김치냉장고 내의 유동 및 열전달 특성에 관한 수치해석

윤준원 대한설비공학회 2003 설비공학 논문집 Vol.15 No.12

Kimchi refrigerator is a household electric appliance developed with the wholly domestic technology for maturing and keeping kimchi. However, the principle of keeping is not yet revealed obviously. This numerical study has been conducted to investigate the flow and heat transfer characteristics in a kimchi refrigerator. The effects of arrangement variation of a evaporation tube are examined. Also, the heat transfer characteristics through the insulation material are discussed in detail. The flow and temperature field was simulated using the commercial code of CFX-5.3. A natural convection flow is formed through about 5/6 region from the bottom within the keeping space and accordingly, the 90% region of kimchi containers satisfies the temperature requirement with 0±0.5℃. The stagnant flow exists in the upper 1/6 region of the keeping space and accordingly, the stratified high temperature distributions appear in the upper region of kimchi containers. The upward shift of the start location of a evaporation tube improves the temperature concentration toward 0℃ but the pitch variation is of no effect. The heat fluxes on the insulation surfaces show two-dimensional distributions with being higher toward the center. Through the variation of insulation thickness, 3.5% saving of insulation material is obtained under the same heat transfer rate.

대중음악 시장의 2세대 NFT 활용 연구

윤준원,이철희 한국문화융합학회 2022 문화와 융합 Vol.44 No.12

The first-generation of NFTs, which gives originality and ownership to digital data, is mainly used for artwork and has exploded the scope of the digital art market. In the popular music market, attempts have been made to utilize the technology of the first-generation NFTs, but the representative features of the 2nd generation NFT, such as 'membership', 'fandom', 'intellectual property (IP)' and 'world view', can be applied independently of the characteristic gap between temporal art and spatial art. In particular, it was confirmed that the popular music market, which has a 'membership' function and a specific group of music consumers called 'fandom', is advantageous for using the second-generation NFT. In addition, by granting intellectual property rights (IP) to NFT music, it was confirmed that buyers can create a new profit structure by creating secondary creations. Therefore, this study presented cases of use in popular music and additional methods of use, focusing on the four characteristics of second-generation NFTs as above, and predicted possible problems and suggested countermeasures.

Modeling Parkinson’s disease in the common marmoset (Callithrix jacchus): overview of models, methods, and animal care

윤준원,안재범,강병철 한국실험동물학회 2015 Laboratory Animal Research Vol.31 No.4

The common marmoset (Callithrix jacchus) is a small-bodied, popular New World monkey and is used widely in reproductive biology, neuroscience, and drug development, due to its comparative ease of handling, high reproductive efficiency, and its unique behavioral characters. In this review, we discuss the marmoset models in Parkinson’s disease (PD), which is a neurological movement disorder primarily resulting from a degeneration of dopaminergic neurons with clinical features of tremor, rigidity, postural instability, and akinesia. The most common PD models involve the administration of 1-methyl-4-phenyl- 1,2,3,6-tetrahydropyridine (MPTP) or 6-hydroxydopamine to study the pathogenesis and to evaluate novel therapies. Following the systemic or local administration of these neurotoxins, the marmosets with very severe Parkinson's symptoms are recommended to be placed in an intensive care unit with artificial feeding to increase survival rate. All procedures with MPTP should be conducted in a special room with enclosed cages under negative-pressure by trained researchers with personal protection. Behavioral tests are conducted to provide an external measure of the brain pathology. Along with several biomarkers, including α-synuclein and DJ-1, non-invasive neuroimaging techniques such as positron emission tomography and magnetic resonance imaging are used to evaluate the functional changes associated with PD. With the recent growing interest in potential and novel therapies such as stem cell and gene therapy for PD in Korea, the marmoset can be considered as a suitable non-human primate model in PD research to bridge the gap between rodent studies and clinical applications.

이동통신 사업 환경의 변화와 통신 사업자의 과제

윤준원 한국통신학회 1999 정보와 통신 Vol.16 No.7

노약자의 손 떨림 억제를 위한 웨어러블 자이로 장치의 효과에관한 실험 연구

윤준원,정슬 제어·로봇·시스템학회 2018 제어·로봇·시스템학회 논문지 Vol.24 No.3

In this paper, the performance of a gyroscopic device designed for the suppression of essential tremor (ET) in the elderly is presented. ET appears in the elderly as a movement disorder and affects daily activities such as writing, drinking, and eating. ET is characterized by a vibrating frequency that primarily falls in the 4~12 Hz bandwidth. The device is tested by creating an artificial hand which is used to generate tremors with a flywheel located on the hand that compensates for the tremors. Experimental studies are conducted to measure the suppression performance of the proposed method.

자동차 Shock Absorber의 감쇠특성에 대한 수치해석

윤준원 국립7개대학공동논문집간행위원회 2001 공업기술연구 Vol.1 No.-

Numerical analysis has been peformed to predict the characteristics of damping force of a automotive shock absorber accurately and effectively. Also, the flow resistance characteristics of damping valve components are examined to construct a accurate dynamic damper model of t suspension unit. Numerical results for the characteristics of damping force agree with test data well. It is shown that shock absorber performance can be simulated accurately without physical testing. The unique and accurate flow resistance models of valve components are obtained. They can be used in constructing a dynamic damper model and determining the size of valve components instead of a traditional sharp orifice model.

Use of Nonhuman Primates for the Development of Bioengineered Female Reproductive Organs

윤준원,김윤영,안재훈,강병철,구승엽 한국조직공학과 재생의학회 2016 조직공학과 재생의학 Vol.13 No.4

Nonhuman primates (NHPs) have been widely used in reproductive biology, neuroscience, and drug development since a number of primate species are phylogenetically close to humans. In this review, we summarize the use of NHPs for nonclinical application in the reproductive system disorders including the loss or failure of an organ or tissue. Causes of infertility include congenital aplasia and acquired disorders of the reproductive organs. In addition, anti-cancer treatments can deplete ovarian follicles, leading to premature ovarian failure, infertility and long-term health risks. Along with a limited supply of human reproductive organs, anatomic/physiologic similarities to humans support the need for NHP models (New-World monkeys such as the common marmoset and Old-World monkeys such as cynomolgus and rhesus monkeys) to promote the advances in female infertility studies. For maintaining and executing animal studies using NHP, special protocols including animal care, anesthetic protocol, surgical technique, and immunosuppressive protocol are necessary. With a growing interest in the potential therapies such as endometrial tissue engineering, and ovary/follicle cryopreservation and grafting in Korea, this review can be useful in selecting appropriate animal models and can bridge between nonclinical studies and clinical applications by providing detailed information on the use of NHPs in the field of reproductive organ disorders.

Behavior, PET and Histology in Novel Regimen of MPTP Marmoset Model of Parkinson’s Disease for Long-Term Stem Cell Therapy

윤준원,안재범,권은아,안재훈,박형욱,허훤,박진성,김현진,백선하,강병철 한국조직공학과 재생의학회 2016 조직공학과 재생의학 Vol.13 No.1

Stem cell technologies are particularly attractive in Parkinson’s disease (PD) research although they occasionally need long-term treatment for anti-parkinsonian activity. Unfortunately, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) widely used as a model for PD has several limitations, including the risk of dose-dependent mortality and the difficulty of maintenance of PD symptoms during the whole experiment period. Therefore, we tested if our novel MPTP regimen protocol (2 mg/kg for 2 consecutive days and 1 mg/kg for next 3 consecutive days) can be maintained stable parkinsonism without mortality for long-term stem cell therapy. For this, we used small-bodied common marmoset monkeys (Callithrix jacchus) among several nonhuman primates showing high anatomical, functional, and behavioral similarities to humans. Along with no mortality, the behavioral changes involved in PD symptoms were maintained for 32 weeks. Also, the loss of jumping ability of the MPTP-treated marmosets in the Tower test was not recovered by 32 weeks. Positron emission tomography (PET) analysis revealed that remarkable decreases of bindings of 18F-FP-CIT were observed at the striatum of the brains of the marmosets received MPTP during the full period of the experiment for 32 weeks. In the substantia nigra of the marmosets, the loss of tyrosine hydroxylase (TH) immunoreactivity was also observed at 32 weeks following the MPTP treatment. In conclusion, our low-dose MPTP regimen protocol was found to be stable parkinsonism without mortality as evidenced by behavior, PET, and TH immunohistochemistry. This result will be useful for evaluation of possible long-term stem cell therapy for anti-parkinsonian activity.

반능동형 충격흡수기의 연속가변 감쇠특성에 대한 CFD 해석

윤준원 국립7개대학공동논문집간행위원회 2003 공업기술연구 Vol.3 No.-

Recently, a semi-active shock absorber han been taking interest because of its lower cost and simpler structure than a active one. The CFD analysis has been conducted to investigate the continuous and variable damping characteristics of the semi-active shock absorber. Also, the flow resistance characteristics of a variable valve, namely, the spool valve has been examined to identify individual parameters(namely, exponent and discharge coefficient) needed for valve design in the dynamic modeling of a suspension unit. The flow field in the damping valve was simulated using the commercial code of CFX-5.3. the CFD results showed reasonable agreement with the experiment. The pressure distributions according to the variation of spool opening and flow rate were discussed in detail. And the continuous and variable damping performance was revealed clearly. The individual parameters of spool valve were obtained as a function of orifice area. The exponent and the discharge coefficient were fitted in with the first and the third polynomial respectively.

이동 에이전트 컴퓨팅 환경에서 공간적 복제 기반 기법을 위한 이동 에이전트 위치관리 프로토콜

윤준원,최성진,안진호,Yoon, Jun-Weon,Choi, Sung-Jin,Ahn, Jin-Ho 한국정보처리학회 2006 정보처리학회논문지 A Vol.13 No.5

다중 지역으로 구성된 이동 에이전트 컴퓨팅 환경에서 공간적 복제 기반 기법(SRBA: Spatial Replication-Based Approach)은 에이전트의 고장발생 시에도 그 에이전트의 수행이 대기 없이 계속적으로 진행될 수 있도록 하기 때문에, 대표적인 이동 에이전트 결함 포용 기법으로 사용될 수 있다. 그러나 이 기법을 실제의 이동 에이전트 기반 컴퓨팅 시스템에 적용하는데 있어서, 단계별로 복제된 이동 에이전트들에 대한 위치추적 및 관리비용을 최소화시키는 것이 필수적이다. 본 논문에서는 이러한 문제점을 해결하는 새로운 이동 에이전트 위치 관리 프로토콜인 SRLM(Location Management protocol for Spatial Replication)을 제안한다. 제안된 프로토콜은 단계군 내의 복제된 이동 에이전트들 중 대표 작업자만이 자신의 지역서버에게 위치등록하게 함으로써 기존 프로토콜에 비해 위치갱신 및 메시지 전달 비용을 매우 줄인다. 또한, 이 프로토콜은 한 단계 군에서의 대표 작업자 결함 발생시 새로운 대표 작업자의 선출로 인한 위치 관리 문제를 해결한다. In multi-regional mobile agent computing environments, spatial replication-based approach may be used as a representative mobile agent fault-tolerance technique because it allows agent execution to make progress without blocking even in case of agent failures. However, to apply this approach to real mobile agent-based computing systems, it is essential to minimize the overhead of locating and managing mobile agents replicated on each stage. This paper presents a new mobile agent location management protocol SRLM to solve this problem. The proposed protocol allows only the primary among all the replicated workers of each stage to register with its regional server and then, significantly reduces its location updating and message delivery overheads compared with the previous protocols. Also, the protocol addresses the location management problem incurred by electing the new primary among the remaining workers at a stage in case of the primary worker's failure.