• Title/Summary/Keyword: LoS

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Performance Analysis of Drone-type Base Station on the mmWave According to Radio Resource Management Policy (무선자원 운용방안에 따른 밀리미터파 대역에서의 드론형 기지국 성능분석)

  • Jeong, Min-Woo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.5
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    • pp.917-926
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    • 2019
  • At present, TICN has been developed and distributed for military command control. TICN is known as the 3.5G mobile communication technology based on WiBro, which shows technical limitation in the field operation situation. Accordingly, the drone-type base station platform is attracting attention as an alternative to overcome technical limitations such as difficulty in securing communication LoS and limiting expeditious network configuration. In this study, we performed simulation performance evaluation of drone-type base station operation in 28 GHz that is considered most suitable for cellular communication within mmWave frequency band. Specifically, we analyzed the changes in throughput and fairness performance according to radio resource management policies such as frequency reuse and scheduling in multi-cell topology. Through this, we tried to provide insights on the operation philosophy on drone-type base station.

Medical Interpreters in Korea: A Qualitative Study of Medical Tourists' Satisfaction and the Role of Interpreters

  • Al-Farajat, Lo'ai Adnan;Jung, Seong-Hoon;Seo, Young-Joon
    • International Journal of Advanced Culture Technology
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    • v.6 no.4
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    • pp.20-28
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    • 2018
  • Background: As a result of the South Korean government's medical tourism strategies, the number of UAE inbound medical tourists have the highest annual increase rate among the Middle Eastern countries. The need for medical interpreters in such cases is inevitable, especially considering the languages spoken in both countries differs. The work of a medical interpreter affects patient satisfaction, quality of care, and the UAE patients' revisit intention. However, there is a lack of literature that focuses on the role of medical interpreters for the Arabic-speaking medical tourists in South Korea. The purpose of this study is to assess the satisfaction and the experience of UAE medical tourists in South Korea who have used medical interpretation services. Method: A descriptive exploratory design, including semi-structured interviews, was used in this study to examine factors influencing the satisfaction of UAE patients seeking medical attention in South Korea, who considered travelling exclusively for medical purposes. Eleven UAE medical tourists were selected for the interview using convenience sampling. Results: Two types of interpreters were revealed by the analysis: interpreters with Arabic as their mother tongue and interpreters with Korean as their mother tongue. Patients emphasized the origin of the interpreters and differentiated between the two types of interpreters' professionalism, abilities, and personal skills. However, due to the huge gap between the two cultures, languages, and religions, the UAE patients mainly preferred the Arabic medical interpreters. Further, each type had certain traits that impacted the medical care process and patients' satisfaction. Conclusion: This study shows that the South Korean government needs to focus on the training and assessment system for Arabic language interpreters. Additionally, cultural differences training for the interpreters may help to increase UEA patients' satisfaction.

Direct analysis of steel frames with asymmetrical semi-rigid joints

  • Chan, Jake L.Y.;Lo, S.H.
    • Steel and Composite Structures
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    • v.31 no.1
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    • pp.99-112
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    • 2019
  • Semi-rigid joints have been widely studied in literature in recent decades because they affect greatly the structural response of frames. In literature, the behavior of semi-rigid joints is commonly assumed to be identical under positive and negative moments which are obviously incorrect in many cases where joint details such as bolt arrangement or placement of haunch are vertically asymmetrical. This paper evaluates two common types of steel frames with asymmetrical beam-to-column joints by Direct Analysis allowing for plasticity. A refined design method of steel frames using a proposed simple forth order curved-quartic element with an integrated joint model allowing for asymmetrical geometric joint properties is presented. Furthermore, the ultimate behavior of six types of asymmetrical end-plate connections under positive and negative moment is examined by the Finite Element Method (FEM). The FEM results are further applied to the proposed design method with the curved-quartic element for Direct Analysis of two types of steel frames under dominant gravity or wind load. The ultimate frame behavior under the two different scenarios are examined with respect to their failure modes and considerably different structural performances of the frames were observed when compared with the identical frames designed with the traditional method where symmetrical joints characteristics were assumed. The finding of this research contributes to the design of steel frames as their asymmetrical beam-to-column joints lead to different frame behavior when under positive and negative moment and this aspect should be incorporated in the design and analysis of steel frames. This consideration of asymmetrical joint behavior is recommended to be highlighted in future design codes.

Tissue Expanders in Staged Calvarial Reconstruction: A Systematic Review

  • Andrea Y. Lo;Roy P. Yu;Anjali C. Raghuram;Michael N. Cooper;Holly J. Thompson;Charles Y. Liu;Alex K. Wong
    • Archives of Plastic Surgery
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    • v.49 no.6
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    • pp.729-739
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    • 2022
  • Cranioplasties are common procedures in plastic surgery. The use of tissue expansion (TE) in staged cranioplasties is less common. We present two cases of cranioplasties with TE and systematically review literature describing the use of TE in staged cranioplasties and postoperative outcomes. A systematic review was performed by querying multiple databases. Eligible articles include published case series, retrospective reviews, and systematic reviews that described use of TE for staged bony cranioplasty. Data regarding study size, patient demographics, preoperative characteristics, staged procedure characteristics, and postoperative outcomes were collected. Of 755 identified publications, 26 met inclusion criteria. 85 patients underwent a staged cranioplasty with TE. Average defect size was 122 cm2, and 30.9% of patients received a previous reconstruction. Average expansion period was 14.2 weeks. The most common soft tissue closures were performed with skin expansion only (75.3%), free/pedicled flap (20.1%), and skin graft (4.7%). The mean postoperative follow-up time was 23.9 months. Overall infection and local complication rates were 3.53 and 9.41%, respectively. The most common complications were cerebrospinal fluid leak (7.1%), hematoma (7.1%), implant exposure (3.5%), and infection (3.5%). Factors associated with higher complication rates include the following: use of alloplastic calvarial implants and defects of congenital etiology (p = 0.023 and 0.035, respectively). This is the first comprehensive review to describe current practices and outcomes in staged cranioplasty with TE. Adequate soft tissue coverage contributes to successful cranioplasties and TE can play a safe and effective role in selected cases.

A Study on the Management System Design for Technical Information of the Weapon Embedded Software (무기체계 내장형 소프트웨어 기술정보 관리실태 분석을 통한통합관리체계 설계에 관한 연구)

  • Kim, Sei-Il;Kim, Hyo-Sung;Lee, Il-Lo
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.11
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    • pp.123-134
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    • 2009
  • As the embedded software for weapon system is embossed, the information management system is required to service and manage the technical information of embedded software systematically. But the technical information documents are managed by its own organization separately, it's hard to service the information and share it with anyone who need. In this paper, to manage the embedded software information systematically, we analyze the information management system built in 2004 and the defence law/rule. Also we distinguish the software information from defence laws to manage systematically and analyze the requirements of the information system. Based on these, we suggest implementing the management system to increase efficiency of managing the weapon embedded software information. Through this, we can improve the utilization and reusability of the weapon embedded software.

Relationship between disk displacement of temporomandibular joint and dentofacial asymmetry (측두하악관절 원판 변위와 치열 및 안면부 비대칭의 관계에 대한 연구)

  • Nahm, Kyoung-Soo;Kim, Tae-Woo
    • The korean journal of orthodontics
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    • v.33 no.3 s.98
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    • pp.211-222
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    • 2003
  • The purpose of this study was to determine whether there is an association between disk displacement of the Temporomandibular Joint (TMJ) and dentofacial asymmetry In orthodontic patients. The subjects consisted of 60 female orthodontic patients between the ages of 18 and 38 years (mean age 23.3 years) who had visited the Department of Orthodontics at Seoul National University Dental Hospital from January 2000 to April 2002. On the basis of magnetic resonance imaging (MRI) of their bilateral TMJs, the subjects were divided Into four groups'. bilateral normal group (twenty-one persons); disk displacement of right TMJ group (six persons); disk displacement of left TMJ group (nine persons); and disk displacement of both TMJs group (twenty-four persons) Postero-anterior (PA) cephalograms and diagnostic models which had been taken before orthodontic treatment were measured. In the linear measurements, a line connecting the right and left Latero-Orbitale (Lo) represented the horizontal reference line (H). The vertical reference line (V) was constructed as a line bisecting and running perpendicular to H. One-way analysis of variance (ANOVA) was used to test whether the mean values of measurements between groups were significantly different. In addition, Bonferronil's multiple comparison test was performed at a level of 0.05. The results were as follows; 1 In the diagnostic model analysis, the overjet, nght molar relationship, and left molar relationship were significantly different among the four groups. 2. In the PA cephalometric analysis, differences in the right and left vertical position of the lower first molar and Ag were significantly dissimilar among the four groups. 3. If the disk displacement of TMJ was present on one side, the ipsilateral ramus was shorter, resulting in asymmetry in the vertical position of Ag. This study indicated that dentofacial asymmetry might be related to the disk displacement of TMJ.

Characteristics of Phytoplankton Succession Based on the Functional Group in the Enclosed Culture System (대형 배양장치에서 기능그룹에 기초한 식물플랑크톤 천이 특성)

  • Lee, Kyung-Lak;Noh, Seongyu;Lee, Jaeyoon;Yoon, Sungae;Lee, Jaehak;Shin, Yuna;Lee, Su-Woong;Rhew, Doughee;Lee, Jaekwan
    • Korean Journal of Ecology and Environment
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    • v.50 no.4
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    • pp.441-451
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    • 2017
  • The present study was conducted from August to December 2016 in a cylindrical water tank with a diameter of 1 m, a height of 4 m and a capacity of 3,000 L. The field water and sediment from the Nakdong River were also sampled for the experimental culture (field water+sediment) and control culture (field water), respectively. In this study, we aimed to investigate phytoplankton succession pattern using the phytoplankton functional group in the enclosed culture system. A total of 50 species in 27 genera including Chlorophyceae (30 species), Bacillariophyceae (11 species), Cyanophyceae (7 species), and Cryptophyceae (2 species) were identified in the experimental and control culture systems. A total of 19 phytoplankton functional groups (PFGs) were identified, and these groups include B, C, D, F, G, H1, J, K, Lo, M, MP, N, P, S1, $T_B$, $W_0$, X1, X2 and Y. In particular, $W_0$, J and M groups exhibited the marked succession in the experimental culture system with higher biovolumes compared to those of the control culture system, which may be related to the internal cycling of nutrients by sediment in the experimental culture system. The principal component analyses demonstrated that succession patterns in PFG were associated with the main environmental factors such as nutrients(N, P), water temperature and light intensity in two culture systems. In conclusion, the present study showed the potential applicability of the functional group for understanding the adaptation strategies and ecological traits of the phytoplankton succession in the water bodies of Korea.

Effect of Boswellia serrata Extracts on Degenerative Osteoarthritis in vitro and in vivo Models (보스웰리아 추출물의 골관절염 억제 효과 연구)

  • Nam, Da-Eun;Kim, Ok Kyung;Shim, Tae Jin;Kim, Ji Hoon;Lee, Jeongmin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.5
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    • pp.631-640
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    • 2014
  • The inhibitory effects of Boswellia serrata (BW) extracts on degenerative osteoarthritis were investigated in primary-cultured rat cartilage cells and a monosodium-iodoacetate (MIA)-induced osteoarthritis rat model. To identify the protective effects of BW extract against $H_2O_2$ ($800{\mu}M$, 2 hr) in vitro, cell survival was measured by MTT assay. Cell survival after $H_2O_2$ treatment was elevated by BW extract at a concentration of $20{\mu}g/mL$. In addition, BW extract treatment significantly reduced and normalized the productions of pro-inflammatory factors, nuclear transcription factor ${\kappa}B$, cyclooxygenase-2, tumor necrosis factor-${\alpha}$, and interleukin-6 at a concentration of $20{\mu}g/mL$. Treatment of chondrocytes with BW extract significantly reduced 5-lipoxygenase activity and production of prostaglandin E2, especially at a concentration of $10{\sim}20{\mu}g/mL$. For the in vivo animal study, osteoarthritis was induced by intra-articular injection of MIA into knee joints of rats. Consumption of a diet containing BW extract (100 and 200 mg/kg) for 35 days significantly inhibited the development and severity of osteoarthritis in rats. To determine the genetic expression of arthritic factors in articular cartilage, real-time PCR was applied to measure matrix metalloproteinases (MMP-3, MMP-9, and MMP-13), collagen type I, collagen type II, and aggrecan, and BW extract had protective effects at a concentration of 200 mg/kg. In conclusion, BW extract was able to inhibit articular cartilage degeneration by preventing extracellular matrix degradation and chondrocyte injury. One can consider that BW extract may be a potential therapeutic treatment for degenerative osteoarthritis.

Increase of Salt and Low Temperature Tolerance by Overexpressing Glutathione S-Transferase (GST) Gene (염분과 저온에 대한 내성증진을 위한 GST 유전자의 과발현)

  • Jun Chol Kim;Il Seop Kim;Won Hee Kang
    • Journal of Bio-Environment Control
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    • v.11 no.3
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    • pp.139-143
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    • 2002
  • Cotton Glutathione S-Transferase (GST: EC 2.5.1.18) was cloned and overexpressed in tobacco (Nicotiana tabacum) plants. Northern blot analysis confirmed the successful transformation of cotton gst gene in tobacco plant. Type I and Type ll transcript patterns were identified in transgenic tobacco plants and only Type I transcripts were discussed in this paper, The activity of GST in the type II transgenic plants was about 1.5-fold higher than those of the wild type and non-expresser by using 1-chloro-2,4-dinitrobenzene (CDNB) and reduced glutathione as the substrate. The expression of cotton GST in tobacco plants proved that Gh-5 could be translated into functional protein. Type II transgenic plants produced functional GST in the cells. The effects of cotton GST in the seedlings was evaluated by growing the control and transgenic seedlings at $15^{\circ}C$ in the growth chamber in the light. Overexpressors were grown well compared to the control plants (non-expressors). lo test far tolerance to salinity, seeds of Gh-5 overexpressors and the wild type Xanthi seedlings were grown at 0, 50, 100, 150, and 200 mM NaCl solution. Gh-5 transgenic seedlings showed higher growth rate over control seedlings on 50 and 100 mM NaCl solution. There was no difference in growth rate at 150 and 200mM NaCl concentration.

Design and fabrication of the MMIC frequency doubler for 29 GHz local oscillator application (29GHz 국부 발진 신호용 MMIC 주파수 체배기의 설계 및 제작)

  • Kim, Jin-Sung;Lee, Seong-Dae;Lee, Bok-Hyoung;Kim, Sung-Chan;Sul, Woo-Suk;Lim, Byeong-Ok;Kim, Sam-Dong;Park, Hyun-Chang;Park, Hyung-Moo;Rhee, Jin-Koo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.38 no.11
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    • pp.63-70
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    • 2001
  • We demonstrate the MMIC (monolithic microwave integrated circuit) frequency doublers generating stable and low-cost 29 GHz local oscillator signals from 14.5 GHz input signals. These devices were designed and fabricated by using the M MIC integration process of $0.1\;{\mu}m$ gate-length PHEMTs (pseudomorphic high electron mobility transistors) and passive components. The measurements showed S11 or -9.2 dB at 145 GHz, S22 of -18.6 dG at 29 GHz and a minimum conversion loss of 18.2 dB at 14.5 GHz with an input power or 6 dBm. Fundamental signal of 14.5 GHz were suppressed below 15.2 dBe compared to the second harmonic signal at the output port, and the isolation characteristics of fundamental signal between the input and the output port were maintained above :i0 dB in the frequency range 10.5 GHz to 18.5 GHz. The chip size of the fabricated MMIC frequency doubler is $1.5{\times}2.2\;mm^2$.

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