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Estimation of Turbulent Sensible Heat and Momentum Fluxes over a Heterogeneous Urban Area Using a Large Aperture Scintillometer

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Advances in Atmospheric Sciences 2015年第8期32卷 1092-1105页

作者： Sang-Hyun lee jun-ho lee Bo-Young KIM Department of Atmospheric Science Kongju National University Department of Optical Engineering Kongju National University

The accurate determination of surface-layer turbulent fluxes over urban areas is critical to understanding urban boundary layer （UBL） evolution. In this study, a remote-sensing technique using a large aperture scintillometer （LAS） was investigated to estimate surface-layer turbulent fluxes over a highly heterogeneous urban area. The LAS system, with an optical path length of 2.1 km, was deployed in an urban area characterized by a complicated land-use mix （residential houses, water body, bare ground, etc.）. The turbulent sensible heat （QH） and momentum fluxes （z） were estimated from the scintillation measurements obtained from the LAS system during the cold season. Three-dimensional LAS footprint modeling was introduced to identify the source areas （＂footprint＂） of the estimated turbulent fluxes. The analysis results showed that the LAS-derived turbulent fluxes for the highly heterogeneous urban area revealed reasonable temporal variation during daytime on clear days, in comparison to the land-surface process-resolving numerical modeling. A series of sensitivity tests indicated that the overall uncertainty in the LAS-derived daytime QH was within 20%-30% in terms of the influence of input parameters and the non- dimensional similarity function for the temperature structure function parameter, while the estimation errors in z were less sensitive to the factors of influence, except aerodynamic roughness length. The 3D LAS footprint modeling characterized the source areas of the LAS-derived turbulent fluxes in the heterogeneous urban area, revealing that the representative spatial scales of the LAS system deployed with the 2.1 km optical path distance ranged from 0.2 to 2 km2 （a ＂micro-a scale＂）, depending on local meteorological conditions.

关键词： heterogeneous surface large aperture scintillometer mesoscale modeling surface energy balance turbulentexchange

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Gastric cancer surgery in cirrhotic patients: Result of gastrectomy with D2 lymph node dissection

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World Journal of Gastroenterology 2005年第30期11卷 4623-4627页

作者： jun ho lee junuk Kim Jae ho Cheong Woo Jin Hyung Seung ho Choi Sung hoon Noh Research Institute and hospital Department of Surgery

AIM： To explore the feasibility of performing gastrectomy with D2 lymphadenectomy in gastric cancer patients with liver cirrhosis. METhoDS： A total of 7 178 patients were admitted with a diagnosis of liver cirrhosis from January 1993 to December 2003. We reviewed the records of 142 patients who were diagnosed with liver cirrhosis and gastric adenocarcinoma during the same period. Gastrectomy with D2 lymph node dissection for carcinoma of the stomach was performed in 94 patients with histologically proven hepatic cirrhosis. RESULTS： All but 12 patients were dassified as Child＇s class A. Only 35 patients （37.2%） were diagnosed with cirrhosis before operation. Seventy-three patients underwent a subtotal gastrectomy （77.7%） and 21 patients （22.3%） underwent a total gastrectomy, each with D2 or more lymph node dissection. Two patients （3.8%） who had prophylactic intra-operative drain placement, died of postoperative complications from hepatorenal failure with intractable ascites. Thirty-seven patients （39.4%） experienced postoperative complications. The extent of gastric resection did not influence the morbidity whereas serum aspartate aminotransferase level （P = 0.011） and transfusion did （P = 0.008）. The most common postoperative complication was ascites （13.9%） followed by wound infection （10.6%）. CONCLUSION： We concluded that the presence of compensated cirrhosis, i.e. Child class A, is not a contraindication against gastrectomy with D2 or more lymph node dissection, when curative resection for gastric cancer is possible. Hepatic reserve and meticulous hemostasis are the likely determinants of operative prognosis.

关键词： Gastric cancer Liver cirrhosis D2 lymph nodedissection Morbidity Mortality

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Comparative study on discharge conditions in micro-hole electrical discharge machining of tungsten carbide (WC-Co) material

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中国有色金属学会会刊：英文版 2009年第B9期19卷 114-118页

作者： Hyun-Seok TAK Chang-Seung HA Dong-Hyun KIM ho-jun lee Hae-june lee Myung-Chang KANG National Core Research Center for Hybrid Materials Solution Pusan National University Department of Electrical Engineering Pusan National University

WC-Co is used widely in die and mold industries due to its unique combination of hardness, strength and wear-resistance. For machining difficult-to-cut materials, such as tungsten carbide, micro-electrical discharge machining(EDM) is one of the most effective methods for making holes because the hardness is not a dominant parameter in EDM. This paper describes the characteristics of the discharge conditions for micro-hole EDM of tungsten carbide with a WC grain size of 0.5 μm and Co content of 12%. The EDM process was conducted by varying the condenser and resistance values. A R-C discharge EDM device using arc erosion for micro-hole machining was suggested. Furthermore, the characteristics of the developed micro-EDM were analyzed in terms of the electro-optical observation using an oscilloscope and field emission scanning electron microscope.

关键词：电火花加工碳化钨钴难切削材料硬质合金放电扫描电子显微镜微孔模具行业

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Characteristic evaluation of Al_2O_3/CNTs hybrid materials for micro-electrical discharge machining

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 28-32页

作者： Hyun-Seok TAK Chang-Seung HA ho-jun lee Hyung-Woo lee Young-Keun JEONG Myung-Chang KANG National Core Research Center for Hybrid Materials Solution Pusan National University Department of Electrical Engineering Pusan National University

The characteristic evaluation of aluminum oxide （A1203）/carbon nanotubes （CNTs） hybrid composites for micro-electrical discharge machining （EDM） was described. Alumina matrix composites reinforced with CNTs were fabricated by a catalytic chemical vapor deposition method. A1203 composites with different CNT concentrations were synthesized. The electrical characteristic of A1203/CNTs composites was examined. These composites were machined by the EDM process according to the various EDM parameters, and the characteristics of machining were analyzed using field emission scanning electron microscope （FESEM）. The electrical conductivity has a increasing tendency as the CNTs content is increased and has a critical point at 5% A1203 （volume fraction）. In the machining accuracy, many tangles of CNT in A1203/CNTs composites cause violent spark. Thus, it causes the poor dimensional accuracy and circularity. The results show that conductivity of the materials and homogeneous distribution of CNTs in the matrix are important factors for micro-EDM of A1203/CNTs hybrid composites.

关键词： A1203/CNTs hybrid materials micro-electrical discharge machining micro-hole electrical conductivity

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Reduction of gastrointestinal motility by unilateral thyroparathyroidectomy plus subdiaphragmatic vagotomy in rats

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World Journal of Gastroenterology 2012年第33期18卷 4570-4577页

作者： jun ho lee Oh Deog Kwon Seon ho Ahn Keun Han Choi Ji Hye Park Seoul lee Bong Kyu Choi Kyu Yong jung Department of Pharmacology Wonkwang University School of Medicine Jeonbuk 570-749 South Korea Department of Clinical Pathology College of Veterinary Medicine Kyungpook National University Daegu 702-701 South Korea Department of Internal Medicine Wonkwang University School of Medicine Jeonbuk 570-749 South Korea

AIM: To investigate whether the combined methods of unilateral thyroparathyroidectomy (TPX) and subdiaphragmatic vagotomy (VAX) can be adapted for rats and used as a reliable method to produce a rat model of long-term reduction of gastrointestinal (GI) motor function. METhoDS: Male Sprague-Dawley rats were randomly divided into 3 groups, normal, sham-operated and unilateral TPX plus VAX. The TPX plus VAX rats received VAX 7 d after application of TPX, and dietary intake and fecal output were then measured daily for 1 *** completion of the experiments, gastric emptying and small bowel transit were measured in vivo, and the contractile responses of colonic strips to excitatory and inhibitory neurotransmitters were estimated using isometric force transducers in vitro. RESULTS: In comparison with normal and sham-operated rats, rats which received unilateral TPX plus VAX showed a significant decrease in body weight and in fecal pellet number and weight throughout the entire week. Application of TPX plus VAX to rats markedly delayed gastric emptying and small bowel transit. In TPX plus VAX rats, the longitudinal muscles of the proximal colon showed a significant reduction in contractile responses to acetylcholine (5 × 10-6 mol/L), and a dramatic attenuation of contractile responses was also observed in both the longitudinal and circular muscles of the distal colon. however, the spontaneous contractility of the colonic strips from TPX plus VAX rats was not significantly affected by treatment with N-nitro-Larginine-methyl ester (0.1 mol/L). CONCLUSION: The results indicate that unilateral TPX plus VAX reduced the motor function of the GI tract in rats, and the reduced gut motility is likely mediated, at least in part, by inhibition of the excitatory neurotransmitter system.

关键词： Unilateral thyroparathyroidectomy Subdiaphragmatic vagotomy Gastric emptying Small bowel transit Rat

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Development of vehicle-recognition method on water surfaces using LiDAR data:SPD^(2)(spherically stratified point projection with diameter and distance)

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Defence Technology（防务技术） 2024年第6期36卷 95-104页

作者： Eon-ho lee Hyeon jun Jeon Jinwoo Choi Hyun-Taek Choi Sejin lee The Department of Mechanical Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea Ocean System Engineering Research Division Korea Research Institute of Ships and Ocean Engineering(KRISO)Daejeon 34103Republic of Korea The Division of Mechanical&Automotive Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea

Swarm robot systems are an important application of autonomous unmanned surface vehicles on water *** monitoring natural environments and conducting security activities within a certain range using a surface vehicle,the swarm robot system is more efficient than the operation of a single object as the former can reduce cost and save *** is necessary to detect adjacent surface obstacles robustly to operate a cluster of unmanned surface *** this purpose,a LiDAR(light detection and ranging)sensor is used as it can simultaneously obtain 3D information for all directions,relatively robustly and accurately,irrespective of the surrounding environmental *** the GPS(global-positioning-system)error range exists,obtaining measurements of the surface-vessel position can still ensure stability during platoon *** this study,a three-layer convolutional neural network is applied to classify types of surface *** aim of this approach is to redefine the sparse 3D point cloud data as 2D image data with a connotative meaning and subsequently utilize this transformed data for object classification ***,we have proposed a descriptor that converts the 3D point cloud data into 2D image *** use this descriptor effectively,it is necessary to perform a clustering operation that separates the point clouds for each *** developed voxel-based clustering for the point cloud ***,using the descriptor,3D point cloud data can be converted into a 2D feature image,and the converted 2D image is provided as an input value to the *** intend to verify the validity of the proposed 3D point cloud feature descriptor by using experimental data in the ***,we explore the feasibility of real-time object classification within this framework.

关键词： Object classification Clustering 3D point cloud data LiDAR(light detection and ranging) Surface vehicle

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Interactive effect of dietary vitamin E and inorganic mercury on growth performance and bioaccumulation of mercury in juvenile olive flounder, Paralichthys olivaceus treated with mercuric chloride

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Animal Nutrition 2017年第3期3卷 276-283页

作者： Mohammad Moniruzzaman jun-ho lee Jin-Hyeok lee Seonghun Won Jim H.Damusaru Sungchul C.Bai Department of Marine Bio-materials and Aquaculture Feeds & Foods Nutrition Research CenterPukyong National University

A 6-week feeding trial was carried out to evaluate the effects of dietary vitamin E(DL-a-tocopheryl acetate, TA) on growth and mercury(Hg) accumulation in juvenile olive flounder(Paralichthys olivaceus)treated with mercuric chloride(HgCl_2). Vitamin E and HgCl_2 were added to the semi-purified basal *** semi-purified diets in a 2 × 3 factorial design were formulated to contain 2 levels of Hg(0 or 20 mg HgCl_2/kg diet) and 3 levels of vitamin E(0, 100, or 200 mg TA/kg diet). Experimental fish(n = 360,9.99 ± 0.15 g) were randomly allocated into 30-L tanks at a density of 20 fish per tank with 3 replicates in each treatment and were fed twice a day. At the end of the feeding trial, dietary Hg depressed the growth performances in terms of weight gain(WG), specific growth rate(SGR), feed efficiency(FE) and protein efficiency ratio(PER) in fish, while fish fed the diets supplemented with vitamin E showed significant growth improvement in both presence and absence of HgCl_2 in the diets(P hole body compositions of fish such as lipid and moisture contents were influenced by dietary vitamin E supplementation. Total Hg contents of muscle, liver and kidney tissues were significantly reduced in fish fed diets supplemented with vitamin E(Phowed that increasing Hg concentration has resulted in a reduction in vitamin *** body fatty acids of fish like eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) contents were decreased by dietary Hg. however, supplementation of dietary vitamin E improved the a-linolenic acid(ALA) and EPA contents in fish. Our results suggest that dietary supplementation of vitamin E has potential effects on growth improvement and ameliorating inorganic Hg bioaccumulation in juvenile olive flounder.

关键词： Vitamin E Mercury Growth Bioaccumulation Olive flounder

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A Study on the Levitation Control of the Multi-degrees-of-Freedom Rotational Machine Supported by Magnetic Bearings Using Flux Feedback

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Journal of Mechanics Engineering and Automation 2014年第6期4卷 533-541页

作者： jun-ho lee Advanced Traction and Noncontact Feeding System Research Team Korea Railroad Research Institute Uiwang-City Gyeonggi-do437-757 Korea

This paper deals with an open-loop characteristic of a magnetically levitated system including flux feedback. In order to design a controller to obtain a good disturbance rejection and to be insensitive to parameter variations, it might be useful to employ a flux feedback loop. The air gap flux which can be sensed by a proper sensor has linear relationship with respect to the change of the current and the air gap. This linear property decreases the inherent nonlinearity of the magnetic suspension system that is caused by the coupling between the electrical actuator and the mechanical plant. Simulation results achieved from a multi-degree-of-freedom numerical model show that the flux feedback loop makes an improvement of the performance of the magnetic suspension system against the load variations.

关键词： Flux feedback magnetic bearings levitation rotational machine multi-degrees-of-freedom

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An Apparatus Design for the Vehicle Control Scheme in Personal Rapid Transit System

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Journal of Mechanics Engineering and Automation 2013年第5期3卷 325-333页

作者： jun-ho lee Advanced Traction and Noncontact Feeding System Research Team Korea Railroad Research Institute Gyeonggi-do Uiwang-City437-757 Korea

A new transportation technology known as personal rapid transit （PRT） is being developed by multiple different companies around the world, and one system is under commercial operations in the United Kingdom. Each design is different, but they all share a need to operate many automated transit vehicles at very close headways. Safe operation will require a level of control an order of magnitude above any current transit system. As a result, new techniques will be needed for the development and testing of the mechanical and control systems. In this paper an apparatus for developing and testing a PRT vehicle control scheme is demonstrated. This system is composed of independent modules that represent virtual vehicles, a central control system, a man-machine interface and a monitoring device. It can be used to implement and to evaluate the designed vehicle control algorithm. The vehicle control algorithm is designed and simulated in a combined simulation platform that consists of Matlab/Simulink and Labview Simulation Interface Toolkit. Simple operational scenarios are proposed for the testing of the proposed vehicle control apparatus.

关键词： Personal rapid transit vehicle control scheme virtual vehicles safe operation headway.

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Oncological safety of use of ultrasonic activated shears in gastric cancer surgery: Long-term results of randomized controlled trial

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Chinese Journal of Cancer Research 2018年第5期30卷 492-499页

作者： Su Mi Kim Jae-Moon Bae Min-Gew Choi jun ho lee Tae Sung Sohn Sung Kim Department of Surgery Samsung Medical Center Sungkyunkwan University School of Medicine

Objective： Ultrasonically activated shears （UAS） have been applied in open gastric surgeries with no or little evidence. It was previously reported about the surgical outcome and effectiveness of UAS based on a randomized controlled trial of 256 patients with gastric cancer. We aimed to clarify the long-term oncological safety of the use of UAS in the aspect of overall survival and ***： Gastric cancer patients who underwent gastrectomy with D2 lymph node dissection were enrolled and randomly assigned to either the conventional surgery group （n=125） or the UAS group （n=128）. Survival, recurrence and long-term postoperative complications were compared between the two groups. The median follow-up period was 56 ***： Gastric cancer-related death was higher in patients of the UAS group compared with the conventional group （P=0.019）. Overall survival rates stratified by stage were not significantly different between the two groups （P=0.170）. Disease-free survival rates stratified by stage and recurrence-free survival rates of gastric cancer were similar between the conventional group and the UAS group （P=0.313 and 0.199, respectively）. The postoperative complication rate was not significantly different between the groups （P=1.000）. Conclusions： It is suggested that the use of UAS in gastrectomy for gastric cancer showed oncologically acceptable safety compared with conventional electric instruments even in long-term period.

关键词： Stomach cancer gastrectomy ultrasonically activated shears (UAS) oncological safety

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