• Advanced Composite Materials
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• 제17권1호
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• pp.25-40
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• 2008

The research and development in soundproof materials for preventing noise have attracted great attention due to their social impact. Noise insulation materials are especially important in the field of soundproofing. Since the insulation ability of most materials follows a mass rule, the heavy weight materials like concrete, lead and steel board are mainly used in the current noise insulation materials. To overcome some weak points in these materials, fiber reinforced composite materials with lightweight and other high performance characteristics are now being used. In this paper, innovative insulation sheet materials with carbon and/or glass fabrics and nano-silica hybrid PU resin are developed. The parameters related to sound performance, such as materials and fabric texture in base fabric, hybrid method of resin, size of silica particle and so on, are investigated. At the same time, the wave analysis code (PZFlex) is used to simulate some of experimental results. As a result, it is found that both bundle density and fabric texture in the base fabrics play an important role on the soundproof performance. Compared with the effect of base fabrics, the transmission loss in sheet materials increased more than 10 dB even though the thickness of the sample was only about 0.7 mm. The results show different values of transmission loss factor when the diameters of silica particles in coating materials changed. It is understood that the effect of the soundproof performance is different due to the change of hybrid method and the size of silica particles. Fillers occupying appropriate positions and with optimum size may achieve a better effect in soundproof performance. The effect of the particle content on the soundproof performance is confirmed, but there is a limit for the addition of the fillers. The optimization of silica content for the improvement of the sound insulation effect is important. It is observed that nano-particles will have better effect on the high soundproof performance. The sound insulation effect has been understood through a comparison between the experimental and analytical results. It is confirmed that the time-domain finite wave analysis (PZFlex) is effective for the prediction and design of soundproof performance materials. Both experimental and analytical results indicate that the developed materials have advantages in lightweight, flexibility, other mechanical properties and excellent soundproof performance.

• 한국정보통신학회논문지
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• 제26권11호
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• pp.1577-1585
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• 2022

최근 4차산업혁명과 함께 메타버스에 대한 관심이 증가하는 가운데, 메타버스를 구축하는 멀티 에지 기반의 구조가 제시된다. 메타버스는 멀티 에지 시스템에서 많은 양의 영상처리와 데이터 전송을 통해 디지털 의사와 같은 시스템을 만들어 낼 수 있는 구조이다. 하지만 에지는 부족한 연산능력이라는 제약이 있으므로, 런타임 스트리밍이 가능한 서비스제공을 위해서는, 에지에서만 이루어졌던 영상처리와 데이터 전송을 에지-클라우드 협동을 통해 처리하여 저전력 시스템을 구축해야한다. 많은 에지들이 연결되는 시스템에서는, 그 무엇보다도 에지 경량화를 통해 효율적인 전체 시스템의 경량화 및 소모전력의 감소를 이루어낼 수 있다. 본 논문에서는 원격영상 처리방법과 Region of Interest (RoI) 기법을 사용하여, AI 소프트웨어의 저전력 런타임 스트리밍이 가능해지는, 에지-클라우드 협동 메타버스 애플리케이션을 제안한다. 에지-클라우드 협동 메타버스의 구조는 PC와 임베디드 보드를 사용하여 구현하였으며, 본 논문의 후반부에서는 에지의 시간 감소와 그에따른 전력 소모, 네트워크 통신량 감소를 검증하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1022-1027
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• 2003

The Motion controllers provide the sophisticated performance and enhanced capabilities we can see in the movements of robotic systems. Several types of motion controllers are available, some based on the kind of overall control system in use. PLC (Programmable Logic Controller)-based motion controllers still predominate. The many peoples use MCU (Micro Controller Unit)-based board level motion controllers and will continue to in the near-term future. These motion controllers control a variety motor system like robotic systems. Generally, They consist of large and complex circuits. PLC-based motion controller consists of high performance PLC, development tool, and application specific software. It can be cause to generate several problems that are large size and space, much cabling, and additional high coasts. MCU-based motion controller consists of memories like ROM and RAM, I/O interface ports, and decoder in order to operate MCU. Additionally, it needs DPRAM to communicate with host PC, counter to get position information of motor by using encoder signal, additional circuits to control servo, and application specific software to generate a various velocity profiles. It can be causes to generate several problems that are overall system complexity, large size and space, much cabling, large power consumption and additional high costs. Also, it needs much times to calculate velocity profile because of generating by software method and don't generate various velocity profiles like arbitrary velocity profile. Therefore, It is hard to generate expected various velocity profiles. And further, to embed real-time OS (Operating System) is considered for more reliable motion control. In this paper, the structure of chip-based precision motion controller is proposed to solve above-mentioned problems of control systems. This proposed motion controller is designed with a FPGA (Field Programmable Gate Arrays) by using the VHDL (Very high speed integrated circuit Hardware Description Language) and Handel-C that is program language for deign hardware. This motion controller consists of Velocity Profile Generator (VPG) part to generate expected various velocity profiles, PCI Interface part to communicate with host PC, Feedback Counter part to get position information by using encoder signal, Clock Generator to generate expected various clock signal, Controller part to control position of motor with generated velocity profile and position information, and Data Converter part to convert and transmit compatible data to D/A converter.

• 한국ITS학회 논문지
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• 제10권5호
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• pp.1-13
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• 2011

현재 DSRC(Dedicated Short Range Communication)를 이용한 통행료자동요금징수시스템이 전국 영업소에 구축 되면서 많은 차량용 단말기가 보급되었다. 이러한 통행료자동요금징수시스템 및 차량용 단말기의 인프라를 이용한 교통정보 수집 및 제공, 신호제어, 대중교통정보제공 및 관리 등 다양한 분야의 ITS 서비스를 위한 연구개발 및 사업화가 추진 중에 있다. 특히 차량용 단말기와 통행료자동지불시스템에 사용되는 노변장치를 이용한 교통정보 수집 및 제공 부분에 많은 연구가 이루어지고 있지만 DSRC의 응용 부분 표준과 교통정보 수집 및 제공을 위한 정보교환 표준이 명확하게 이루어지지 않았다. 이에 국토해양부에서 고시한 "기본교통정보교환 기술기준IV"를 DSRC 통신에서 교환되는 Action 프리미티브를 활용해 DSRC관련 표준의 수정 없이 표준화된 교통정보를 수집 및 제공하는 방안을 제안하고자 한다. 본 연구에서 제안하는 표준적용방안을 현재 ETCS(Electronic Toll Collection System)에서 사용되는 RSE(Road Side Equipment)와 OBE에 적용하여, 실제 도로에서 4대의 차량을 이용한 다양한 주행시험을 통해 시스템의 유효성 및 성능을 확인 하였다. 도로 주행시험 결과 약 97%의 통신 성공률을 통해 본 논문에서 제안한 표준 적용 방안의 유효성을 확인하였고, 약 3%의 실패를 통해 교통정보와 그 외 서비스 부분의 적용을 위해 발생할 수 있는 문제점을 분석하였다.

• 한국임상약학회지
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• 제26권4호
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• pp.318-323
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• 2016

Background: Multidisciplinary team care (MTC) is a collaborative approach to treatment plan and ongoing care. We aimed to evaluate the clinical effect of MTC on the regulation of chronic kidney disease-mineral and bone disorder (CKD-MBD) complications in dialysis patients. Methods: This retrospective observational study was approved by the institutional review board. Among patients who have undergone dialysis at admission, the patients admitted to the nephrology ward were allocated to MTC group, and the others to usual care (UC) group. The MTC group had collaborative care by nephrologists, nurses, pharmacists, and nutritionists. The endpoints were the regulation of corrected calcium (cCa) and phosphate (P), the percent of patients in target level of cCa-P product ($cCa{\times}P$), and the prescription rate of non-calcium based P-binders. Results: A total of 163 patients were included from January to December 2009. A significant difference was shown in the percentage of patients in target $cCa{\times}P$ level at admission (MTC vs. UC, 81.40% vs. 91.67%; P = 0.038), but there was no significant difference at discharge. During admission, the cCa and P levels of patients in only UC group were significantly changed. In addition, compared with UC group, patients in MTC group were more likely prescribed appropriate P-binders, when they had higher $cCa{\times}P$ levels than $55mg^2/dL^2$ (P <0.001). Conclusion: It was found that MTC had beneficial effect on improving the regulation of CKD-MBD and the appropriate phosphate binder uses. Therefore, application of the MTC is anticipated to enhance quality of clinical care in chronic diseases.

• 대한수의학회지
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• 제31권4호
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• pp.491-500
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• 1991

This study was conducted to detect the serum antibodies in the experimentally toxoplasma infected dogs and street dogs by use the of an enzyme-linked immunosorbent assay (ELISA). And this test was performed on the polystylene microplate by coating with the tachyzoites soluble antigen of T gondii (RH strain), incubated with sera diluted then, added with HPO-conjugated rabbit anti-dog IgG and o-phenylenediamine used as a substrate. Tachyzoites of T gondii harvested from mouse peritoneal cavity were purified by 30, 40 and 50% Percoll density gradient centrifugation and used as the source of antigen. The results obtained were summarized as follows; 1. The highest ratio of positive to negative (P/N ratio) was obtained at the level of $l{\mu}g/ml$ protein concentration of antigen with the 1/4000 dilution of the conjugate measured by checker-board titration. It was regarded as the optimum concentration of the antigen and conjugate. 2. Cut-off value in this IgG ELISA was 0.375 that was determined by mean absorbance (at 492nm) of IFA negative serum added with the dauble value of the standard deviation $(mean{\pm}2S.D.)$. 3. Serum ELISA IgG antibodies to T gondii in the exyerimentally infected dogs were detected firstly at the Week 3 after inoculation and the highest titer was recognized at the Week 4, 5 and 6 after inoculation. 4. Stability of the antigen absorbed in the microplates that were preserved at $4^{\circ}C$ and $-25^{\circ}C$ separately were prolonged up to 3 weeks and 10 weeks at $4^{\circ}C$ and $-25^{\circ}C$, respectively. However the reproducibility was not reliable after the preservation of 4 weeks and longer. 5. Positive rate of the specific antibodies in 312 test sera was 28.5% and there was no significant differences between the male (27.8%) and female (29.5%), respectively. 6. The IgG ELISA was proved to be a specific procedure for the detection of antibodies to canine toxoplasma infection and also evaluated as a screening test for the large scale of test samples in laboratory.

• 천문학회보
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• 제39권1호
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• pp.68.1-68.1
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• 2014

We present the results of far-ultraviolet (FUV) observations of comet C/2001 Q4 (NEAT) obtained with Far-ultraviolet Imaging Spectrograph (FIMS) on board the Korean microsatellite STSAT-1, which operated at an altitude of 700 km in a sun-synchronous orbit. FIMS is a dual channel imaging spectrograph (S-channel 900-1150 ${\AA}$, L-channel 1350-1710 ${\AA}$, and ${\lambda}/{\Delta}{\lambda}$ ~ 550 for both channels) with large image fields of view (S-channel $4.0^{\circ}{\times}4.6^{\prime}$, L-channel $7.5^{\circ}{\times}4.3^{\prime}$, and angular resolution ~ $5-10^{\prime}$) optimized for the observation of diffuse emission of astrophysical radiation. Comet C/2001 Q4 (NEAT) were made in two campaigns during its perihelion approach between May 8 and 15, 2004. Based on the scanning mode observations in the wavelength band of 1400-1700 ${\AA}$, we have constructed an image of the comet with an angular size of $5^{\circ}{\times}5^{\circ}$, which corresponds to the central coma region. Several important fluorescence emission lines were detected including S I multiplets at 1429 and 1479 ${\AA}$, C I multiplets at 1561 and 1657 ${\AA}$, and the CO $A^1{\Pi}-X^1{\Sigma}^+$ Fourth Positive system; we have estimated the production rates of the corresponding species from the fluxes of these emission lines. The estimated production rate of CO was $Q_{CO}=(2.65{\pm}0.63){\times}10^{28}s^{-1}$, which is 6.2-7.4% of the water production rate and is consistent with earlier predictions. The average carbon production rate was estimated to be $Q_C={\sim}1.59{\times}10^{28}s^{-1}$, which is ~60% of the CO production rate. However, the observed carbon profile was steeper than that predicted using the two-component Haser model in the inner coma region, while it was consistent with the model in the outer region. The average sulfur production rate was $Q_S=(4.03{\pm}1.03){\times}10^{27}s^{-1}$, which corresponds to ~1% of the water production rate.

• 해양환경안전학회지
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• 제25권2호
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• pp.201-211
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• 2019

선박의 안전과 보안의 유지는 공급망의 각 단계에서 화물운송 및 여객의 인명 안전을 보장하는데 중추적인 역할을 한다. ISPS Code는 선원과 선박을 보안 위협으로부터 보호하기 위해 SOLAS 협약에 채택되었고, STCW 2010 마닐라 개정에 따라 선원은 반드시 보안 교육을 이수해야 한다. 효과적인 선원의 교육과 훈련은 선박의 보안 관련한 위험을 최소화하기 위한 적절한 이행활동의 수준을 보장하는데 중요하다. 이 연구의 목적은 선원들이 이수한 보안교육과 선원의 보안인식 및 선박의 보안성과 사이의 관계를 실증 분석하는데 있다. 연구 결과에 따르면 (1) 선박 보안 교육을 이수한 선원들은 선박 보안에 대한 인식이 높고 (2) 이러한 보안 교육 및 보안 인식은 선박의 보안성과에 긍정적 영향을 미치며, (3) 보안 인식은 보안 교육과 보안성과 관계에서 매개 효과가 있는 것으로 분석되었다. 따라서 보안 교육과 훈련은 선원의 보안인식과 보안성과에 중요한 영향을 미치며, 이는 결과적으로 해운산업에서 보다 경제적 운영적 및 이미지 측면에서 주요 이점으로 해석될 수 있을 것이다.

• 한국안전학회지
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• 제35권5호
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• pp.49-58
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• 2020

In domestic construction sites, when installing steel pipe scaffolding and system scaffolding, the guardrails are installed after the installation of the work platforms. This conventional guardrail system (CGS) is always exposed to the risk of falls because the safety railing is installed later. In order to prevent fall disasters during erecting and dismantling scaffolds, it is necessary to introduce the advanced guardrail system (AGS) which installs railings in advance of climbing onto a work platform. For the introduction of the AGS, the structural performance of the system scaffolding applying the CGS and the AGS was compared and evaluated. The structural analysis of the system scaffold (height: 31 m and width: 27.4 m) with AGS confirmed that structural safety was ensured because the maximum stress of each element of the system scaffolding satisfies the allowable stress of each element. As a result of performance comparison of CGS and AGS for each element, the combined stress ratio of vertical posts in AGS was 6.4% lower than that of CGS. In addition, in the case of ledger and transom, the combined stress ratios of AGS and CGS were almost the same. The compression test of the assembled system scaffolding (three-storied, 1 bay) showed that the AGS had better performance than the CGS by 9.7% (8.91 kN). The cross bracing exceeds the limit on slenderness ratio of codes for structural steel design. But the safety factor for the compressive load of the cross bracing was evaluated as meeting the design criteria by securing 3 or more. In actual experiments, it was confirmed that brace buckling did not occur even though the overall scaffold was buckled. Therefore, in the case of temporary structures, it was proposed to revise the standards for limiting on slenderness ratio of secondary or auxiliary elements to recommendations. This study can be used as basic data for the introduction of AGS for installing guardrails in advance at domestic construction sites.

• 대한한의학회지
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• 제40권3호
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• pp.59-75
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• 2019

Objectives: The purpose of this study is to examine the current status of Korean medicine health technology assessment and explore realistic plans to activate it. Methods: We investigated all the applications for new health technology assessment related to Korean medicine from 2007 to 2016. The several expert meetings were held to draw out the barriers and improvement strategies of the new health technology assessment of Korean medicine field. Results: There were 31 cases in total except for duplications or reapplies falling into 3 main types. First, 19 of them were to try to enter a medical market and be covered by National Health Insurance. Eight cases were to apply western medicine technology as new health technology in Korean medicine area. The rest was 4 cases, which were totally not appropriate for the purpose of new health technology assessment system. According to the expert opinion, the obstacles of activation in new health technology assessment of Korean medicine were application of unstandardized technology, lack of understanding and experience, lack of clinical trial supporting system for Korean medicine, lack of committee members within the nHTA(new Health Technology Assessment) review board, ambiguous definition of medical practice and sharp conflict between western medicine and Korean medicine. Conclusions: Several suggestions were derived. First of all, to activate Korean medicine in the nHTA system, the existing system should be used sufficiently, and multifaceted efforts are needed to upgrade the system, if necessary. Also, self-help efforts, Korean medicine clinical trial supporting system and increasing R&D investment, establishing extra-committee for Korean medicine in nHTA could be needed. Finally, long-term strategy for improving collaboration between Korean medicine and western medicine should be considered.