한라산 주변에 발생하는 Karman Vortex Street 재현

권지혁(Kwon Ji-hyuk·Lee),이연원(Lee Yeon-won),김영덕(Kim Young-duk),박광열(Park Kwang-yul) 한국풍공학회 2006 한국풍공학회지 Vol.10 No.1

늦가을과 초본 사이 제주도 후면에 Karman vortex street가 발생한다. 이러한 vortex가 발생하기 위해서는 기온 역전층과 5 ~ 13 m/s의 지속적인 바람이 필요하다는 것을 밝히기 위한 많은 연구들이 있었다. 이러한 vortex clouds는 발생 후 주 풍향의 방향을 이동하게 된다. Karman vortex street는 기상학에서 매우 흥미로운 주제이다. 본 연구에서는 LES 난류 모델을 이용하여 Karman vortex street에 관한 해석을 수행하고 수치해석을 통해 얻은 결과와 기상 데이터가 일치함을 보였다. From late autumn to the beginning of the spring, the phenomena of the Karman vortex street have been frequently observed in the wake of Mt. Halla in the Jeju island. Some researches revealed that the necessary conditions for development of these vortex clouds are a strong low-level inversion of temperature and a persistent wind speed of 5 to 13m/s. After the cloud is formed, the vortex clouds are shed from alternating sides of Jeju island and then move downwind with main airflow stream. The Karman vortex street in the wake of the Jeju island was one of the interesting topics in meteorology. In this study, CFD using LES turbulence model was developed to investigate the Karman vortex street and the results of CFD showed a good agreement with weather data.

가변부하를 이용한 PV모듈의 시험회로 설계

최연옥,이열선,서진연,한승조,조금배 조선대학교 동력자원연구소 1997 動力資源硏究所誌 Vol.19 No.1

A complete computerized system for the characterization and performance testing of photovoltaics(PV) modules under natural sunlight and ambient condition was designed. I-V characteristics of PV module provides on essential diagnostic means in assessing the performance and internal cell parameters of PV module depends on its basic materials, manufacturing technology and operating environmental conditions. I-V curves derived from PV modules refect to a large extent the physical properties and their expected performance. In this paper, Electrical performance measurement and evaluation methods for solar cell module by MOSFET variable Load were studied. Also, Mathematical model and theory of solar cell associated with the photovoltaic effect has been discribed.

배관내에서 자유수면 와동에 관한 연구

김상녕,이종원,오율권,장완호 慶熙大學校 1991 論文集 Vol.20 No.-

During mid­loop operation of nuclear power to prevent the residual heat removal system from failure due to air entrainment of free surface vortex in the piping system a set of simulating experiments was performed. Through these experiments, a relation between the non­dimensionalized numbers, such as submergence H/d. Froude number, Reynolds number, was found. However, the effect of the Reynolds number is not so dominant as that of the Froude number. It was also found that the boundary conditions of the free surface, that is, the perturbation of the free surface due to opening of closing pump and valves have significant effects on the free surface vortex. Futhermore a modified inlet device which reducer type with vortex breaker has strongly been recommended for the prevention of air entrainment.

한지형 잔디의 조성시기, 초종 혼합 비율이 잔디 피복에 미치는 영향

심규열(Gyu Yul Shim),김창수(Chang Soo Kim),이성호(Seong Ho Lee1),주영규(Young Kyoo Joo) 한국잡초학회·한국잔디학회 2004 Weed & Turfgrass Science Vol.18 No.4

This study was conducted to find out the effect of sodding and seeding time and rate of seed mixtures on the establishment of cool-season turfgrasses by evaluating the turf coverage rates for two years.<br/> In fall planting, the required establishment period of full coverage(100%) was 1.5 months with a rolled turf sodding(Kentucky bluegrass 100%, Kentucky bluegrass 80%+Perennial ryegrass 20%). The 100% turf establishment was achieved in 7 months with Perennial ryegrass 100%, and 7.5 months by seeding with Kentucky bluegrass 100%(KB100), Kentucky bluegrass 80%+Perennial ryegrass 20%(KB80+PR20), Kentucky bluegrass 70%+Perennial ryegrass 30%(KB70+PR30).<br/> In spring planting, the establishment periods for sod with KB100 or KB80+PR20 were taken one month. However, in the case of seeding, the establishment periods were 3 months, 3.5 months, 3.5 months and 4 months with PR100, KB80+PR20, KB70+PR30, and KB100, respectively. Comparing the turf establishment vigor between fall and spring planting, the vigor was higher in spring planting than in fall planting in both sodding and seeding.<br/> In the case of spring planting, the most proper time for turf establishment was tested on April, May, and June trials. The effect was significant in establishment vigor. The result showed highest on April planting. On May and June trials, establishment vigors were decreased gradually. As the mixture rate of PR increased, ryegrass, establishment vigor was decreased with the rates. These results indicated that perennial ryegrass has relatively less tolerant to summer heat than Kentucky bluegrass.<br/> Number of shoots in 95 days after seeding was higher in KB100 by 16,600 per ㎡ than in PR100 by 12,400 per ㎡, while the lowest number showed in KB50+PR50 by 3,300 per ㎡. Those in KB80:PR20, KB70:PR30 were 6,700 and 4,900 per ㎡, respectively. The ratios of tillers according to mixture rates between Kentucky bluegrass and perennial ryegrass were KB80:PR20=87:13, KB70:PR30=78:22, and KB50:PR50=48:52.<br/> According to results in this study, ideal seeding time might be spring (April) than in fall (September), and proper mixture rate was 80% of Kentucky bluegrass with 20% of perennial ryegrass.

수박 덩굴마름병 저항성 판별을 위한 SNP 표지인자 탐색

이혜은,홍종필,서혜영,허윤찬,안율균,김진희,김도선 忠北大學校 農業科學硏究所 2015 農業科學硏究 Vol.31 No.2

:Watermelon (Citrullus lanatus) is an important vegetable crop in the world and contains various health promoting compounds including many antioxidants such as lycopene and beta-carotene. Genetic diversity of cultivated watermelon is very narrow, which is one of major factors limiting the improvement of watermelon breeding program. Gummy stem blight (Didymella bryoniae (Auersw.)) is one of the most destructive diseases and causes crown blight, defoliation and fruit rot, resulting in severe production loss in watermelon. Single nucleotide polymorphisms (SNPs), important molecular markers for genetic studies are frequent sequence variation in the plant genome. This study was performed to develop SNP markers related to gummy stem blight resistance from three watermelon lines, one susceptible and two resistant to gummy stem blight. Of them, 22 SNP primers which were sequence information on SNPs derived from comparing a resistant and susceptible line was used for high resolution melt analysis. A total of 14 candidate SNP primers were detected melt temperature difference. These SNP primers can be useful for developing disease resistance-related markers and, therefore, beneficial to watermelon breeding program.

시나리오 역할 게임을 통한 신속 시스템 설계/검증 방법 : 패키지 응용 시스템을 대상으로 for Package Based System Implementation

예도경,이용재,강두호,최열현 한국경영과학회 1998 한국경영과학회 학술대회논문집 Vol.- No.1

Recently, many enterprises wish to preoccupy competitive positions in the market by motivating themselves towards CALS(Commerce At Light Speed), and try hard to achieve system implementation with the use of new concept-based backbone systems such as ERP(Enterprise Resource Planning) or ERP(Enterprise Resource Planning). However, unfortunately there is an inevitable discrepancy during implementation period between package vendors and customers due to lack of clear methodology and misunderstanding about system. In some cases, consensus on partially verified system design invokes customers’ continuous change demands and often it tends to result in unnecessary project delays. PDM application system implementation project of the company L has been studied here to solve these sorts of problems. The major yields of this work are achievement of a willing approval from customers and rapid system design under a time-limited and conceptually defined project scope, and finally, through fully verified system design, we were able to reach successful system implementation.

미만성 축삭 손상 환자에서의 예후 인자

음성화,임동준,김봉룡,조태형,박정율,서중근,이기찬,이훈갑 대한신경외과학회 1998 Journal of Korean neurosurgical society Vol.27 No.12

Delayed Migration of Tapered Open-Cell Design Carotid Stent: A Case Report

Lee Il Hyung,Ok Taedong,Jung Yo Han,Lee Kyung-Yul,Suh Sang Hyun 대한신경중재치료의학회 2023 Neurointervention Vol.18 No.3

We present a case of delayed migration of an open-cell design carotid stent, which is a rare complication following carotid artery stenting (CAS). A 65-year-old patient with carotid artery stenosis underwent CAS with an open-cell stent, initially achieving successful deployment. However, 4 months later, the stent migrated and resulted in restenosis. The patient underwent balloon angioplasty and received an additional stent, leading to improved blood flow. The rarity of stent migration, particularly in the absence of risk factors, highlights the need for clinicians to be vigilant and consider early imaging follow-up for patients at risk of this complication after CAS.

Comparison of the physical and chemical characteristics of fine road dust at different urban sites

Lee, Kwang Yul,Batmunkh, Tsatsral,Joo, Hung Soo,Park, Kihong Informa UK (TaylorFrancis) 2018 Journal of the Air & Waste Management Association Vol.68 No.8

Short-Term Versus Long-Term Dual Antiplatelet Therapy After Drug-Eluting Stent Implantation in Elderly Patients : A Meta-Analysis of Individual Participant Data From 6 Randomized Trials

Lee, Seung-Yul,Hong, Myeong-Ki,Palmerini, Tullio,Kim, Hyo-Soo,Valgimigli, Marco,Feres, Fausto,Colombo, Antonio,Gilard, Martine,Shin, Dong-Ho,Kim, Jung-Sun,Kim, Byeong-Keuk,Ko, Young-Guk,Choi, Donghoon Elsevier 2018 JACC. Cardiovascular interventions Vol.11 No.5

<P><B>Abstract</B></P> <P><B>Objectives</B></P> <P>This study sought to evaluate the optimal duration of dual antiplatelet therapy (DAPT) after the implantation of a drug-eluting stent (DES) in elderly patients.</P> <P><B>Background</B></P> <P>Qualified studies to evaluate the optimal duration of DAPT in elderly patients have been very limited.</P> <P><B>Methods</B></P> <P>Using 6 randomized trials that compared short-term (≤6 months) and long-term (12 months) DAPT, individual participant data meta-analysis was performed in elderly patients (≥65 years of age). The primary study outcome was the 12-month risk of a composite of myocardial infarction, definite or probable stent thrombosis, or stroke. The major secondary outcome was the 12-month risk of major bleeding.</P> <P><B>Results</B></P> <P>The primary outcome risk did not significantly differ between patients receiving short-term and long-term DAPT (hazard ratio [HR]: 1.12; 95% confidence interval [CI]: 0.88 to 1.43; p = 0.3581) in the overall group of study participants. In subgroup analysis, a significant interaction between age and DAPT duration was observed for primary outcome risk (p for interaction = 0.0384). In the subset of younger patients (<65 years of age, n = 6,152), short-term DAPT was associated with higher risk of primary outcome (HR: 1.67; 95% CI: 1.14 to 2.44; p = 0.0082). In elderly patients (n = 5,319), however, the risk of primary outcome did not significantly differ between patients receiving short-term and long-term DAPT (HR: 0.84; 95% CI: 0.60 to 1.16; p = 0.2856). Short-term DAPT was associated with a significant reduction in major bleeding compared with long-term DAPT (HR: 0.50; 95% CI: 0.30 to 0.84; p = 0.0081) in the overall group, and particularly in elderly patients (HR: 0.46; 95% CI: 0.24-0.88; p = 0.0196).</P> <P><B>Conclusions</B></P> <P>Short-term DAPT after new-generation DES implantation may be more beneficial in elderly patients than in younger patients.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>