjugated to bovine serum albumin (BSA), and the conjugant was purified by using a KwikSep^™ dextran desalting column chromatography. The PQQ-BSA conjugant was immunized to rabbits, and the IgG fractions of the antisera were purified. The most sensitive antibody againt PQQ-BSA conjugant recognized some nanogram quantity of the antigen on the blot, but had little cross reactivity with BSA. Using this batch of the antibody, all the immunochemical assays of quinoproteins in E. coli were performed. Some six different PQQ-specific spots were detected by Western blot analysis of the soluble proteins in E. coli after two-dimensional gel electrophoresis. Their molecular weights on the blot were estimated to be about 100-, 90-, 72-, 58-, 52-, and 50-kDa. Their pI values fell in the range from 4.8 to 5.5. These results strongly suggest that quinoproteins are present in E. coli, and that the protein moieties were covalently bound to PQQ.

A Study on the Strength Property of Mortars with Silicon Carbide as an Additive

Ryou, Jae Suk(류재석),Kim, Hong Gi(김홍기),Kim, Jun Hyeong(김준형),Woo, Byeong Hun(우병훈),Jeon, In Kyu(전인규) 한국콘크리트학회 2018 한국콘크리트학회 학술대회 논문집 Vol.30 No.2

The Stock Market and Macroeconomic Policy in Emerging Market Economies : The Case of Korea

Ryou, Jai-Won,Kim, Tae-Joon Korean Social Science Research Council Korean Nati 2002 Korean Social Science Journal Vol.29 No.1

This paper explores the role of capital inflows through the stock into emerging market economics. For a small open economy in which equity investment is more crucial than debt investment, the relative effectiveness of monetary policy over fiscal policy does not hold. The expansionary monetary policy decreases domestic interest rates but increases the expected rate of return on equity investment. The subsequent capital inflows appreciate the domestic currency, and the net effect on output is indeterminate. Empirical evidence from the Korean economy after the currency crisis supports these findings. Meanwhile, the role of the exchange rate as a shock absorber against external shocks is shown to be important in managing macroeconomic stability.

A State Table Design for Load Balancing in distributed Computing System

Ryou, Jea-Cheol 충남대학교 자연과학연구소 1992 忠南科學硏究誌 Vol.19 No.1

분산시스템에서 부하균형이란 과부하상태인 프로세서로부터 부하가 적은 프로세서에게로 테스크들을 이동시킴으로써 평균응답시간을 줄일 수 있는 하나의 테스크 스케쥴링 방법이다. 테스크의 이동을 위해서는 각 프로세서의 부하상태에 대한 정보가 필요한데 분산시스템에서 정보를 얻는데 많은 메세지가 필요하게된다. 본 논문에서는 각 프로세서에게 송신집합을 부여하고 이 집합에 속해있는 프로세서에게만 부하정보를 보내는 방법을 사용한 결과, 부하정보를 얻는데 필요한 메세지 수가 줄어들게 되었다. 그러나 송신집합이 적절하게 선택되어야 하는데, 그렇지 않을 경우에는 일부의 프로세서간에는 서로의 부하정보를 알지못하여 부하균형이 이루어지지 않을 수가 있다. 또한 부적절한 송신집합은 특정 프로세서에게 부하균형 제어권을 주게되는 결과를 초래한다. 이에 본 논문에서는 어떤 프로세서간에도 부하균형이 이루어지며, 부하균형 제어권이 모든 프로세서에게 균등히 배분될 수 있는 송신집합을 구하여, 프로세서의 갯수가 N일때 메세지 수가 √N으로 줄어들 수 있음을 보였다. Load balancing is a task scheduling scheme for distributed computing system that transfers tasks from heavily-loaded processors to lightly-loaded or idle processors to balance workload so that average response time can be reduced. Maintaining workload information is needed in making task migration decisions. However, it may incur large message overhead. In this paper, we adapt a strategy that assigns a sending set to each processor so that load information of a processor is sent only to the processors in the sending set. Symmetrically, each processor receives load information only from a set of processors called receiving set. As a result, the size of load table can be reduced substantially. Maintaining a reduced load table requies fewer messages and less local processing time. However, sending set have to be chosen properly, otherwise load balancing may not occur between some pair of processors due to lack of load information in their load tables. Also, improper sending sets may put extra burden on some processors and leads to an uneven distribution of load balancing control. We propose an algorithm based on balanced sending sets with which load balancing can occur between any pair of processors and load balancing control is evenly distributed among participating processors. With balanced sending sets, number of messages required for each update can be reduced to the square root of the number of processors in the system. Evaluation of load balancing schemes with balanced sending sets is also presented in this paper.

Molecular Cloning and Hyperexpression of a Bt Gene, cryIAc, in Escherichia coli DH5α : Production and Usage of Anti-CryIAc Antibody

RYOU, CHONGSUK,CHUNG, TAEYOUNG,KWON, MOOSIK 한국미생물 · 생명공학회 2001 Journal of microbiology and biotechnology Vol.11 No.6

The gene coding for a Lepidoptera-specific insecticidal crystalline (or control) protein (ICP), recognized as cryLAc, from Bacillus thuringiensis subsp. kurstaki HD-73, was cloned into the vector pBluscript Ⅱ SK-, and then transformed in Escherichia coli DH5α. The clone was named EBtIAc and the chimeric phagemid, as pEBtIAc. Hyperexpression of CrylAc protoxin was observed in the extract of the culture of E. coli harboring pEBtIAc. Crystalline protoxin was purified by differential solubility. It was dissolved in alkaline pH, and exposed to trypsin to be activated. The molecular weights of the pro- and activated toxins on SDS-PAGE were estimated to be ca. 130 kDa and 60 kDa, respectively. The toxicity was tested by force-feeding larvae of gypsi moth (Lymantria dispar) with trypsinized protoxin. Using the batch of biologically active form of the toxin as an immunogen, anti-CrylAc antiserum was raised in a New Zealand white rabbit. Immunoglobulin G was fractionated from the serum by Protein-A sepharose affinity chromatography. Immunoreactivity of the antibody was examined by dot and Western blottings. It has been found that the anti-CryLAc antibody recognized the purified toxin at a level below a nanogram in terms of quantity. Using the antibody some of Bt-corns were able to be differentiated from tons of corn kernels which were imported from America as forage crops.

Effect of Silica Fume on the Pozzolanic Efficiency of Wheat Straw Ash Blended Cement Mortars

Ryou, Jae Suk(류재석),Abdul, Qudoos(압둘 쿠두스),Kim, Jun-Hyeong(김준형),Woo, Byeong Hun(우병훈) 한국콘크리트학회 2019 한국콘크리트학회 학술대회 논문집 Vol.31 No.1