• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.1956-1964
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• 2014

To provide the scientific corroboration of the traditional uses of Akebia quinata (Thunb.) Decne., a detailed analytical examination of A. quinata stems was carried out using a reversed-phase high performance liquid chromatography (RP-HPLC) method coupled to photodiode array detector (PDA) for the simultaneous determination of four phenolic substances; cuneataside D (1), 2-(3,4-dihydroxyphenyl)ethyl-O-${\beta}$-D-glucopyranoside (2), 3-caffeoylquinic acid (3) and calceolarioside B (4). Particular attention was focused on the main compound, 3-caffeoylquinic acid (3), which has a range of biological functions. In addition, 2-(3,4-dihydroxyphenyl)ethyl-O-${\beta}$-D-glucopyranoside (2) was considered as a discernible marker of A. quinata from its easy confuse plants. The contents of compounds 2 and 3 ranged from 0.72 to 2.68 mg/g and from 1.66 to 5.64 mg/g, respectively. The validation data indicated that this HPLC/PDA assay was used successfully to quantify the four phenolic compounds in A. quinata from different locations using relatively simple conditions and procedures. The pattern-recognition analysis data from 53 samples classified them into two groups, allowing discrimination between A. quinata and comparable herbs. The results suggest that the established HPLC/PDA method is suitable for quantitation and pattern-recognition analyses for a quality evaluation of this medicinal herb.

• 한국ITS학회 논문지
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• 제4권2호
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• pp.33-43
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• 2005

기존 교통시스템의 운영 효율을 증진시키고 교통시설과 교통안전, 교통환경 개선을 동시에 충족시키는 지능형교통체계(ITS)도입을 위해 '99.2월에 교통체계효율화법을 제정하여 제도적 차원에서의 기반확대를 조성하였고, 지난 2000년 10월 대전광역시, 전주시, 제주시를 첨단교통모델도시로 선정하여 ITS 전국확산을 위한 교두보를 마련하였다. 국내에서 처음 시도된 첨단교통모델도시는 ITS의 수준을 한 단계 올렸고, 이를 통해 많은 관련 전문 인력의 양성과 경험이 축적이 된것으로 평가하고 있다. 따라서 지능형교통체계(ITS)와 관련하여 우리나라 3개 도시(대전광역시, 전주시, 제주시)에서 진행했던 지능형교통체계 구축사업의 특징과 추진과정 중의 시행착오 등을 파악하여 향후 국가ITS사업의 시사점을 도출하고자 한다. 총괄사업보고서 및 백서, 기본설계, 입찰안내서, 실시설계도서, 관리기관의 최종보고서 등을 분석하여 ITS사업의 기획에서 그 사업의 평가까지 일련의 단계를 통해 문제점과 향후 지자체 지능형교통체계사업의 발전방안을 논의하였다. 특히, 사업기간, 시스템 구성, 추진조직, 운영체계, 민간투자 및 평가체계와 함께 사업관리 등 발주방식에 대한 논의하였다.

• 대한인간공학회지
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• 제35권2호
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• pp.85-95
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• 2016

Objective:The purpose of this study is to suggest the methodology for establishment of safety culture in industry. Background: There have been studies indicating positive relation between safety culture and safety performance. But the areas of those efforts have been mainly focused on elements or factors consisting of safety culture. So it is expected that studies on methodologies for developing process of the culture could contribute for the industry to understand and apply it accordingly in order to improve their practices. Method: In this study, the scope was considered just for industry, even though there are many fields of culture. As the first step, the limitations of regulatory control and efforts by industry were reviewed, and the trends of researches were presented. In the second step, the global company practices were provided with detailed activities. Results: This paper showed the limitations of present state in government strategies and industry for safety culture improvement. Also the restricted areas in researches were shown. As one of the solutions to resolve those things, such global company practices as perception to safety journey, the steps of culture development, total safety philosophy, structure and elements of safety process, standards and procedures, training, and up to keys to success were suggested. Conclusion: Through this study, the development of the structure of safety process which consists of many purposeful activities has been derived to be very important. Because it will be the seeds of safety culture expressing their thinking process and behaviors. Also it is required to approach success step by step according to the achievement of each step. Application: This study can be used to develop the methodology and safety process in industry with different viewpoints for safety culture establishment.

• Structural Engineering and Mechanics
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• 제90권3호
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• pp.253-261
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• 2024

This research explores a new finite element model for the free vibration analysis of bi-directional functionally graded (BDFG) beams. The model is based on an efficient higher-order shear deformation beam theory that incorporates a trigonometric warping function for both transverse shear deformation and stress to guarantee traction-free boundary conditions without the necessity of shear correction factors. The proposed two-node beam element has three degrees of freedom per node, and the inter-element continuity is retained using both C1 and C0 continuities for kinematics variables. In addition, the mechanical properties of the (BDFG) beam vary gradually and smoothly in both the in-plane and out-of-plane beam's directions according to an exponential power-law distribution. The highly elevated performance of the developed model is shown by comparing it to conceptual frameworks and solution procedures. Detailed numerical investigations are also conducted to examine the impact of boundary conditions, the bi-directional gradient indices, and the slenderness ratio on the free vibration response of BDFG beams. The suggested finite element beam model is an excellent potential tool for the design and the mechanical behavior estimation of BDFG structures.

• 한국음향학회지
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• 제43권3호
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• pp.293-304
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• 2024

본 논문에서는 선체고정형소나의 해상 시운전을 효율적이면서 신뢰성 있게 수행하기 위한 방안을 제시하였다. 현재 함 건조 과정에서 선체고정형소나의 해상 시운전 절차에는 해저 지형, 계절적 요인 등에 따른 탐지 성능의 변동성이 세밀하게 반영되어 있지 않다. 문제 해결을 위해 1967년부터 2022년까지의 기간 동안 Array for Real time Geostrophic Oceanography(ARGO) 플로트 및 정선 해양관측 정점 데이터를 통해 수온, 염도 구조를 수집하고, 수집 된 데이터를 바탕으로 월별 평균 음속 구조를 분석하였다. Bellhop 모델링을 통해 해상 시운전 구역 내 해저 지형 선택, 선체고정형소나와 표적함의 배치, 음파 전송 방향 및 빔 조향각 설정이 포함된 해상 시운전 세부 수행 방안을 제안하였다. 또한, 획득 데이터를 활용하여 물리정보신경망이 적용된 기계학습 모델을 도출하였다. 이를 통해 해상 시운전 구역내 특정 지점에서 해상 시운전을 수행하는 시점의 계절적 요소를 반영한 음속 구조를 예측하고, Bellhop 모델링 결과를 통해 계절적 요인에 의한 탐지 성능 변동성을 반영한 해상 시운전 방안을 제시하였다.

• 대한공간정보학회지
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• 제21권4호
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• pp.143-150
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• 2013

본 연구의 목적은 상세 레벨의 대규모 도로망 데이터를 대상으로 다양한 축척과 추상화 수준을 가진 상위 레벨의 소축척 도로 선형 사상을 유도하는 가변-축척 기반 네트워크 데이터의 생성 방안을 제시하는 것이다. 이를 위해 우선, 가변-축척 모델 구축을 위해 관련 용어의 정의와 모델 구축시의 이점과 구축 절차에 대해 살펴보았다. 둘째, 가변-축척 모델을 설계하기 위해 지도 표출을 위한 표현 레벨과 레이어 구성요소를 제시하였다. 또한 상위 LoD와 데이터 연계 방법과 인덱스 구조 생성을 위한 규칙을 정의 하였다. 마지막으로 설계된 모델의 구현과 검증을 위해 제시된 알고리즘을 실제적인 연구지역 도로망(제주도)에 적용하여 가변 축척 도로망을 유도하여 구축하고, 공간 데이터베이스(Oracle Spatial)에 저장한 후 성능 분석을 통해 모델의 효율성과 타당성을 검증하였다.

• Journal of Korean Neurosurgical Society
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• 제49권5호
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• pp.257-261
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• 2011

Objective : Successful coil embolization of anterior communicating (A-com) artery aneurysms requires good visualization and understanding of the entire H complex. Bilateral carotid angiography may optimize anatomical understanding and visualization of the H complex. We therefore assessed the efficacy of simultaneous bilateral internal carotid angiography during coil embolization for A-com artery aneurysms. Methods : Of the 153 patients with intracranial saccular aneurysms who underwent embolization between July 2008 and December 2009, 12 had A-com artery aneurysms and were embolized under bilateral carotid angiography. Patients were evaluated angiographically, immediately and 6 months (n=11) after embolization, using a 3-point scale (complete, residual neck, residual aneurysm). The safety, performance and efficacy of this approach were retrospectively evaluated. Results: In all patients, bilateral internal carotid artery angiography provided more detailed anatomical information and understanding around the A-com artery, and, in complex situations, it allowed for more effective coil embolization through bilateral routes to the A-com artery. Angiography immediately after embolization showed occlusion of 11 of the 12 (92%) aneurysms, with none of these 11 showing evidence of recanalization at 6 months. Conclusion : These findings indicate that simultaneous bilateral carotid angiography during coil embolization of selected complex A-com artery aneurysms provided improved anatomical understanding, and resulted in more effective and safer procedures than typical unilateral angiography.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.784-793
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• 2006

As the number of CFRD constructions increases, the necessity of an accurate assessment on its behavior also has been increasing accordingly. The performance of concrete faced rockfill dam (CFRD) under different water levels is greatly concerned by dam engineers and designers in the world. However, domestic research on CFRD design and construction has yet been insignificant. This study deals with three centrifuge model tests, mainly investigates the deformation of the concrete faced slabs with different face slab stiffness under different water levels. The prototype of a centrifugal model dam is half size of domestic CFRD dam. Detailed material preparation, model design, model set-up, model instrumentation and testing procedures are presented. In order to simulate the prototype concrete faced slab, three kinds of thin fiberglass plates with different thickness was adopted in the three model tests. The water level control facility was specially designed for this experiment to control the water level rise and drawdown during centrifuge flight. Although most of the results from the three model tests are satisfactory, it is also required that the centrifuge test results should be compared with those of numerical analysis and field measurements to analyze the centrifuge test results more in detail.

• Journal of Communications and Networks
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• 제2권1호
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• pp.5-17
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• 2000

cdma2000 offers several enhancement as compared to TIA/EIA-95, although it remains fully compatible with TIA/EIA-95 systems and allows for a smooth migration from one to the other-Major new capability include:1)connectivity to GSM-MAP in addition to IP and IS-41 networks; 2) new layering with new LAC and MAC architectures for improved service multiplexing and QoS management and efficient use of radio resource ;3) new bands and band widths of operation in support of various operator need and constraints, as well as desire for a smooth and progressive migration to cdma 2000; and 4) flexible channel structure in support of multiple services with various QoS and variable transmission rates at up to 1 Mbps per channel and 2 Mbps per user. Given the phenomenal success of wireless services and desire for higher rate wireless services. improved spectrum efficiency was a major design goal in the elaboration of cdma2000. Major capacity enhancing features include; 1) turbo coding for data transmission: 2)fast forward link power control :3) forward link transmit diversity; 4) support of directive antenna transmission techniques; 5) coherent reverse link structure; and 6) enhanced access channel operation. As users increasingly rely on their cell phone at work and at home for voice and data exchange, the stand-by time and operation-time are essential parameters that can influence customer's satisfaction and service utilization. Another major goal of cdma2000 was therefore to enable manufacturers to further optimize power utilization in the terminal. Major battery life enhancing features include; 1) improved reverse link performance (i.e., reduced transmit power per information bit; 2) new common channel structure and operation ;3) quick paging channel operation; 4) reverse link gated transmission ; and 5) new MAC stated for efficient and ubiquitous idle time idle time operation. this article provides additional details on those enhancements. The intent is not to duplicate the detailed cdma2000 radio access network specification, but rather to provide some background on the new features of cdma2000 and on the qualitative improvements as compared to the TIA/EIA-95 based systems. The article is focused on the physical layer structure and associated procedures. It therefore does not cover the MAC, LAC, radio resource management [1], or any other signaling protocols in any detail. We assume some familiarity with the basic CDMA concepts used in TIA/EIA-95.

• Corrosion Science and Technology
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• 제14권5호
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• pp.213-217
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• 2015

Recently, household electronic industries require environmentally-friendly and highly functional steels in order to enhance the quality of human life. Customers especially require both excellent corrosion and abrasion resistant anti-fingerprint steels for digital TV panels. Thus POSCO has developed new functional electro-galvanized steels, which have double coated layers with organic-inorganic composites on the zinc surface of the steel for usage as the bottom chassis panel of TVs. The inorganic solution for the bottom layer consists of inorganic phosphate, magnesium, and zirconium compounds with a small amount of epoxy binder, and affords both improved adhesion properties by chemical conversion reactions and corrosion resistance due to a self-healing effect. The composite solution for the top layer was prepared by fine dispersion of organic-inorganic ingredients that consist of a urethane modified polyacrylate polymer, hardener, silica sol and a titanium complex inhibitor in aqueous media. Both composite solutions were coated on the steel surface by using a roll coater and then cured through an induction furnace in the electro-galvanizing line. New anti-fingerprint steel was evaluated for quality performance through such procedures as the salt spray test for corrosion resistance, tribological test for abrasion resistance, and conductivity test for surface electric conductance regarding to both types of polymer resin and coating weight of composite solution. New composite coated anti-fingerprint steels afford both better corrosion resistance and abrasion properties compared to conventional anti-fingerprint steel that mainly consists of acrylate polymers. Detailed discussions of both composite solutions and experimental results suggest that urethane modifications of acrylate polymers of composite solutions play a key role in enhanced quality performances.