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Capacity of Three-Dimensional Erasure Networks [article]

Cheol Jeong, Won-Yong Shin
2016 arXiv   pre-print
In this paper, we introduce a large-scale three-dimensional (3D) erasure network, where n wireless nodes are randomly distributed in a cuboid of n^λ× n^μ× n^ν with λ+μ+ν=1 for λ,μ,ν>0, and completely characterize its capacity scaling laws. Two fundamental path-loss attenuation models (i.e., exponential and polynomial power-law models) are used to suitably model an erasure probability for packet transmission. Then, under the two erasure models, we introduce a routing protocol using percolation
more » ... ghway in 3D space, and then analyze its achievable throughput scaling laws. It is shown that, under the two erasure models, the aggregate throughput scaling n^{1-λ,1-μ,1-ν} can be achieved in the 3D erasure network. This implies that the aggregate throughput scaling n^2/3 can be achieved in 3D cubic erasure networks while √(n) can be achieved in two-dimensional (2D) square erasure networks. The gain comes from the fact that, compared to 2D space, more geographic diversity can be exploited via 3D space, which means that generating more simultaneous percolation highways is possible. In addition, cut-set upper bounds on the capacity scaling are derived to verify that the achievable scheme based on the 3D percolation highway is order-optimal within a polylogarithmic factor under certain practical operating regimes on the decay parameters.
arXiv:1605.03282v1 fatcat:jlmdps2mubfabhppj67ajpon2a

Micromachined lens microstages for two-dimensional forward optical scanning

Hyeon-Cheol Park, Cheol Song, Ki-Hun Jeong
2010 Optics Express  
This work presents a novel approach for a miniaturized optical scanning module based on lateral and piston motion of two commercial lenses by MEMS actuation. Two aspheric glass lenses of 1 mm diameter are assembled on two electrostatically actuated microstages moving along perpendicular axes to tilt optical path. The compact integration secures the effective beam aperture of 0.6 mm within the device width of 2 mm. The lens mass provides high-Q motions at low operating voltages of DC 5 V and AC
more » ... 0 V pp , i.e., the lateral angle of ± 4.6° at 277 Hz and the vertical angle of ± 5.3° at 204 Hz. The device can provide a new direction for miniaturizing laser scanning based endoscopes or handheld projectors.
doi:10.1364/oe.18.016133 pmid:20720998 fatcat:66je73cgbvfijkqkfnvt5xqmqi

Process Simulation of HCNG Refueling System
HCNG 충전 시스템 공정모사

Sang-Min Kim, Jeong-Ok Han, Yeong-Cheol Lee, Joong-Seong Lee, Yong-Cheol Kim, Jeong-Min Chae, Seong-Ho Hong
2013 Journal of the Korean Institute of Gas  
요 약 수소와 압축천연가스가 30 : 70비율로 혼합되는 HCNG 공급 시스템의 공정모사를 수행하였다. 수소 생산은 천 연가스로부터 수증기 개질 공정을 이용하는 방법이며, 수증기 개질반응기 운전조건으로 SCR은 증가할수록 천 연가스의 전환율은 증가하지만 SCR이 3이상부터는 큰 차이가 없었고, GHSV는 증가할수록 연료처리량이 증가 하지만 전환율은 감소하여 1700 h -1 일 때 전환율 및 연료처리량이 최적상태가 되었다. CNG는 저압 천연가스가로 부터 압축되어 공급되는 시스템이다. 혼합용 수소와 천연가스는 고압상태에서 HCNG로 혼합된다. 수소와 천연 가스는 각각 400 bar와 250 bar의 고압으로 압축된다. 고압압축을 위해 단일압축보다 압축소요동력이 적게 사용되 는 다단 압축을 사용하였다. 수소와 천연가스압축에 각각 사용된 압축기들의 압축 총 소요 동력을 최소화하는 중 간 설정압력으로 각각 61 bar, 65 bar의 중간압력을 도출하였다. Abstract -In
more » ... study, simulation work of HCNG refueling system was performed. The hydrogen was produced from steam reforming process by natural gas. The conversion of natural gas is increased as SCR is increased. but it was no significant difference more than 3 of SCR and fuel throughput is increased as GHSV is increased. Both conversion and fuel throughput levels was optimized when the 1700h -1 of GHSV. CNG was compressed from low pressure natural gas. For the mixing of H2 and CNG is mixed with the high pressure conditions such as 400bar of H2 and 250bar of natural gas. Single-stage compression was required more power than multi stage. So, multi stage compression was suggested for high pressure compression. We calculated the intermediate pressure to minimize total required power of compressors. The intermediate pressure for H2 and natural gas were derived at 61 and 65 bar, respectively.
doi:10.7842/kigas.2013.17.5.1 fatcat:wjqotdiqbzb5va25falhudytvm

High Pressure Refueling Method for HCNG Gas Supply
HCNG 가스공급을 위한 고압혼합 충전방안

Sang-Min Kim, Joong-Seong Lee, Jeong-Ok Han, Yeong-Cheol Lee, Yong-Cheol Kim, Jeong-Min Chae, Seong-Ho Hong
2014 Journal of the Korean Institute of Gas  
요 약 수소와 압축천연가스의 혼합연료 HCNG의 가스공급 및 충전을 위해 혼합장치 제작 및 충전실험을 수행하였 다. 비율제어방식 개념으로 수소와 압축천연가스는 30 : 70의 비율로 혼합된다. HCNG 충전방법으로는 탱크의 압 력을 이용하여 충전할 수 있는 FULL충전, 일정량을 충전할 수 있는 정량충전 방식이 있다. Full충전과 정량충전 결과 모두 혼합비율 30 : 70에 오차 제한범위인 수소30±2% 조건을 만족시켰다. 탱크에 충전된 HCNG의 조성을 Gas Chromatography로 분석한 결과도 오차제한범위를 만족시켜 충전탱크에서도 30 : 70의 비율을 확인하였다. Abstract -Mixture of hydrogen and natural gas HCNG mixing equipment production and refueling experiment were performed for supply and product. Hydrogen and CNG in 30 : 70
more » ... tio is mixing of HCNG was performed using ratio control. HCNG refueling method was calculated after reading the pressure of tank for full refuel, amount refuel. Both full refuel and amount refuel results mixed ratio 30 : 70 in the error limits of H2±2% met the criterion. HCNG composition analysis result in refueling tank using gas chromatography is satisfying the error limits in refuel tank 30 : 70 ratio were confirmed.
doi:10.7842/kigas.2014.18.1.25 fatcat:ljkx5rvxuvhljmh7y5mjkl2ude

Comparison of spinal anesthesia between the non-elderly and elderly patients

Sang Yoong Park, Jeong Ho Kim, Jong Cheol Rim, Jeong A Kim, Ji Hyeon Lee, So Ron Choi, Seung Cheol Lee, Jong Hwan Lee, Chan Jong Chung
2016 Anesthesia and Pain Medicine  
The clinical features of spinal anesthesia may differ between young and old patients because of the anatomical and physiological changes that occur with an increase in age. This study was performed retrospectively to compare the clinical aspects of spinal anesthesia between the non-elderly and elderly patients. Methods: We investigated the medical records of 1,180 adult patients who received spinal anesthesia during a one-year period. They were divided into two groups on the basis of 65 years
more » ... age; the non-elderly patient group (Y group, n = 813) versus the elderly patient group (E group, n = 367). Pre-, intra-, and postoperative data related to spinal anesthesia were collected. The data about satisfaction and causes of dissatisfaction with the procedure were evaluated. Results: There were significant differences between the two groups in terms of age, height, and weight, except for sex. Significantly more than two attempts at spinal puncture were performed in the E group (37.6%) than in the Y group (21.4%). There were no statistically significant differences in perioperative complications after spinal anesthesia between the two groups. There were no significant differences in the reported causes of dissatisfaction between the two groups. The rate of wanting to undergo spinal anesthesia in the future was 96.4% in the Y group and 97.5% in the E group, which showed no statistically significant difference. Conclusions: Although the elderly patients had to undergo more spinal puncture attempts, more than 90% of the elderly patients were satisfied with spinal anesthesia and wanted to undergo spinal anesthesia again for similar surgeries in the future. (Anesth Pain Med 2016; 11: 190-194)
doi:10.17085/apm.2016.11.2.190 fatcat:fy2nqlilyvgdhnnojikvsuav7q

Safety of Percutaneous Right Coronary Intervention without Temporary Pacemaker: Prospective Study

Sung Yun Lee, Hyeon Cheol Gwon, Hyun Jung Kim, Jin Ok Jeong, Kyung Ju Ahn, Sang Cheol Lee, Wook Hyun Cho, Seung Woo Park, June Soo Kim, Duk Kyung Kim, Sang Hoon Lee, Kyung Pyo Hong (+3 others)
1999 Korean Circulation Journal  
The prophylactic use of temporary pacemaker during coronary intervention has been markedly decreased since 1980's. There is, however, few systematic report focusing on right coronary intervention in which temporary pacemaker would be most beneficial. Moreover, there has been marked development in coronary intervention recent years that risk and benefit of prophylactic pacemaker should be reconsidered. Method We performed right coronary artery intervention without prophylactic use of temporary
more » ... cemaker in 100 successive patients in Samsung Medical Center. Patients with previous AV block and rotational atherectomy cases were excluded. The incidence of all complications and changes of blood pressure as well as heart rate during coronary intervention were examined prospectively. Results The lesion type was B2 or C in 52% and intracoronary thrombus was found in 18% of patients. Nevertheless, there was neither life threatening bradycardia nor new onset arrhythmia in any patient during right coronary intervention. Conclusion These data suggest that omission of prophylactic use of temporary pacemaker may be safe in right coronary intervention only if excluding previous patients with high degree atrioventricular block and rotational atherectomy cases. This approach may reduce procedure time and cost as well as pacemaker-associated complications. Korean Circulation J 1999 ; 29 11 : 1182-1187 KEY WORDS Coronary intervention·Temporary pacemaker·Safety.
doi:10.4070/kcj.1999.29.11.1182 fatcat:adne4d4wireojob7dnosq5b4uq

Tumor Necrosis Factor and Regulatory T Cells

Min Kyung Jung, Jeong Seok Lee, Jeong-Eun Kwak, Eui-Cheol Shin
2019 Yonsei medical journal  
AUTHOR CONTRIBUTIONS Wrote the first draft of the manuscript: Min Kyung Jung, Jeong Seok Lee, and Jeong-Eun Kwak. Approved the final version: Min Kyung Jung and Eui-Cheol Shin.  ...  ORCID iDs Min Kyung Jung https://orcid.org/0000-0003-2480-9202 Jeong Seok Lee https://orcid.org/0000-0001-8261-7044 Jeong-Eun Kwak https://orcid.org/0000-0003-3178-0823 Eui-Cheol Shin https://orcid.org  ... 
doi:10.3349/ymj.2019.60.2.126 fatcat:yuu7pnrubndibitco6eeemu3xm

Fast Super-Resolution Algorithm Based on Dictionary Size Reduction Usingk-Means Clustering

Shin-Cheol Jeong, Byung Cheol Song
2010 ETRI Journal  
This paper proposes a computationally efficient learning-based super-resolution algorithm using k-means clustering. Conventional learning-based super-resolution requires a huge dictionary for reliable performance, which brings about a tremendous memory cost as well as a burdensome matching computation. In order to overcome this problem, the proposed algorithm significantly reduces the size of the trained dictionary by properly clustering similar patches at the learning phase. Experimental
more » ... s show that the proposed algorithm provides superior visual quality to the conventional algorithms, while needing much less computational complexity. and is currently an assistant professor. His research interests are video coding, video processing, super-resolution, stereo vision, multimedia system design, image coding, content-based multimedia retrieval, and data mining.
doi:10.4218/etrij.10.0109.0637 fatcat:v3da6um3rbb5phm77myqnlv3de

Change of quality characteristics in fresh-cut'Romaine'lettuce by heat treatment

Jeong Mi Bae, Da Uhm Lee, Moon Cheol Jeong, Jeong Hee Choi
2016 Korean Journal of Food Preservation  
This study investigated the effect of heat treatments on the quality characteristics of fresh-cut 'Romaine' lettuce by treating in hot water (45, 50, and 55℃) for 2 minutes. Sensory properties, respiration rate, ethylene production, microbial growth, browning index, total phenolics (TP), vitamin C, and antioxidant properties (DPPH, ABTS, and FRAP assays) of samples were evaluated after 5 days at 5℃. All heat treatment conditions tested in this study did not affect the change in TP after
more » ... Treatment at 45℃ enhanced respiration rate and ethylene production wheres decreased vitamin C content and antioxidant activities. There was no significant difference in browning index at 45℃ treatment. The rapid tissue softening occurred when treated with 55℃ hot water for 2 minutes. The 50℃ heat treatments exhibited the best quality index including texture and color, and inhibited microbial growth and browning after storage. In addition, the 50℃ heat treatment showed the highest vitamin C content and antioxidant activities (DPPH, ABTS, FRAP assay) after storage. Therefore, the 50℃ heat treatment can be used to maintain quality and antioxidant property of fresh-cut 'Romain' lettuce.
doi:10.11002/kjfp.2016.23.1.27 fatcat:ecmfpcwdejdk7diyinuqj5byxu

Platynosomum fastosumInfestation in a Domestic Cat in Korea

Jong Min Kim, Jeong Hwan Che, Doo Hyun Jeong, Byeong Cheol Kang
2010 Laboratory Animal Research  
Cat liver fluke (Platynosomum fastosum) was identified upon necropsy of a Felis catus (domestic cat). This trematode has not been reported in domestic cats previously in Korea. Diagnosis of this fluke was made by the presence of eggs in the feces of the cat through the fecal sedimentation method. Flukes in the gallbladder, bile duct, and liver parenchyma were revealed by the necropsy findings. This report describes as the first case of a domestic cat with Platynosomum fastosum in Korea.
doi:10.5625/lar.2010.26.3.307 fatcat:4x77lg7paze55egyhxlyclmpzu

A study on the oxidation kinetics of ultrathin cobalt films

Won-Cheol Jeong, Chang-Wook Jeong, Seung-Ki Joo
2000 ITE Technical Report  
doi:10.11485/itetr.24.68.0_79 fatcat:ildsfgygzzhvhggan6bjcbysle

Orbital Floor Fracture

Hyo Seong Kim, Eui Cheol Jeong
2016 Archives of Craniofacial Surgery  
INTRODUCTION Fractures of the orbit are common yet challenging to manage. Isolated orbital fractures are encountered in 4%-to-16% of all facial fractures, and orbital fractures compose 30%-55% of zygomatic complex and naso-orbital-ethmoid fractures [1, 2] . Seven facial bones make up the bony orbit: the frontal, maxilla, zygoma, ethmoid, lacrimal, greater and lesser wings of the sphenoid, and palatine bones. The ethmoid, frontal, and maxillary bonesclosely related to sinus pneumatization-act as
more » ... shock absorbers for the eye globe. The outer rim of the orbit is comprised of the first three robust bony elements, protecting the more delicate internal bones of the orbital cavity. The orbital cavity is itself bound by the orbital roof, lateral and medial walls, and orbital floor. The orbital floor, which forms the roof of the maxillary sinus, slopes upward toward the apex of the pyramid, which lies roughly 44 to 50 mm posterior to the orbital entrance [3, 4] . This complicated anatomy makes repair and reconstruction of orbital fracture difficult for a novice (Fig. 1) . Orbital Floor Fracture The medial wall and floor of the bony orbit are frequently fractured because of the delicate anatomy. To optimize functional and aesthetic results, reconstructive surgeons should understand the anatomy and pathophysiology of orbital fractures. Appropriate treatment involves optimal timing of intervention, proper indications for operative repair, incision and dissection, release of herniated tissue, implant material and placement, and wound closure. The following review will discuss the management of orbital floor fractures, with the operative method preferred by the author. Special considerations in operation technique and the complication are also present in this article.
doi:10.7181/acfs.2016.17.3.111 pmid:28913267 pmcid:PMC5556798 fatcat:oh3mocfmhbgwnok544banfgqba

The mediating effect of caregiver burden on the caregivers' quality of life

Yeon-Gyu Jeong, Yeon-Jae Jeong, Won-Cheol Kim, Jeong-Soo Kim
2015 Journal of Physical Therapy Science  
Jeong-Soo Kim (E-mail: suah7475@ hanmail.net) ©2015 The Society of Physical Therapy Science. Published by IPEC Inc.  ... 
doi:10.1589/jpts.27.1543 pmid:26157260 pmcid:PMC4483438 fatcat:6dhxy4wtjrd4pa4luawxgclcjm

Optimization of Temperature Regime to Screen Cold Tolerant Rice Seedlings

Ung-Jo Hyun, Sang-Min Yeo, Sang-Bok Lee, Jeong-Heui Lee, Jong-Min Jeong, Yeaul-Kyu Seong, Dae-Ha Seo, Yong-Jae Won, Eok-Keun Ahn, Jeom Ho Lee, Jun-Cheol Mun, Cheol-Seong Jang
2016 Plant Breeding and Biotechnology  
This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Plant Breed. Biotech. 2016 (May) 4(2):176~187 http://dx. ABSTRACT Low temperature stress at the seedling stage of rice is an important factor causing the leaf discoloration, wilting and
more » ... tly leads to non-uniform crop maturation. In order to screen the cold tolerance elite lines efficiently, the five cold treatment conditions with different water and air temperature were designed and treated at seedling stage. For the evaluation of seedling tolerance, the injury was scored by visual rate and measured by Soil and Plant Analyzer Development (SPAD) meter. In the reactions of varieties for each treatment, the treatment 'B' condition, 12 o C mean water with 24 o C mean air, shows clear discoloration, so it's correlation coefficient was highest (r=−0.9, P<0.0001) among the treatments. In the treatment condition for screening the cold-tolerance elite line, the cultivar, treatment and their interaction significantly affect the SPAD value. The 'A' treatment, 12 o C mean water with 34 o C mean air, was the best way to observe the variation between the elite lines. On the basis of the Duncan's test for SPAD value of cultivars, Keumo (moderate tolerant), Saetbyeol (sensitive) and Seolak (tolerant) were selected as check varieties. To study its impacts at the paddy field, the changes of crop characteristics such as height, panicle length, number of tiller and heading were investigated. In later growth period, the seedling treatment impact at the paddy field leads to heading delay. Due to the low temperature stress at the seedling stage induced by 12 o C mean cold water, Japonica and Tongil group shows the heading delay 4 to 7 and 8 to 11 days respectively.
doi:10.9787/pbb.2016.4.2.176 fatcat:ks5zfdcaf5hijmw352le5e2wqy

Degrees of Freedom of Interference Channels with Hybrid Beam-forming [article]

Sung Ho Chae, Cheol Jeong
2015 arXiv   pre-print
We study the sum degrees of freedom (DoF) of interference channels with hybrid beam-forming in which hybrid beam-forming composed of analog and digital precodings is employed at each node. For the two-user case, we completely characterize the sum DoF for an arbitrary number of antennas and RF chains by developing an achievable scheme optimized for the hybrid beam-forming structure and deriving its matching upper bound. For a general K-user case, we focus on a symmetric case and obtain lower and
more » ... upper bounds on the sum DoF, which are tight for certain cases. The results show that hybrid beam-forming can increase the sum DoF of interference channel under certain conditions while it cannot improve the sum DoFs of point-to-point channel, multiple access channel, and broadcast channel. The key insights on this gain is that hybrid beam-forming enables users to manage inter user interference better, and thus each user can increase the dimension of interference-free signal space for its own desired signals.
arXiv:1504.06743v1 fatcat:lsq66twzkjgvdlb34mibjkclry
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