A Study of Electro-Optical Crystal as a Diagnostic Tool for Low Energy Electron Beam

박용운,김창범,고인수,Jangho Park,황정연,주태하 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.I

The short, intense, and low emittance electron beams are crucial to make high quality X-ray beam for X-ray free electron laser (XFEL). A RF photo-cathode (RF PC) gun of 1.6 cell cavity is installed at Gun Test Stand (GTS) in Pohang Accelerator Laboratory (PAL). For the successful construction of PAL-XFEL, the bunch length of the beam should be measured accurately at the exit of the gun where the beam energy is 4.5 MeV. Electro-Optic Sampling (EOS) is a very promising method to measure the bunch length non-destructively. An experiment with D.C. voltage setup is done to verify the electro-optic (EO) crystal can be used as a diagnostic tool for low energy beam. A simulation study is also done with a pulse propagation method which is based on the Fourier transform that allows us to investigate the dynamical evolution of electromagnetic pulse in the EO crystal. The simulation result shows that the signal level can be about 20 \% of the initial laser pulse signal. From the experiment and the simulation, we have convinced that the EOS can be a non-destructive diagnostic tool for low energy beam for XFEL.

국방로봇-감시 정찰에서 전투까지 로봇이 대신한다

박용운,Park, Yong-Un 한국과학기술단체총연합회 2007 과학과 기술 Vol.40 No.7

모돈의 번식능력 향상방안

박용운,Park, Yong-Un 대한양돈협회 1987 養豚 Vol.9 No.3

이중 캐쉬 서버를 사용한 실시간 데이터의 좡대역 네트워크 대역폭 감소 정책

박용운,백건효,정기동,Park, Yong-Woon,Beak, Kun-Hyo,Chung, Ki-Dong 한국정보처리학회 2000 정보처리논문지 Vol.7 No.10

연속형 미디어 데이터는 대용량이고 실시간으로 전송되어야 하므로 데이터 전송 시에 네트워크에 많은 부하를 주게 된다. 이러한 네트워크는 부하 문제를 해결하기 위하여 프락시 서버가 사용되며 프락시 서버에는 자주 접근되는 데이터가 저장되어 원래의 데이터가 존재하는 서버로의 네트워크 교통량을 줄이게 된다. 그러나 현재의 프락시 서버는 텍스트나 이미지 데이터등의 비 연속형 데이터만을 고려하여 설계되었으므로 연속형 미디어 데이터의 캐슁에는 적합하지 않다. 그러므로 본 연구에서는 연속형 미디어 데이터의 특징을 고려하여 프락시 서버를 두 계층으로 나누어 배치하여 데이터를 캐슁하고 데이터의 접근 패턴과 크기를 동시에 고려한 재할당 정책을 사용하여 캐쉬공간을 관리하는 프락시 서버 관리 정책을 제안한다. 제안된 정책에서는 각각의 LAN 마다 하나의 프락시 서버가 존재하며 각 LAN은 여러 개의 서브LAN으로 나뉘어 져서 이러한 각각의 서브 LAN에는 또한 하나의 서브 LAN 프락시가 존재한다. 이에 병행하여 각각의 데이터들도 각각 전방 분할(front-end partition)과 후방 분할(rear-end partition)로 나뉘어져서 해당 데이터의 참조 유형에 따라 하나의 프락시에 동시에 저장되기도 하고 LAN 캐쉬 서버와 서브 LAN 캐쉬 서버에 각각 따로 저장되기도 한다. 이러한 정책을 사용함으로써 전체 데이터를 단위로 캐슁할 경우보다 데이터공간의 할당과 재할당에 따른 오버헤드가 감소함으로써 궁극적으로는 원래의 저장 서버로의 네트워크 교통량을 보다 더 감소시킬 수 있다. Continuous media objects, due to large volume and real-time consiraints in their delivery,are likely to consume much network andwidth Generally, proxy servers are used to hold the fiequently requested objects so as to reduce the network traffic to the central server but most of them are designed for text and image dae that they do not go well with continuous media data. So, in this paper, we propose a two-layered network cache management policy for continuous media object delivery on the wide area networks. With the proposed cache management scheme,in cach LAN, there exists one LAN cache and each LAN is further devided into a group of sub-LANs, each of which also has its own sub-LAN eache. Further, each object is also partitioned into two parts the front-end and rear-end partition. they can be loaded in the same cache or separately in different network caches according to their access frequencics. By doing so, cache replacement overhead could be educed as compared to the case of the full size daa allocation and replacement , this eventually reduces the backbone network traffic to the origin server.

[ITS 부문] 전투차량용 정보처리/전시 장비

박용운(Yongwoon Park),강윤식(Younsik Kang),백인철(Inchul Hak),박규철(Kyuchul Park),박준성(Junsung Park) 한국자동차공학회 2000 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Recently, some of the passenger vehicles use the navigation system which have the map on the background with related informations for the driver. Similar system has been used in the combat vehicles to enhance the combat readiness and information sharing for the crews. This research presents the Information Processing and Display System(IPDS) which has been developed for the validation of combat vehicle adaptation. Most of the contents cover the function of the map display with related<br/> information with respect to the operational environment, symbol, navigation and position, and information and data communications.

고려(高麗)·송(宋) 교빙(交聘)의 목적과 사절(使節)에 대한 고찰 (上)

박용운 ( Yong Woon Park ) 일지사 1995 韓國學報 Vol.21 No.4

고려시기의 兼職과 重複職에 대한 논의와 권력구조

박용운(Park Yong-Woon) 한국사연구회 2007 한국사연구 Vol.136 No.-

The Royal Secretariat-Chancellery(中書門下省), the Department of state affairs(尙書省) and the Security Council(中樞院ㆍ樞密院) were the essential political institutions which administered the all the affairs of Goryeo court. It was characteristic of Goryeo dynasty for government officials to hold concurrent posts if they were appointed to take an additional duties, or even have two or more posts assigned to them simultaneously. For example, those who held one of the posts of Grand Councilor of the Royal Secretariat-Chancellery(宰臣) were routinely assigned to posts within the Controller for Six Ministries(6部判事) as well. The Grand Councilors of rank 2b(從2品) and below, as well as officials from the Seven posts of the Security Council, would commonly be assigned positions of Vice Director(僕射), Controller for Six Ministries(6部尙書), Chief Attendant(散騎常侍) and Censor-in-Chief(御史大夫). As different viewpoints have been suggested, the issue that lies here is how one should understand the nature of the structure of the posts of Grand Councilor of the Royal Secretariat-Chancellery and the Seven posts of the Security Council. Furthermore, the question arises, are these posts concurrent positions, in which one post being held by an official is dependant on his other position, or he holds plural posts, in which they are independent from each other? This is an issue which is closely related to understanding the power structure of the dynasty. The former assumption stresses the king’s absolute power over executive officials in his administrative court while the latter emphasizes these officers also maintained a certain degree of power. The theory of concurrent posts is supported by the fact that the king always held final decision, and the Six Ministries of the Department of State Affairs could consult directly with the king without the consent of any higher institutions. However, the Six Ministries were more or less under the Grand Councilors’ influence, as these councilors held the post of Controller of the Ministries. Furthermore, the councilors could practice their influence over appointing Censors, who’s duties were to debate policies, through the verification system. Considering these points, it would be more appropriate to regard the posts of Grand Councilor of the Royal Secretariat-Chancellery and the Seven posts of the Security Council as independent, because their opinion could affect the king’s decisions. Although the Goryeo kings had less control over the dynasty than the Joseon kings, it is evident that the well balanced power between the king and his highest officers was the defining feature that shaped the whole Goryeo government.

NiO 게이트 산화막에 의한 AlGaN/GaN MOSHFET의 전기적 특성 변화

박용운(Yong Woon Park),양전욱(Jeon Wook Yang) 한국전기전자학회 2021 전기전자학회논문지 Vol.25 No.3

AlGaN/GaN 반도체 위에 금속이 접합된 HEMT와 SiO2와 NiO를 게이트 층간막으로 갖는 MOSHFET를 제작하고 NiO 박막에 따른 효과와 특성변화의 원인을 연구하였다. HEMT 구조에서 보인 -3.79 V의 문턱전압은 SiO₂를 층간막으로 했을 때 - 5.52 V로 -1.73 V의 음방향 변화를, NiO를 층간막으로 했을 때 -2.76 V로 +1.03 V의 양방향 변화를 나타냈다. 또 NiO MOSFET의 경우 선형성이 증가하여 넓은 범위에 걸쳐 균일한 트랜스컨덕턴스 특성을 나타냈으며 0 V 이상의 게이트 전압에서는 HEMT와 SiO₂ MOSHFET보다 더 높은 값을 보였다. 게이트에 입력된 펄스신호가 -5 V∼0 V로 스윙할 때 HEMT의 포화 드레인 전류는 0.1 Hz∼10 Hz의 주파수에서 20%의 감소를 보인 뒤 그 값을 유지하였으나, NiO MOSHFET은 10 Hz에서부터 지속적으로 감소하여 서로 다른 응답특성을 보였다. The electrical characteristics of AlGaN/GaN/HEMT and MOSHFETs with NiO were studied. The threshold voltage of NiO MOSHFET revealed positive shift of +1.03 V than the -3.79 V of HEMT and negative shift of -1.73 V for SiO₂ MOSHFET. Also, NiO MOSHFET showed better linearity in drain current corresponding to gate voltage and higher transconductance at positive gate voltage than the others. The response of gate pulse with base voltage of -5 V was different for both transistors as HEMT showed 20 % drain current decrease at the frequency range of 0.1 Hz∼10 Hz and NiO MOSHFET decreased continuously above 10 Hz.

고려후기 權門의 用例와 그 성격에 대한 재검토

박용운(Park Yong-woon) 고려사학회 2003 한국사학보 Vol.- No.14

고려시기 科擧에서의 行卷과 家狀

朴龍雲(Park Yong-woon) 한국사연구회 2010 한국사연구 Vol.148 No.-

The candidates for the state civil service examination in the Goryeo period must have submitted two kinds of particular documents to the state department in charge, Gongwon(貢院) of the Ministry of Rites(禮部) before the examination. The documents were called Haenggwon(行卷) and Gajang(家狀). Haenggwon was, in fact, a bunch of papers bound together that demonstrates the candidate's composing poems and prose skills. The other document, Gajang, contained the necessary information of the candidate's main family members. The basic regulations for these two documents and their submission were believed to be established sometime during 1091 ~ 1116, and were in action till the end of the dynasty. According this regulation the candidates for the civil service examination usually presented the two documents at least two months before the examination date, so the examiners could have enough time to appraise the individual candidate's overall capability as well as his social rank, on which the information of the candidate's family members could tell, during the sixty days. However, the actual deadline for submission showed slight changes according to period. And for the unfortunate candidates who happened to lose their family members, the ministry in charge of the examination often exceptionally extended submission date. Reading the two documents before the examination was in fact an appraisal of the applicants' qualifications. This process also revealed not only the applicant himself but his own family members who might already have been officials of the government. It is highly possible that the information on the newly recruited officials, which was pre-acquired via Haenggwon and Gajang documents, affected the crucial post recruitment process such as identification and immediate appointment. The state civil service examination was a recruiting system fundamentally based upon the applicant's ability. However, looking inside the actual operating aspect of the examination system, submission of the Heanggwon and Gajang documents for instance, it is clear to see that the recruiting system was run in favor of the renowned aristocratic families. It also, once again. confirms the aristocratic feature of the Goryeo dynasty.