• 제목/요약/키워드: e-type order

검색결과 1,149건 처리시간 0.037초

$TiO_{2}$ 단결정의 비선형광학 특성 (Nonlinear optical properties of $TiO_{2}$ single crystal)

  • 신재혁;오근호
    • 한국결정성장학회지
    • /
    • 제5권3호
    • /
    • pp.240-249
    • /
    • 1995
  • 무색투명하고 순수한 단결정을 얻기 위하여 $TiO_{2}$(rutile) 단결정을 floating zone법으로 성장하였다. 성장된 결정을 c축에 수직 및 수평하게 절단하여 500~1000 nm 범위의 파장에서 선형 굴절율을 측정하였으며 흡수스펙트롬으로부터 optical energy band gap이 2.99 eV임을 알 수 있었다. $TiO_{2}$(rutile) 단결정의 $\chi^{(3)}$ 값을 반경험적인 모델을 기반으로 하여 $SiO_{2}$ quartz 단결정의 $\chi^{(3)}$ 값과 비교하여 분석하였다. 또한 제 3 비선형광학 특성에 있어서의 Ti$\^{4+}$의 영향을 해석하기 위해 second hyperpolarizability, ${\gamma}$(Ti$\^{4+}$)를 계산하였다.

  • PDF

耳鳴의 形態와 治療效率에 對한 臨床的 分析 (A Clinical analysis on the Treatment efficiency of Tinnitus by Types of bianzheng(辨證))

  • 김경준
    • 한방안이비인후피부과학회지
    • /
    • 제12권2호
    • /
    • pp.182-188
    • /
    • 1999
  • Tinnitus is a symptom frequently encountered in the E.N.T. clinic and variously described as buzzing, ringing and thumping sound, etc., but the cause, pathogenesis, specific treatment remains to be established through close investigation. In fact, it is not easy to evaluate the treatment efficiency of tinnitus reasonably. However, in this study. we clinically investigated 47 patients who visited E.N.T. department of Kyung Won University Hospital from May. 1996 to May. 1999 and belonged to specific bianzheng(辨證) types of tinnitus classified by bianzheng(辨證), a kind of diagnostic method in order to estimate efficiency of the treatment and give aids to establishing more effective and recognizable treatment method. The result is as follows: 1) In bianzheng(辨證) types of tinnitus, Piweixuruo(脾胃虛弱) was most frequently found, in descending order, Shenjingkuisun(腎精虧損), Ganhuoshangra(肝火上擾), Tanhuoyongjie(痰火壅結). 2) In the treatment efficiency, the type of Piweixuruo(脾胃虛弱) showed the highest, in descending order, Ganhuoshangrao(肝火上擾), Tanhuoyongjie(痰火壅結) and Shenjingkuisun(腎精虧損). 3) The treatment efficiency is shown higher in patients with tinnitus included in other sysmptoms than those with a simple symptom of tinnitus. especially in case of tinnitus accompanied by vertigo, we could get much higher treatment efficiency more than we had expected.

  • PDF

The Relationship between MRO E-Commerce System and Purchase Effects

  • Kwon, Soon-Won;Kim, Young-Ei;Youn, Myoung-Kil;Jeon, Ta-Sik
    • 유통과학연구
    • /
    • 제8권3호
    • /
    • pp.5-15
    • /
    • 2010
  • Business corporations have become specialized and on the basis of various interests try to strengthen their competitiveness through a cooperative system of purchase, distribution, service and IT technology. And an advanced Internet-based electronic commerce has witnessed explosive growth and a business-to-business (B2B) electronic commerce. Through E-marketplace. business corporations achieve such diverse utilities as expenditure curtailment, process reduction and prime cost reduction. And with business depression worldwide and soaring prices of materials, many business corporations consider the introduction of comprehensive purchase of MRO (maintenance, repair and operation) materials. The Purpose of this study was to examine the definition of B2B E-marketplace and the utilities of MRO commerce correctly focusing on an empirical analysis of cases of MRO supply and purchase business corporations. The indications acquired from this research results are as follows. Firstly, as for MRO integrated purchase under the characteristics of the market environment, it had to use the supplier obligatorily through the integrated purchase on the level of CEO's decision-making or the group rather than the voluntary will of the purchasing department or the procurement department. Secondly, as for the present B2B E-marketplace MRO purchase, the purchasing agency business has formed the mainstream, but it is aiming at the diversification of the benefit by supplementing/correcting the business model such as category type, mediation business type, MRO-type advancing in the store inclusive of the purchasing agency business, keeping pace with the potential market of MRO. Thirdly, as for analysis of the products, the purchaser wants more various products and assortment of goods than those of the present time, and also to be provided with the precise product information. Especially, as the importance of the product sourcing becomes high, the whole energy has been bestowed on acquirement of the excellent suppliers. Fourth, as for use of B2B E-marketplace MRO integrated purchasing system, there are the purchasing companies complaining the inconvenience even until now, and there is the demerit spending the long time during the image move and the process treatment. It shall try to shorten the searching time and the process treatment time as the system is centered on the purchaser. In order to enhance the efficiency of MRO E-marketplace purchase, followings must be considered: First, because the importance of product sources ever increases, an excellent supplier must be secured earnestly. Second, the time of process must be reduced focusing on purchasers. B2B E-marketplace will increase and diversify electronic commerce continuously. Through MRO E-marketplace, business corporations will reduce expenditure, achieve a transparent and speedy trade, and purchase products of fine quality, thus establishing a most effective market. In addition, in this study the investigator brings focus into MRO which has not been clearly discussed in the academic and business world so far and intensively highlights an indirect material-oriented expenditure curtailment effect. By taking all the aspects of supplier, purchaser and practical economical value into account, the investigator presents a strategic direction for the successful comprehensive purchase of B2B MRO.

  • PDF

Ground Coupling 구조를 이용한 초소형 Metamaterial Bluetooth 칩 안테나 (A Compact Metamaterial Chip Antenna with Ground Coupling Structure for Bluetooth Application)

  • 박영환;이강희;지정근;류지웅;김기호;성원모
    • 한국전자파학회논문지
    • /
    • 제20권9호
    • /
    • pp.930-935
    • /
    • 2009
  • 본 논문은 이동 통신용 단말기에 적용할 수 있는 초소형 metamaterial BT(Bluetooth) 칩 안테나에 대해 기술하였다. 제안된 안테나 크기는 $3.0\;mm(W){\times}2.0\;mm(L){\times}1.2\;mm(H)$이며, SMD(Surface Mount Device) 가능한 칩 형태로 제작되었다. 0차 공진 특성은 surface current scanning system을 이용하여 surface current의 magnitude와 phase 분포를 통해 분석하였다. 제작된 안테나는 전방향성의 방사 패턴을 가지며, 3D 평균 이득 측정 결과 -1.7 dBi 이상의 특성을 가짐을 확인할 수 있었다.

적콜라비 새싹채소 종자에서 분리한 Escherichia coli strain RC-4-D의 생장예측모델 (Mathematical modeling of growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds)

  • 최수연;류상돈;박병용;김세리;김현주;이승돈;김원일
    • 한국식품저장유통학회지
    • /
    • 제24권6호
    • /
    • pp.778-785
    • /
    • 2017
  • 본 연구는 시중 유통되고 있는 새싹채소 재배용 적콜라비 종자에서 분리한 E. coli strain RC-4-D의 생장예측모델을 개발하기 위해 수행되었다. 각 온도조건(10, 15, 20, 25, $30^{\circ}C$) 별로 적콜라비 중 E. coli strain RC-4-D 밀도 변화를 조사하였고 Baranyi model을 1차 생장예측모델로 이용하였고 각 온도별로 최대생장률(${\mu}max$)과 $10^{\circ}C$를 제외한 유도기(LPD) 값을 도출하였다. E. coli strain RC-4-D의 최대생장률에 대한 2차 생장예측모델로써 suboptimal Ratkowsky square-root, suboptimal Huang square-root, suboptimal Arrhenius-type 세 종류의 모델을 비교하였다. 모델 적합성 검정 결과, suboptimal Huang square-root 모델이 정확도가 가장 높고 suboptimal Ratkowsky square-root 모델이 편차가 가장 적은 것으로 나타났다. 종합적으로, RMSE가 0.100, $A_f$가 1.255, $B_f$가 0.999인 suboptimal Ratkowsky square-root 모델이 온도의 영향을 설명하는 가장 적합한 2차 생장예측 모델인 것으로 나타났다. 본 연구에서 개발한 모델은 적콜라비 새싹채소 생산에 있어서 E. coli의 생장을 예측하고 미생물 위해성평가를 수행하는데 활용될 것으로 기대된다.

BaaS를 이용한 하이브리드 블록체인 기반 전자투표 시스템 (A Hybrid Blockchain-Based E-Voting System with BaaS)

  • 강명조;김미희
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
    • /
    • 제12권8호
    • /
    • pp.253-262
    • /
    • 2023
  • 전자투표는 정해진 장소에서의 키오스크 투표, 정해지지 않은 장소에서의 인터넷 투표 등의 행위를 포함한 개념으로, 오프라인 투표 수행 시 많은 자원과 비용이 소모되는 문제를 완화하기 위해 등장했다. 전자투표를 사용하면 투표 및 개표 업무의 효율성 증대, 비용 감소, 투표율 상승, 오류 감소 등 기존 투표시스템에 비해 많은 이점을 가진다. 하지만 중앙집중식 전자투표는 타인에 의한 데이터 위·변조 및 해킹 우려로 투표 결과를 신뢰할 수 없어 공적 선거 및 기업 안건 투표에 주목받지 못했다. 이를 해결하기 위해 최근에는 블록체인 기술을 활용한 전자투표 시스템을 설계하여 투표정보의 신뢰성 증가, 투명성 확보 등 기존의 전자투표에서 부족한 개념을 보완하는 연구가 활발히 진행되어왔다. 본 논문에서는 퍼블릭 블록체인과 프라이빗 블록체인을 융합하여 사용하는 하이브리드 블록체인 기술을 도입한 전자투표 시스템을 제안하였다. 하이브리드 블록체 인은 프라이빗 블록체인을 이용해 느린 트랜잭션 처리 속도와 수수료 문제를 해결하고, 퍼블릭 블록체인을 통해 거래의 투명성과 데이터 무결성 부족 문제를 보완할 수 있다. 또한, 설계한 시스템을 BaaS로 구현하여 블록체인의 타입 변환 용이성 및 확장성을 확보하고 강력한 연산력을 제공할 수 있도록 한다. BaaS란, Blockchain as a Service의 약어로 클라우드 컴퓨팅 기술 중 하나이며 인터넷을 통해 블록체인 플랫폼 및 소프트웨어를 제공하는 서비스를 의미한다. 본 논문에서는 타당성을 평가하기 위해 제안시스템과 국내외에서 진행한 전자투표 관련 연구를 블록체인 타입, 익명성, 검증 프로세스, 스마트 계약, 성능, 확장성 측면에서 비교 분석한다.

Evaluation of the Function exp$(x^2)$ erfc(x) to Higher Precisions for Higher Order Derivative Polarography of CE-type Electrode Process

  • Kim, Myung-Hoon;Smith, Veriti P.;Hong, Tae-Kee
    • Bulletin of the Korean Chemical Society
    • /
    • 제11권6호
    • /
    • pp.497-505
    • /
    • 1990
  • The function exp$(x^2)$erfc(x), which is often encountered in studies of electrode kinetics, is evaluated to an extended precision with 32 significant decimal digits in order to find theoretical relationships used in derivative polarography/voltammetry for a chemically-coupled electrode process. Computations with a lower precision are not successful. Evaluation of the function is accomplished by using three types of expansions for the function. Best ranges of arguments are selected for each equation for particular precisions for efficiencies. The method is successfully applied to calculate higher-order derivatives of the current-potential curves in all potential ranges for a reversible electron transfer reaction coupled with a prior chemical equilibrium (i.e., a CE type process). Various parameters that characterize the peak asymmetry (such as ratios of peak-heights, ratios of half-peak-widths, and separations in peak-potentials) are analyzed to find how kinetic and thermodynamic parameters influence shapes of the derivatives. The results from the CE process is compared with those from an EC process in which a reversible electron transfer is coupled with a follow-up homogeneous chemical reaction. The two processes exibit quite contrasting differences for values of the parameters.

4 K GM 극저온냉동기를 이용한 헬륨 재응축형 극저온용기의 성능 평가시험 (Test of evaluating performance of Helium recondensing type cryostat with 4 K GM cryocooler)

  • 김형진;김성래;심기덕;진홍범;권영길;장호명;이봉근
    • 한국초전도저온공학회:학술대회논문집
    • /
    • 한국초전도저온공학회 2002년도 학술대회 논문집
    • /
    • pp.77-81
    • /
    • 2002
  • The helium recondensing type cryostat with 4 K GM cryocooler is fabricated in order to keep cryogenic state of two saddle type superconducting magnet opposite to each other designed maximum 0.3 T magnetic field, and 1270 mm diameter open bore. The current leads which consist of metal current leads made for brass sheet and HTS current leads made in American Superconductor$^{TM}$ intermediate cool down with cryocooler Thus , the cryocooler for helium recondensing is a 1.5W/4.2 K GM SUMITOMO cryocooler. While superconducting magnet is working of 1600 gauss to 200 A, the cryostat keep constantly the level of liquid helium at 0.05 bar gauge pressure.e.

  • PDF

대형구조물 동특성 실험을 위한 가변 동하중 가진 시스템 개발 (A Development of a Variable Dynamic Force Type Exciter for Modal Test of a Large Structure)

  • 손성완;이홍기;최수현;강동억
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2002년도 추계학술대회논문집
    • /
    • pp.826-831
    • /
    • 2002
  • In order to investigate the dynamic characteristics of real structure, many dynamic engineer had been interested in modal test however it is not easy to perform dynamic test of large structure because of many difficulties such as unsatisfied excitation force in global mode frequency range, measurement of dynamic force and so on. Therefore. new type vibration exciter with variable stiffness support system and dynamic force was developed to provide a improved experimental environment for a large and complex structure. The developed exciter improved from two viewpoint, dynamic performance and utility convenience. its characteristics was shown in this paper.

  • PDF

리니어타잎 초전도 전원장치의 동작특성 (Operating characteristics of linear type magnetic flux pump)

  • 정윤도;배덕권;윤용수;고태국
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2008년도 제39회 하계학술대회
    • /
    • pp.665-666
    • /
    • 2008
  • Inserted HTS (high temperature superconducting) coil is promisingly expected as a solution for achievement of higher fields such as GHz scale NMR magnet. However, HTS magnet causes persistent current decay in the persistent current mode and this decay should be compensated in order to keep stable magnetic field. As a solution for the decay in the HTS magnets, we proposed a new type superconducting power supply, i.e., linear type magnetic flux pump (LTMFP). The LTMFP mainly consists of DC bias coil, 3-phase AC coil and superconducting Nb foil. The compensating current in closed superconductive circuit can be easily controlled by the intensity of 3-phase AC current and its frequency. In this study, it has been investigated that the flux pump can effectively charge the current for various frequencies according to the different load magnets.

  • PDF