http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
민경우,이경석,박옥현,윤관주,김도술,박세일,정원삼,이대행,조영관,Min, Kyoung-Woo,Lee, Kyoung-Soek,Park, Ok-Hyun,Yoon, Kwan-Ju,Kim, Do-Sool,Park, Se-Il,Jeung, Won-Sam,Lee, Dae-Hang,Cho, Young-Gwan 한국환경보건학회 2015 한국환경보건학회지 Vol.41 No.3
Objectives: This study aimed to survey the characteristics of air quality and meteorological conditions in a greenway park. Methods: We measured meteorological and health related factors, including noise, particulate matter ($PM_{10}$) and selected gaseous air pollutants at three locations in a greenway park and on a general roadside as comparison. The measurements were repeated four times from April to October 2014. Results: The average air temperature in the greenway park was $20.7^{\circ}C$ which was $1-2^{\circ}C$ lower than on the general roadside. The average $PM_{10}$ concentration in the greenway park was $85.0{\mu}g/m^3$, a level 2-3 times lower than that at the roadside. The noise level at the greenway site was 4.4 dB(A)- 23.0 dB(A) lower than at the roadside. The average CO, $CO_2$, $SO_2$ and NOx concentrations in the greenway park were lower than at the roadside. The average phytoncide and anions concentrations in the greenway park were higher than at the roadside. Conclusions: The urban forest of the greenway park may have some impact on air quality and meteorological conditions.
Electrical, Thermal, and Thermoelectric Transport Properties of Se-doped Polycrystalline Re2Te5
Se Woong Lee,Okmin Park,Hyun-Sik Kim,Won-Seon Seo,Sang-il Kim 대한금속·재료학회 2022 대한금속·재료학회지 Vol.60 No.12
Re2Te5 is considered a potential thermoelectric material because of its intrinsically low thermalconductivity, due to its complex crystal structure. Herein, a series of Se-doped Re2Te5 (Re2Te5-xSex, x = 0, 0.2,1, and 2) samples were synthesized, and their electrical and thermal transport properties were investigated. Pure orthorhombic Re2Te5 phases were successfully synthesized without any impurities for all compositions,and the continuous decrease in the calculated lattice parameters confirmed the substitution of Se atoms atthe Te sites. A maximum power factor of 0.135 mW/mK2was achieved for the sample with x = 0.2 at 880 K,mainly due to the increase in carrier concentration and electrical conductivity. The lattice thermalconductivity significantly decreased for all doped samples, which was attributed to the point defect phononscattering caused by Se doping. The thermoelectric figure of merit, zT reached a maximum value of 0.20 at880 K for Re2Te4.8Se0.2 (x = 0.2) sample, which was approximately 22% higher than that of the pristine Re2Te5sample. The weighted mobility, quality factor, and expected zT were calculated to evaluate the optimizationof the power factor and zT.
박세호(Se Ho Park),이영해(Young Hae Lee),조동원(Dong Won Cho) 한국SCM학회 2012 한국SCM학회지 Vol.12 No.2
One of the most important reasons in pursuit of supply chain management is to prevent sub-optimization caused by decentralized decision making over the various entities. As supply chain coordination approach to overcome such a setting, contract mechanisms have frequently been used. However, a coordinated supply chain might fail to provide additional profit to one of the players. In result, it is necessary that a contract mechanism is designed to achieve the same profit in a centralized situation (coordination) and to improve the benefit of all the supply chain players (winwin). In this paper, we address supply chain contract based on revenue sharing and quantity discount considering price and service level. We show that the trade parameters among different entities in the supply chain contract can be chosen to achieve coordination and a win-win outcome.
Thermoelectric Properties of Cu-added Polycrystalline Bi2O2Se Oxyselenide
Si-young Bae,Se Woong Lee,Hyun-Sik Kim,Okmin Park,Hyunjin Park,Won-Seon Seo,Sang-il Kim 대한금속·재료학회 2022 대한금속·재료학회지 Vol.60 No.12
Bi2O2Se oxyselenide has been actively studied as a potential n-type thermoelectric material becauseof its intrinsically low thermal conductivity and high Seebeck coefficient (S). However, Bi2O2Se has very lowelectrical conductivity (σ), resulting in relatively poor thermoelectric performance. Herein, we investigate theeffect of Cu addition on the electrical and thermal transport of n-type polycrystalline Bi2O2Se. A series ofCuxBi2O2Se (x = 0, 0.0025, 0.005, and 0.0075) polycrystalline samples were synthesized by a conventional solid state reaction. Tetragonal Bi2O2Se was successfully synthesized, and its lattice parameters graduallydecreased with the addition of Cu. Further, σ decreased and the magnitude of S increased with increasingCu content, according to the trade-off relationship between these parameters. Consequently, a maximumpower factor of 0.106 mW m-1 K-2 was achieved for the sample with x = 0.0025 at 300 K, owing to the increasein the magnitude of S. The Hall carrier concentration decreased exponentially with the addition of Cu, whichis mainly attributed to the possible enlargement of the band gap of the Cu-added samples. The lattice thermalconductivity decreased with increasing x, which was attributed to point-defect phonon scattering via Cuaddition. Therefore, a maximum zT of 0.222 was obtained at 790 K for the Cu0.0025Bi2O2Se (x = 0.0025) sample,which was approximately 8% higher than that of the pristine Bi2O2Se sample.
Park, Chailinn,Lee, Won-Kyung,Kim, Se-Joo,Ju, Se-Jong The Korean Society of Systematic Zoology 2020 Animal Systematics, Evolution and Diversity Vol.36 No.2
Isaacsicalanus paucisetus Fleminger, 1983, a monotypic species of the family Spinocalanidae Vervoort, 1951, was first reported from a hydrothermal vent field in the East Pacific Rise off the mouth of the Gulf of California. The mitochondrial cytochrome oxidase I(mtCOI) DNA barcodes are considered a useful tool to assist traditional taxonomy and species discrimination in calanoid copepods. However, the mtCOI DNA barcodes of I. paucisetus have not been reported due to the species rarity and the difficulty of sampling. In this study, we firstly determined the mtCOI DNA barcodes of the I. paucisetus newly collected from a hydrothermal vent in the North Fiji Basin of the southwestern Pacific. All mtCOI DNA barcodes of I. paucisetus were identical and intraspecies variations of spinocalanid species were 0.0-3.0%. Interspecies and intergeneric variations were 13.4-25.2% and 16.7-24.1%, respectively. The DNA barcodes of I. paucisetus obtained in the present study would be helpful for understanding taxonomic relationships of widespread spinocalanid species.
Calculation of Pressure Profiles in a Molecular Flow Regime using LTSpice IV
Won-Shik Choi,Kun-Uk Kang,Se-Hyun Kim,Chongdo Park 한국진공학회(ASCT) 2016 Applied Science and Convergence Technology Vol.25 No.4
This article describes an electrical network analysis (ENA) method to calculate the pressure distribution of a vacuum system in a molecular flow regime. The vacuum system was modeled using electrical components. For an accurate analysis, a complexly combined pipe model, excluding entrance conductance, was employed and the pressure distribution was simulated using ENA. A vacuum system comprising three vacuum pumps was used for simplicity. In addition, the ENA results were compared with results from finite element analysis (FEA) and experimental measurements. The pressure distribution profiles estimated from ENA, performed using the LTSpice IV software, were in agreement with FEA and experimental results.
Park, Young-Min,Ryu, Han-Seong,Lee, Hyun-Won,Jung, Myung-Gil,Lee, Se-Hyun The Korean Institute of Power Electronics 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.3
This paper proposes a practical design for a Cascaded H-Bridge Multilevel (CHBM) inverter based on Power Electronics Building Blocks (PEBB) and high performance control to improve current control and increase fault tolerance. It is shown that the expansion and modularization characteristics of the CHBM inverter are improved since the individual inverter modules operate more independently, when using the PEBB concept. It is also shown that the performance of current control can be improved with voltage delay compensation and the fault tolerance can be increased by using unbalance three-phase control. The proposed design and control methods are described in detail and the validity of the proposed system is verified experimentally in various industrial fields.
Effects of partially earth-anchored cable system on dynamic wind response of cable-stayed bridges
Won, Jeong-Hun,Yoon, Ji-Hyun,Park, Se-Jun,Kim, Sang-Hyo Techno-Press 2008 Wind and Structures, An International Journal (WAS Vol.11 No.6
In this study, a partially earth-anchored cable system is studied in order to reduce the dynamic wind response of cable-stayed bridges. The employment of earth-anchored cables changes the dynamic characteristics of cable-stayed bridges under wind loads. In order to estimate the changes in the member forces, the spectral analysis for wind buffeting loads are performed and the peak responses are evaluated using 3-D finite element models of the three-span cable-stayed bridges with the partially earth-anchored cable system and with the self-anchored cable system, respectively. Comparing the results for the two different models, it is found that the earth-anchored cables affect longitudinal and vertical modes of the bridge. The changes of the natural frequencies for the longitudinal modes remarkably decrease the peak bending moment in the pylon and the movements at the expansion joints. The small changes of the natural frequencies for the vertical modes slightly increase bending moments and deflections in the girder. The original effects of the partially earth-anchored cable system are also shown under wind loads; the decrement of girder axial forces and bearing uplifting forces, and the increment of cable forces in the earth-anchored cables.