순수 Ti 용접재의 기계적 특성 및 피로크랙 성장특성에 관한 연구

최병희,이종범,정장만,장경천,최병기 朝鮮大學校 機械技術硏究所 2007 機械技術硏究 Vol.10 No.2

In this study, fatigue fracture often occurs due to the fatigue crack in the machine and welding structure and this is the result of severe operational environment, operational condition, and design condition caused by the large scaled and light weighted machine and structure in recent days. Therefore, safety and reliability should be secured to prevent the fatigue fracture of machine and structure, and the use of titanium has been increased in the metal material for the safety and reliability. The purpose of this thesis was to investigate the welding characteristics and fatigue crack growth characteristics of titanium, commonly using power station, aircraft and ship. The experimented material was TIG welded in order to look over the characteristics according to the notch position and compare with other material. The results, at the same welding condition, 4 pass specimen which had the smallest number of welding pass had the highest tensile strength with 51kgf/㎟ and the tensile strength of 4 pass specimen was 10% higher than the one of 7 pass specimen, and its elongation reduced about 30%. The initial fatigue crack growth characteristic is slower in this order, boundary zone < welding zone < HAZ < base metal. Especially boundary zone's growth speed is slower about 30 times than base metals.

중국의 WTO 가입이 한ㆍ중 경제에 미치는 효과분석

박희종 명지대학교 경제연구소 2001 경영연구 Vol.20 No.1

우리나라 청정지역에서 측정한 PM_(2.5) 입자의 특성

이종훈,김용표,문길주,김희강,정용승,이종범 江原大學校 附設 環境硏究所 1998 環境硏究 Vol.15 No.-

Atmospheric fine particles (PM_(2.5)) were collected at the background sites, Kangwha, Taean, and Kosan and characterized to understand their behaviors at the sites. Daily samples of PM_(2.5) mass were measured and ionic species, carbonaceous species, and gaseous species were analyzed. Four-daγ backward trajectory analysis was also carried out. The mean concentrations of anthropogenic species were highest at Kangwha among three sites, while contributions from sea salts were highest at Taean during the measurement period due to higher wind speed at Taean. Major chemical components in fine particles were sulfates organic carbon, nitrate, and ammonium. Most of the non-sea-salt (nss) sulfates in PM_(2.5) might be present as ammonium sulfates at these sites. Most air parcels arriving at Kangwha and Taean were from northern China. Therefore, both sites were thought to be affected by the same air parcel. At Kosan, during the measurement period, air parcels were from either northern China or southern China. The nss sulfate concentration in the air parcels from southern China was higher, while the nss calcium nitrate, and ammonium concentrations were higher when the air parcels were from northern China.

韓國의 對美貿易構造分析:1971~1990

朴熙宗 明知大學校 經濟硏究所 1992 경영연구 Vol.8 No.1

순환형 디지탈 필터의 설계와 구성

박상희,김종현 연세대학교 산업기술연구소 1982 논문집 Vol.14 No.1

The digital filter is the time invariant discrete system and has the advantages in accuracy, stability, flexibility and noise immunity. In this paper, digital low-pass filter, high-pass filter and digital differentiator are designed and its hardwares are implemented by using Intel 8085 microprocessor and digital LSI components. The digital butterworth low-pass filter and high-pass filter are designed by means of squared magnitude function and frequency transformation. The digital differentiator is designed by matched z-transformation.

조도 제어용 ASK 및 FSK 전력선 모뎀의 성능 평가

박종연,최현희 강원대학교 정보통신연구소 2008 정보통신논문지 Vol.12 No.-

In this paper, two type of power line modems are evaluated to realize the lamp control system using the power line communication. One is FSK modem using DS/SS and the other is the manchester coded ASK modem. Both modems apply (7,4) hamming code to correct errors. There are two kinds of used loads ; the electronic ballast and the magnetic ballast. The Electronic ballast is for a 250Watt HID lamp, a 50watt florescent lamp and a 50watt induction lamp. The Magnetic ballast is for a 250watt HID lamp. Bit errors are measured between the main modem and the ASK or the FSK sub-modems in loads at equal distances. As a result, it is estimated that the FSK modem is more appropriate than the ASK modem in terms of the lamp dimming system. And we also concluded that the (7,4) hamming code is not suitable for ASK application In the lamp control system.

해석방법에 따른 빌딩구조물의 비탄성 응답 평가

장동휘,송종걸,정영화 江原大學校 産業技術硏究所 2005 産業技術硏究 Vol.25 No.A

Recent earthquakes have shown that near-field earthquakes can produce spectral demands significantly larger than those considered in current design code. International Atomic Energy Agency (IAEA) has recently initiated a coordinated research program on safety significance of near-field earthquakes. The purpose of this program is to focus on the assessment of vulnerability of nuclear facility structures by using and adapting the best available engineering practices appropriate to evaluate the effects of near-field earthquakes. The objective of this paper is to evaluate of seismic responses of a shear building test specimen subjected to near-filed earthquakes. To achieve the objective, the seismic responses of the test specimen, evaluated by the Displacement Coefficient Method (DCM) and Nonlinear Dynamic Analysis (NDA), are compared with those by the experimental tests.

통합 통신망 관리 시스템 구축 방안 연구

이종근,임미경,이광휘,김한경,김태수 國立 昌原大學校 精報通信硏究所 1998 精報通信論文集 Vol.2 No.-

This paper presents a system for internetworking between different network management protocols. The internetworking system between SNMP(Simple Network Management Protocol) and CMIP(Common Management Information Protocol) has been designed. SNMP has been used as a standard protocol in Internet while CMIP has been selected as management protocol in OSI network. This approach is different from previous researches which convert protocols between management protocols. We have newly defined manage objects structure. Thus, even if a new management protocol would be introduce in addition, the new gateway system needs not be designed. We can achieve it through minimum modification in the interface of the managed objects. So, we can support managed objects defined previously using MOVI(Manage Object View Interface) concept presented in our previous research. Through this research, we have some additional benefits: it is able to internetwork between more complicated network management protocols, to increase usefulness of SNMP and CMIP, also it will use in internetworking between new network management protocols.

경구진정 실패 후 피부 도포마취제를 사용한 정주진정으로의 전환 치료

이은희,김승오,김종수,유승훈 大韓小兒齒科學會 2010 大韓小兒齒科學會誌 Vol.37 No.2

Chloral hydrate와 hydroxizine을 이용한 경구진정법은 적용대상의 나이와 체중에 따라 제한을 받는다. 일반적으로 경구 진정법은 36개월 미만, 체중 15 kg 미만의 환아에서 가장 좋은 진정 효과를 보인다. 그러나 36개월 이상 또는 15 kg 이상의 환아에 대해서는 경구진정법이 적절한 진정 효과를 얻는데 한계를 가지며, 얕은진정으로 인해 시술 중 잦은 움직임을 보여 쉽게 진정에 실패하게 된다. 진정 실패 시 고려 할 수 있는 대안은 추가적인 약제 투여로 인한 재진정의 유도나, 좀 더 깊은진정법으로의 전환이 있다 그러나 갚은진정법으로의 전환은 환아의 움직임과 동통의 감소를 위해 흡입마취재 및 마취기계가 요구되어 외래 진료실에서는 쉽게 선택되지 못한다. EMLA cream(Eutectic Mixture of Local Anesthesia)은 피부의 도포마취를 위해 널리 사용되고 있는 약제로 본 증례에서는 이를 이용하여 자극 없이 정주진정 경로를 확보하여 경구진정에서 정주진정으로의 전환에 성공하였다. 만 46개월, 체중 15 kg 남아가 다발성 우식을 주소로 단국대학교 치과대학 병원 소아치과에 내원하였다. 일반적인 행동조절 하에 치료 권유하였으나 보호자의 요구에 의해 경구진정 시도하였으며, 경구진정 실패를 고려하여 복용 전 EMLA cream을 사전 도포하였다. 경구 복용 90분 경과 뒤에도 진정효과를 얻지 못하여 보호자의 동의하에 아산화질소를 이용하여 얕은진정 유도 후, EMLA cream 도포 부위에 정맥로를 확보하였다. 총 시술 시간 2시간 30분으로 특별한 부작용 없이 성공적으로 시술을 완료하였다. The use of chloral hydrate and hydroxyzine for oral sedation is most effective in children aged less than 36 months and weighing less than 15 kg. Children who do not belong to this category may show frequent movements due to shallow sedation level, and it can lead to sedation failures. One of the solutions to such sedation failure is conversion to deeper sedation. But, it is not so much of an option, since inhalation anesthetics and devices are required. In this case, conversion from oral sedation to intravenous sedation was successfully achieved without causing injection pain while searching for an intravenous route, by using EMLA cream (Eutectic Mixture of Local Anesthesia). A patient aged 46 months and weighing 15 kg visited the Pediatric Department of Dankook University Dental Hospital. Treatment under TSD(Tell Show Do) was offered, but due to the parent's request, oral sedative measures were taken. Considering prompt converting from oral sedation to iv sedation in case the oral sedation fails, EMLA cream was apllied preemptively. Adequate sedation level could not be achieved after 90 minutes of oral administration, therefore, under the parent s consent, intravenous route was prepared after conscious sedation by N₂O-O₂. During treatment, ETCO₂, SPO₂and heart rate was monitored every 5 minutes. The patient showed stable vital signs and did not show any movements. The whole procedure took two and a half hours in total, and the treatment was completed without any adverse effects.

C++를 이용한 통신 시뮬레이터의 설계 및 구현

이광휘,정상국,안정희,김한경,이종근 國立 昌原大學校 精報通信硏究所 1998 精報通信論文集 Vol.2 No.-

In this paper, we are designed and implemented communication simulator, for two systems which communicates in peer-to-peer and simulating for protocol, to verify the interwork not yet designed system Peerl and now being operated Peer2. To begin with, after the investigation in Interworking Standard in Interface Control Document and check the satisfied requirements in each system, the environment of simulator is set up. We examine Interworking Standard in FSM representation. And in protocol design, partial steps follows necessary procedure of protocol engineering. Simulator is implemented in C++ and, to interwork two systems smoothly, the whole system will be merged. Finally, a design and implementation of simulator is completed by confirming simulation results of simulator and Interworking Standard coincide.