고속 반도체 광변조기의 설계 및 성능평가에 관한 연구

李鐘昌,崔旺燁 弘益大學校 科學技術硏究所 2001 科學技術硏究論文集 Vol.12 No.-

In this paper we investigate the phase efficiency in the electrooptic phase modulator using PPpinNN GaAs / AlGaAs W waveguide. The phase change is affected by the refractive index change taking place inside the depletion region. The behavior of the modulator can be understood in terms of two electric field-related and two carrier-related effects linear electrooptic, quadratic electrooptic, plasma, and bandgap shift. As a result, the phase modulation efficiency was measured about 34.6[˚V·mm] for the TE polarized light. The quadratic electrooptic coefficient R = 5.82 x 10^(-15) [㎠/V²] is obtained and the phase efficiency caused by the quadratic electrooptic effect is about 10 times larger than that from the conventional linear electrooptic effect.

협업 여과 기반의 교육용 컨텐츠 추천 시스템 설계

이용준,이세훈,왕창종 한국컴퓨터교육학회 2003 컴퓨터교육학회 논문지 Vol.6 No.2

협업여과는 흥미 있어하는 제품이나 개인화된 자료, 항목을 제공하기 의해 전체 집단의 의견을 반영하는 전자상거래에서 일반적으로 이용되는 기술이다. 협업여과는 정확하고 신뢰할 수 있는 도구로 입증되어 여러 분야의 전자상거래 영역에서 활용되고 있으나 아직까지 교육분야에는 한정적으로 적용되고 있다. 본 논문에서는 교육용 컨텐츠 추천에 사용자의 평가 점수를 이용하는 협업여과 방식의 추천시스템을 설계하였으며, 사용자 정보를 이용하여 추천의 정확도를 향상시키기 위한 유사도 보정기법을 도입하였다. 평균절대오차(MAE)와 반응자작용특성(ROC)값을 이용하여 제안한 시스템이 기존의 협업여과방식보다 추천 효율이 우수함을 검증하였다. Collaborative Filtering is a popular technology in electronic commerce, which adapt the opinions of entire communities to provide interesting products or personalized resources and items. It has been applied to many kinds of electronic commerce domain since Collaborative Filtering has proven an accurate and reliable tool. But educational application remain limited yet. We design collaborative filtering recommendation system using user's ratings in educational contents recommendation. Also We propose a method of similarity compensation using user's information for improvement of recommendation accuracy. The proposed method is more efficient than the traditional collaborative filtering method by experimental comparisons of mean absolute error(MAE) and reciever operating characteristics(ROC) values.

EduCODE : SCORM 지원 교육용 컨텐츠 개발 방법 Educational Contents Development method for SCORM supporting

서대우,이세훈,왕창종 한국컴퓨터교육학회 2002 컴퓨터교육학회 논문지 Vol.5 No.4

이 논문에서는 교육용 컨텐츠 개발 방법인 EduCODE를 제안하고 이를 지원하는 시스템을 설계 및 구현하였다. EduCODE는 영역 모델, 항해 모델, 추상 인터페이스 모델, 애셋 모델 등 4개의 모델로 구성하였으며, 컨텐츠의 구성을 다이어그램으로 표현할 수 있는 표기법을 제안하였다. EduCODE를 지원하기 위한 자동화 시스템은 저작 모듈과 실행 모듈로 구성되어 있으며, 저작 모듈에서 생성된 각 명세서는 국제적인 교육용 컨텐츠 표준인 ADL SCORM XML 코드를 자동으로 생성하고 실행 모듈과 웹 서버를 통해 서비스된다. In this paper we proposed EduCODE for educational contents development method and designed the system to support EduCODE. There are four models in EduCODE such as domain model, navigation model, abstract interface model, and asset model. The method includs graphic notations for contents structure. The system to support EduCODE consisted of authoring module and run-time module. The authoring module automatically generates ADL SCORM XML code using specifications produced by EduCODE and the code is serviced to a client by run-time module and web server.

個人 및 團體競技選手와 非選手의 運動貧荷强度別 心博數 比較

金永煥,秋健二,王昌鍾 仁荷大學校 스포츠 科學硏究所 1989 論文集 Vol.1 No.-

This experimental study is to find out the physical endurance through heart rates according to the intensity of exercise. The experiment was applied to personal-game players in athletics, swimming, boxing and skating, and to team players in handball, volleyball, basketball and soccer, and to non-players. The intensity of exercise was divided into five kinds (12, 18, 24, 30, 36 times/minute) according to the speed of going up and down the wooden steps made for the test. Heart rates were measured while players and non-players under test were resting from one minute and a half to two minutes after exercise. The measurement of heart rates, twice in all, was took once every second day by using 108 system heart checker. T-test were applied to find out the average difference among three groups. 1. Heart rates of personal-game players were as follows: 131.0±10.53 beats/minute during the exercise intensity of 12 times/minute; 136.2±12.28 beats/minute during 18 times/minute; 139.1±11.9 beats/minute during 24 times/minute; 141.1±13.3 beats/minute during 30 times/minute; 144.5± 6.92 beats/minute during 36 times/minute: 2. Heart rates of team game players ranged as follows: 131.8±8.3 beats/minute during the exercise intensity of 12 times/minute; 138.0±9.89 beats/minute during 18 times/minute; 143.4±9.11 beats/minute during 24 times/minute; 148.5±9.64 beats/minute during 30 times/minute; 156.2±8.42 beats/minute during 36 times/minute. 3. Heart rates of non-players were as follow: 154.2±13.85 beats/minute during the exercise intensity of 12 times/minute; 155.6±15.62 beats/minute during 18 times/minute; 164.6±12.88 beats/minute during 24 times/minute; 172.4±13.37 beats/minute during 30 times/minute; 189.6±16.49 beats/minute during 36 times/minute. 4. All of the personal and team-game players under test had more excellent physical endurance than non-players, and showed less heart rates when tested in the five kinds of exercise intensity. Especially, both of them indicated more physical endurance when the exercise intensity increased A small gap of difference arose among each personal and team-game player in heart rates under the exercise intensity of 30 times/minute, but personal game players indicated less heart rates than team-game players when the intensity became 36 times/minute. (P<0.05). The most significant of the results in this research was the fact that a wider difference came out between personal and team-game players during the exercise intensity of 36 times/minute.

The Return of an Old Worm: Cerebral Paragonimiasis Presenting with Intracerebral Hemorrhage

Koh, Eun Jung,Kim, Seung-Ki,Wang, Kyu-Chang,Chai, Jong-Yil,Chong, Sangjoon,Park, Sung-Hye,Cheon, Jung-Eun,Phi, Ji Hoon The Korean Academy of Medical Sciences 2012 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.27 No.11

<P>Paragonimiasis is caused by ingesting crustaceans, which are the intermediate hosts of <I>Paragonimus</I>. The involvement of the brain was a common presentation in Korea decades ago, but it becomes much less frequent in domestic medical practices. We observed a rare case of cerebral paragonimiasis manifesting with intracerebral hemorrhage. A 10-yr-old girl presented with sudden-onset dysarthria, right facial palsy and clumsiness of the right hand. Brain imaging showed acute intracerebral hemorrhage in the left frontal area. An occult vascular malformation or small arteriovenous malformation compressed by the hematoma was initially suspected. The lesion progressed for over 2 months until a delayed surgery was undertaken. Pathologic examination was consistent with cerebral paragonimiasis. After chemotherapy with praziquantel, the patient was monitored without neurological deficits or seizure attacks for 6 months. This case alerts practicing clinicians to the domestic transmission of a forgotten parasitic disease due to environmental changes.</P>

Size Dependent Absorption Spectrum of ZnO Nanocrystals

Chang Ho Jung,Wang Yongsheng,Suh Kwang-Jong,Son Chang-Sik Materials Research Society of Korea 2005 한국재료학회지 Vol.15 No.7

To investigate the dependences of the absorption spectrum and electronic structure properties on the ZnO nano-particle size, ZnO nanocrystals were synthesized by a sol-gel method. The absorption onset peak exhibits a systematic blue-shift with decreasing particle size due to the quantum confinement effect, as well as, with decreasing $Zn^{2+}$ concentration. The increase of particle size is mainly controlled by coarsening and aggregation step during the nucleation and growth of ZnO nano-particles. The onset absorption spectrum of ZnO colloids changes from 310 to 355 nm as $Zn^{2+}$ concentration increases from 0.01 to 0.1 mole. The average particle size as a function of aging- time can be determined from the absorption spectra. The freshly prepared nanocrystal size was about 2.8nm.

The fate of spargana inoculated into the cat brain and sequential changes of anti - sparganum IgG antibody levels in the cerebrospinal fluid

Kyu-Chang Wang(왕규창),Sun Huh(허선),Sung-Tae Hong(홍성태),Jong-Yil Chai(채종일),Kil Soo Choi(최길수),Soon-Hyung Lee(이순형) 대한기생충학열대의학회 1990 The Korean Journal of Parasitology Vol.28 No.1

Pepresentative Instance의 X-Total Projection의 효율적 계산방법

왕창종(Chang Jong Wang),이의섭(Ehi Seob Lee),윤경섭(Gyeong Seob Yun) 한국정보과학회 1985 정보과학회논문지 Vol.12 No.4

RI(Representative Instance)는 유니버설 릴레이션시스템에서 질의문에 나타난 속성의 집합 X에 관한 연결, [X]를 계산하기 위한 방법으로 제안되었다. 이는 질의어에 대한 대답을 만들어내기 위하여 RI의 토탈 프로젝션을 사용하자는 것이다. RI의 토탈 프로젝션을 효율적으로 만들어 내는 방법을 제안한다. Representative Instance as a method in which we compute [X], the connection on the set of attributes X that appears in the query, in the Universal Relation System. That is, the Total Projection of RI is used to make the answer for a query. We suggest the efficient method to operate the Total Projection of RI.

고양이와 정상 정중신경 체성감각 유발전위와 체온변화가 이에 미치는 영향에 관한 연구

김종수,정영섭,왕규창,조병규,최길수 대한신경외과학회 1990 Journal of Korean neurosurgical society Vol.19 No.1

To determine the normal median nerve somatosensory evoked potentials in cat and to evaluate the effect of temperature change, following experiment was done. Median nerve somatosensory evoked potentials(MNSEP) were recoreded in 45 mongrel cats at 38.5℃, the normal temperature range in cats, and in 8 cats of them MNSEP was recorded at 37.5℃, 36.5℃ and 35.5℃ additionally. The results were as follows : 1) Seven peak waves were always recorded and they were named as Ⅰ. Ⅱ. P₁, Ⅲ, N₁, P₂, N₂, and central conduction time(CCT) was thought as Ⅰ -N₁ interpeak latency and it was 5.81±0.53msec. 2) The peak latencies of all waves and CCT were increased gradually as temperature decreased. The latencies of the late waves increased more than those of early waves as temperature decreased except N₂.

철도차량 안전규정의 현장적용성 개선방안 연구

이창근(Lee Chang Guen),이수룡(Lee Soo Ryong),왕종배(Wang Jong Bae) 한국철도학회 2008 한국철도학회 학술발표대회논문집 Vol.- No.-

Nowadays there are lots of changes in the domestic railroad industries because of the reorganization in the industries, operation of KTX and expansion of city train in local areas. To cope with these changes effectively, domestic & abroad safety guideline and regulation were investigated and reviewed by railroad safety technical development project. Based on this project, domestic rolling stock safety regulation was established in the July and December on 2005. It`s been a 3 years after 2005 and to confirm whether there are some problems to applicate the regulation in the field like korail, the necessity of reviewing the regulation gains force. In this study, to improve the field application in rolling stock safety regulation, we investigated the results of integrated railroad audit system and internal safety regulation system in a train operator and also collected the opinions from train manufacturer. Then through the result of investigation and collection of the opinions, we proposed the amendment to the rolling stock safety regulation.