Electrical quadruple hysteresis in Pd-doped vanadium pentoxide nanowires due to water adsorption

Kim, Byung Hoon,Oh, Soon-Young,Yu, Han Young,Hong, Won G,Yun, Yong Ju,Kim, Yark Yeon,Kim, Hae Jin Elsevier 2010 SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS Vol.11 No.6

<P>Humidity-dependent current–voltage (<I>I–V</I>) characteristics of Pd-doped vanadium pentoxide nanowires (Pd-VONs) were investigated. Electrical quadruple hysteresis (QH) was observed and attributed to the large amount of water molecules adsorbed on the nanowires. Using QH in Pd-VONs, the reaction of water with PdO was interpreted as the water molecules are desorbed and then dissociated with increasing bias voltage. Owing to the dissociated H<SUP>+</SUP> and OH<SUP>−</SUP> ions, PdO is reduced and oxidized. As a result, water molecules recombine as the bias voltage is decreased.</P>

Superconducting MgB2 Wire Drawing Considering Anisotropic Hardening Behavior and Hydrostatic Effect

Young‑Seok Oh,Ho Won Lee,Kook‑Chae Chung,Duck‑Young Hwang,Seong‑Hoon Kang,Jeong Whan Yoon 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

Numerical modeling was conducted to investigate the deformation behavior of powder mixture during multi-pass drawingprocesses for multi-filamentary MgB2wire. A modified Drucker-Prager Cap (DPC) model with an elliptical cap surface usingthe new material characterization method was developed to capture the anisotropic hardening behavior and hydrostatic effectof the powder mixture. A number of uniaxial die compaction, cold isostatic pressing, diametrical compression, and uniaxialcompression tests were conducted using different powder densities to characterize the modified DPC model. A commercialfinite element software ABAQUS with a user subroutine was used to simulate the drawing of the MgB2wire. The densityand area fraction of the powder mixture during the wire-drawing process were verified with experimental results. The differencein packing density at the inner and outer filaments of the MgB2wire was successfully captured by simulation. Inaddition, the effect of the initial packing density on the superconducting properties of MgB2wire was numerically studied. It is shown that the increase in the superconducting area, which results from a high initial packing density, should be moreeffective compared to the increase in the grain connectivity in enhancing the critical current properties for the MgB2wirewhen the final packing density is saturated after a number of drawing processes.

고속 승산기 알고리즘에 관한 연구

이훈재,오주환 경운대학교 산업기술연구소 2001 産業技術硏究論文誌 Vol.3 No.2(B)

Public-key cryptosystems carry out the modular exponentiation of large integer for security, and modular exponentiation is presented by the serial of the modular multiplication. This thesis presents the classical multiplication method, Montgomery algorithm, Yang algorithm to implement high-speed multiplication above 512-bit.]

20대 연령의 안정성 한계(Limits of Stability)에 대한 연구

권오윤,장정훈 원광보건전문대 1995 원광보건전문대학논문집 Vol.18 No.-

대장내시경 검사 부도관리를 위한 개선활동

권오련,이정선,나은심,김훈 한국의료QA학회 2009 한국의료질향상학회지 Vol.15 No.1

문제: 소화기병검사실에서 대장내시경 검사의 부도건수가 최근 월 200명 정도로 예약인원의 16%에 달한다. 이는 본원 외래진료 부도율이 평균 10%인 것과 비교할 때 상당히 높은 결과이므로 대장내시경 예약환자를 대상으로 부도율 관리를 위한 활동이 필요하였다. 목적: 외래 및 입원환자의 부도건수 및 부도환자의 특성을 분석하고, 개선활동을 통하여 대장내시경 검사의 부도율을 줄인다. 의료기관: 서울 아산병원 질 향상 활동: 부도관리를 위한 개선활동으로 SMS 횟수를 2주전, 4일전, 1일전 3회로 변경하고, 내용도 각 시기마다 차별화하였다. 대장내시경 검사 예약을 하고 기다리는 환자를 대상으로 처방일 순, 예약 날짜순서 등 필요한 항목 순으로 볼 수 있는 리스트가 필요하여 예약대기 프로그램을 개발하였고, 처방일로부터 2주 이내 자동예약을 금지하였다.(7월 10일부터 시작) 예약대기명단에 있는 환자를 대상으로 전화로 예약 변경을 하여 2주 이내에는 예약의 빈자리가 없도록 하였다. 미리 부도를 예측하여 추가로 예약하던 방법에서 정원조정을 하여 정원 외 추가 예약을 하지 않았다. 입원환자 일정관리를 위하여 일정관리 프로그램을 개발하여 타과의뢰 회신을 하는 전임의가 직접 날짜를 전산에 입력하여 회신과 동시에 검사실, 담당주치의, 담당 간호사가 모두 일정을 확인할 수 있도록 하였으나 프로그램이 늦어져 9월 12일부터 시행하였다. 개선효과: 부도건수가 개선 전 8주 동안 385건(예약인원 대비 16%) 에서 개선 후 6주의 평가기간 동안 256건(예약인원대비 14.1%)으로 129건이 감소하였으며, 검사 1-2일전 일정 변경 연락 환자 감소 및 검사 비용 수납 환자의 부도건수가 감소하였다. 대장내시경 검사 예약대기 프로그램 운영 및 예약 변경 전화 활동으로 2달씩 기다리던 환자의 예약일을 약 한 달 정도 단축하여 줄 수 있었다. 검사 정원 관리의 결과로 검사 예약 시 예약기준이 명확해지고, 부적절한 예약으로 인한 검사지연 등이 확실히 줄었다. 또한 입원환자 일정관리 프로그램 적용으로 입원환자의 검사일정과 관련된 전화업무는 확실히 줄어들 것으로 예상된다.

T1급 고속 암호 시스템에 관한 연구

이훈재,류명춘,오주환 경운대학교 산업기술연구소 1998 産業技術硏究論文誌 Vol.1 No.1(A)

In this paper we propose a secure T1-rate digital image conference system which consists a stream cipher of 7-bit real adder with 2 bit carrys and a fast and stable 2-step full-duplex synchronization. And we analyze the cipher algorithm and the synchronization performance of the system.

중성 운반체 선택성 막전극법에 의한 우라늄 금속의 연속정량

정오진,정경훈,김삼혁 조선대학교 환경연구소 1998 環境硏究 Vol.14 No.1

The equipments with which selective ions were able to determinated by ion selective membrane electrode method have been designed with the simole electronic circuits. Having made the selective neutral carrier membrance electrodes with PVC matrix, the response potentials of 〔UO^2+_2〕 were measured with the selective membrance electrode and all of equipments and treatment of data amalysis were operated, and obtained by using the personal computer programs. The neutral carrier membrane electrodes were made by mixing the neutral carriers (macrocyclic compounds and Cryptand), plasticizer(Aliquart 336, TOPO, and TBP) and matrix(PVC). These neutral carrier membrane electrodes showed a linear potential response to the activities of UO^2+_2)(10-2-10-6M). The neutral carrier selective membrane electrodes for UO^2+_2 and equipment for analysis of selective ions mentioned above were stable and reproducible for a long time use, and the selective coefficients for 〔UO^2+_2〕 were increased in proportion to the formation constants of metal complexes with neutral carrier ligands.

중성 운반체 선택성 막전극법에 의한 우라늄 금속의 연속정량

정오진,정경훈,김삼혁 조선대학교 환경공해연구소 1998 環境公害硏究 Vol.14 No.-

The equipments with which selective ions were able to determinated by ion selective membrane electrode method have been designed with the simole electronic circuits. Having made the selective neutral carrier membrance electrodes with PVC matrix. the response potentials of ??O^(2+)_(2)??were measured with the selective membrance electrodes and all of equipments and treatment of data amalysis were operated, and obtained by using the personal computer programs. The neutral carrier membrane electrodes were made by mixing the neutral carriers (macrocyclic compounds and Cryptand), p1asticizer(A1iquart 336, TOPO, and TBP) and matrix(PVC). These neutral carrier membrane electrodes showed a linear potential response to the activities of UO^(2+)_(2)(10-2-10-6M). The neutral carrier selective membrane electrodes for UO^(2+)_(2) and equipment for analysis of selective ions mentioned above were stable and reproducible for a long time use, and the selective coefficients for ??O^(2+)_(2)??were increased in proportion to the formation constants of metal complexes with neutral carrier ligands.

폐탄광 주변 하천의 수질조사

정경훈,최형일,정오진,정재경,강성환,조영찬 조선대학교 환경연구소 1998 環境硏究 Vol.14 No.1

The Water quality for river surrounding closed coal mine in Hwasun area Chunnam was investigated. The investigated factors were pH, turbidity, conductivity, Fe, SO_^-2, Ca, and Mg concentration, and the crystallization form and components of suspended solids were also investigated by scanning electron microscope and energy dispersion system. Extremely high value of turbidity and conductivity were represented in Honam Kwangup (N-7) and Honam Tanza (N-3)area, respectively. Fe concentration was lower in all sampling sites, and the concentration of SO_4^-2 ion was higher than 200㎎/L in all sampling sites excepting Dongyang Tanggwang area (N-2) and Hwail wetland (N-11). The SEM micrograph and EDS analysis showed that the crystallization form of the suspended solids was formless, These particles have size of less than 10㎛ and the main components was O, Al, Fe and S. The corelation values between conductivity and Mg, SO_4^-2, and Ca were 0.967, 0.959, 0.931, respectively, and the results indicate good corelation.

고속치환 영상처리를 위한 암호화 기법에 관한 연구

윤정오,이훈재,홍영호,최병진 경운대학교 산업기술연구소 1998 産業技術硏究論文誌 Vol.1 No.1(A)

In this paper, we suggest a new encryption system for high speed permutation image processing. We show how to secure attack relative to redundancy in image data. In addition, by applying the proposed permutation algorithm in image data, we show how to solve problems related to scanning sequence and scraming.