비평가인자 함수언어의 다중스레드 코드 생성을 위한 생성기의 설계

김홍읍,이형렬 김천과학대학 1998 김천과학대학 논문집 Vol.24 No.-

Non-strict functional language with implicit parallelism needs dynamic scheduling and synchronization, because of non-strict's mechanism. Multithreaded model is efficient parallel processing model to solve latency time, dynamic scheduling, synchronization problemby combination of dataflow mode and von Neumann model. This model's efficiency is determined by construcion of thread and source language. This paper's generator translates kernel language, intermediate code, from non-strict functional language with implicit parallelism. Now and then generator translates multithreaded code from kernel language through dataflow graph.

컴퓨터 게임의 서사적 특성

류홍렬 한국문학교육학회 2000 문학교육학 Vol.5 No.-

This thesis intend to understand the educational effectiveness of computer's game. For this aim, this thesis pay attention to the characteristics of the narrative in computer's game. The charateristics of the narrative in computer's game is consoldated in three. (1) Only the element of act is appeared in the narrative in computer's game. The computer's game intend the reader to connect the act. (2) The actant of narrative is simplified. (3) The cause and efeect is excluded from the narrative in computer' game. This characteristics is presented in reader's side. (1) The reader's active role is important in the construction of narrative in game. (2) The reader understand retrospectively the construction of narrative by selection. The reader understand the meaning of his owm selection when game end. (3) The reader construct his own amative by changing viewpoint. The game present the only possibility. It is reader's role to actualize this possibility. Thus the enjoyment of game's narrative is understood from narrative.

선의 굵기 정보 표현을 위한 세선화의 전처리 기법

이형렬,김홍읍 김천과학대학 2002 김천과학대학 논문집 Vol.28 No.-

Information representing the thickness of the original lines from the thinning results can be applied efficiently in order to implement the automated vectorizing system. This paper propose a preprocessing scheme of thinning which can show the information of the original lines' thickness of the thinning result. In the proposed scheme, the depth of each pixel constructing the lines of map was calculated, which was represented by the number of layers composed of neighboring pixels surrounding the original pixel. And then the original lines' thickness could be recognized through the depth information of the skeleton from the thinning results. We implemented the proposed scheme and experimented on a contour map. Using the depth information of the skeleton, we could easily distinguish each line of the contour either an intermediate or an index contour.

티타늄의 산화 조건에 따른 산화막의 특성 및 인산칼슘 생성에 미치는 영향

김인,양홍서,박연준,송호준,이용렬 전남대학교 치의학연구소 2003 구강과학 Vol.15 No.3

The objective of this study was to evaluate the changes of micro morphology, roughness and crystalline structure of titanium surface after various oxidation treatments. Moreover, the effect of titanium surface oxide characteristics on the formation of calcium phosphate in Eagle's MEM. Commercially pure Ti disks were treated at various thermal conditions of 530℃ (Ti-530), 600℃(Ti-600), 700℃(Ti-700), 800℃(Ti-800), 900℃(Ti-900), and 1000℃(Ti-1000), respectively, and as received cp Ti (AS-R) and passivated cp Ti (PAS) were used as comparison groups. Surface characteristics were investigated using FE-SEM, profilometer and XRD. After immersing each sample in MEM for 7days, calcium phosphate (Ca-P) formation was evaluated using FE-SEM and EDS. Crystallites of 10~30nm-size were observed on the surface of Ti-530 and Ti-600 samples. Needle-like crystals were formed on Ti-700 samples, and the crystal grain size was increased dramatically as the temperature increased higher than 800℃. The roughness of Ti-530 was higher comparing to AS-R and PAS, and the roughness decreased in the treatment range of 530-700 with dense crystalline oxide formation. However, at treatment temperatures higher than 800℃, the roughness increased and its degree was depended to the size of the crystals. The anatase structures were observed in Ti-530 and Ti-600, and anatase and rutile structures were co-existed in Ti-700 specimen. Only rutile TiO_(2) were observed in Ti-800, Ti-900 and Ti-1000 specimens. The Ca-P formation on AS-R and PAS specimens was low in MEM solution. However, the Ca-P formation was well observed on heat-treatedgroups, and its degree of formation and micro-morphology was different by the specimen groups. The crystalline and chemical structure, micro-morphology, and surface roughness of titanium were various by the conditions of heat treatments, and the grain size and crystal structure of titanium oxide affected on the degree of Ca-P formation on Ti samples in MEM solution

Calcium phosphate 결정 성장 최적화를 위한 Ti 표면의 BaTiO_3 박막 형성에 관한 연구

조진우,양홍서,박영준,황규석,송종은,이용렬 전남대학교 치과대학 2001 구강과학 Vol.13 No.2

This study was purposed to establish an optimized manufacturing process for a negatively charged ferroelectric thin flim on titanium substrate in order to develop a new implant system having the mechanical strength and bone forming ability. Ferroelectric materials show an alignment of positive and negative charges by poling treatment. Based on this property, this study was performed with the assumption that the Ca^2+ ions would be easily attracted on negatively charged surface and the attracted cation might behave as nuclei for bone-like crystal grownth in biological solutions. In order to have an osteoinducibility by the ferroelectric thin film coating, continuous and flawless crystalline thin film should be formed with ferroelectricity, and finally should be adequately poling treated. In this study, BaTiO_3 (BTO) was selected as a ferroelectric material. Before thin film coating process, most favorable poling condition was investiged with the evaluation of the difference in calcium phosphate (Ca-P) formation in simulated body fluid (SBF). Moreover, the parameters to form an optimum thin film were studied. Dense bulk BTO disks were fabricate using cold isostatic pressing(CIP) and sintered in air at 1300℃ for 2 hours. Sintered BTO disk was polished, and he crystallinity, microstructure, and ferroelectric characteristics were evaluated using an X-ray diffraction analysis (XRD), a field emission scanning electron microscope (FE-SEM), and an Impedance analyzer. To find the optimum poling condition for the calcium phosphate crystal formation, sintered bulk BTO specimens were treated with either of following poling conditions; 1) room temperature poling treatment [ polarizing field (Ep) = 25kV/cm, at 25℃ for 2 hours], 2) under Tc medium-temperaturepoling treatment (Ep=20kV/cm, from 85˚C to 25˚C for 2 hour), and 3) above Tc high-temperature poling were immesed in simulated body fluid (SBF) for 30 days, and the formation of calcium phosphate (Ca-P) layer n the surface was evaluated. The crystallinity, microstructure, and ferroelectric characteristic of BTO thin film were evaluated withthe variation of final heat treatment. It was performed after establishing the starting substance-solvent mixing ratio, coating times, and pre-heating temperature optimal to form continuous and flawless BTO thin film adequate for having ferroelectricity. Perparation of BTO thin film was made by dipping-pyrolysis technique using metal naphthenates as starting substances. BTO thin films was spin-coated on Ti substrate by dipping-pyrolysis technique using sol obtained by mixing Ba-naphthenate and Ti-naphthenate as starting substances. Pre-firing temperature of BTO thin film was performed at 450℃ because organic-solvent ws completely volatilized without any crystal growth, and the final heat treatment was performed at 600, 700 or 800℃, respectively. The results are as follows; 1. BTO disk sintered at 1300℃ for 2 hours showed average grain size of about 1㎛ and the relative dielectric constant at 1㎑ was abut 3000∼3500. 2. After immersing the sintered bulk BTO poled at respective conditions in SBF for 30 days, Ca-P layers were present on the negatively charged surfaces. In contrary, positively charged Bto surface did not show any noticeable charge of the surface microstructure after SBF immersion. 3. In he case of poling condition 1 and 2 treated with below Tc, Ca/P ratio showed a relatively low value of 1,.2∼1.5. While, in the case of poling condition 3 treated with above Tc, Ca/P ratio was 1.5∼1.67, which is similar to that of biological apatite. This phenomenon demonstrates that poling the BTO above the temperature of Tc is preferable for the Ca-P formation. 4. For thin film BTO coastin, the starting substance was prepared by an equimolar mixing of the Ba and Ti-naphthenate. Dilution of the starting substance with toluene was most appropriate at sol : toluene ratio of 5.2:4.8 Too thin sol produced porosity in film, and too thick sol resulted cracks in the film. By repeating the coating and pre-firing procedure 15 times, homogeneous film of 0.5㎛ thickness could be fabricated, and perfomed well during the poling treatment without breakdown. 5. The heat-treatmen of the BTO thin film at 700℃ produced a homogeneous crystalline structure without heterogeneous TiO2 formation. The BTO thin film heat-treated at 600℃ showed non-crystallinity and no ferroelectricity. Treatment at 800℃ produced heterogeneous TiO2 phase in the film, which is unfavorabe for having ferroelectricity by the distortion of the perovskite structure. The relative dielectic constant at 1 ㎑ was 152 and 112 by heat-treatment at 700 and 800℃, respectively. In summary, these results demonstrated that poling the ferroelectric B_aT_iO_3 surface negatively is effective for the formation of Ca-P layer in simulated body fluids. Poling condition at a temperature cooling from above Tc down to room temperature is most effective. By optimizing the method of BTO thin film coating on metal substrate for the formation of Ca-P layer, the data of this study might be applied for the manufacture of new bioactive implant system.

타타늄의 열처리 조건에 따른 동전위 양극분극특성 및 표면 미세구조 변화

주동현,이용렬,정영화,양홍서,박상원,이도재,송호준,박영준 大韓齒科器材學會 2002 대한치과재료학회지 Vol.29 No.2

The corrosion resistance of metallic implants is essential for successful implant osseointegration. Moreover, the implant surface should have appropriate surface roughness for the attachment of the osteoblast and collagen fibrils. When titanium is exposed to air a thermodynamically very stable oxide film is formed at once. This oxide is very thin and yet it protects the metal from corrosion instantaneously. However, the oxide would not be ideal, and it would be supposed that the state of oxide film would be various by the different conditions when it is formed. The objective of this study was to evaluate the electrochemical properties and surface microstructural changes of titanium after passivation treatment or exposure to high heat (in vacuum or in air). ASTM grade 2 commercially pure titanium (Ti) disks of 10㎜ diameter were wet ground and polished with 240 and 600 grit SiC, and then ultrasonically cleaned with distilled water and ethanol. Cleansed as-received samples (As-R group) were passivated with 30% nitric acid solution at 50℃ for 15 minutes to make the Pas group. The Std-V samples were made by treating the Ti disks in vacuum quartz tube (10^-8 Torr) at 530℃ for 40 min for stress relieving, followed by annealing at 700℃ for 90 min, and then slow cooling to room temperature. The Std-A samples undergo identical procedure as the Std-V group except that it is done in air. For 530℃-V samples, Ti disks were heated at 530℃ for 40 minutes and slow cooled to room temperature. The 1000℃-V samples were produced by heating Std-V specimens again at 1000℃ for 2 hr, followed by cooling to room temperature. 530℃-A and 1000℃-A samples were also prepared. Potentiodynamic anodic polarization measurement, SEM, AFM and XRD analysis were performed to evaluate the effects of the various treatments. The difference in the mean values of E_corr between groups showed statistically significant difference (P<0.05), but that of I_corr did not show significance (P>0.05). When Ti surface was passivated there was a shift of corrosion potential (E_corr) in the noble direction and a lower corrosion current density (I_corr) value. Std-A samples showed most noble E_corr value among the tested groups. 530℃-V samples showed more noble E-corr than other tested groups except Std-A group. 1000℃-V samples showed more noble E-corr than those of Std-V sample. In the case of Std-, 530℃- and 1000℃-groups, -A sub-groups showed better corrosion resistant characteristics than -V sub-groups in regard to E-corr and I_corr values. In the SEM observations, the surfaces of the As-R samples showed only scratch line on smooth surface. In Pas samples, thick oxide layer covered the surface under high magnification observation. 530℃-A samples were covered by oxide granules, and Std-A samples had 25~50 nm-thick acicular oxides. The 1000℃-A samples were covered by coarse oxide crystals with a granule diameter of 0.1~0.6 μm having a gross appearance of milky white color, which was identified by XRD as a rutile. On the other hand, 1000℃-V samples showed an Widmansta¨tten structrue of which the orientation of the lattice is formed along crystallographic planes of the parent crystals. On the AFM observation, 530℃-A samples showed RMS roughness of 79.38 nm which is 5 times rougher than those of the As-R samples. Std-A sample had a roughness of 330.47 nm which is about 20-times rougher than that of the As-R sample. 1000℃-A samples were covered by coarse granular oxides and the roughness were about 0.56 μm. Vacuum sub-group samples showed a more smooth surface than air sub-group samples, and the oxide film was more dense. Due to variability of the surface treatment and heat treatment conditions, the process of the oxide formation seems to be affected thereby making the corrosion properties and surface micro-morphology different. However, more various electrochemical analysis together with surface analysis, and an investigation for the effects of those on the osteoblast cell adhesion and calcium phosphate apposition are needed for the improvement of the osseointegration rates of the titanium implants.

木浦地方의 안개發生特性

蘇鮮燮,全閏南,申弘烈 공주대학교 사범대학 과학교육연구소 1996 과학교육연구 Vol.27 No.1

안개는 수증기의 供給源인 바다, 호수, 강, 인공댐 및 태양 에너지의 입사량 변화로 發生하게 된다. 목포지방은 三面이 바다로 둘러 싸여 있으며, 주변의 造成된 영산강 댐과 2개의 人工 호수 때문에 안개 發生에 좋은 조건을 갖추고 있다. 본 硏究는 목포지방의 안개 發生 特性을 밝히기 위하여 안개 發生日數, 特續時間, 風向, 風速, 氣溫과 水溫의 偏差를 비교 分析하였다. 또한 안개의 發生 및 消散시각의 분포에 따라 4가지 Case로 분류하고 氣象要素의 變化에 따른 안개의 視程 변화를 分析해 본 결과 夏節期에는 따뜻하고 수증기를 많이 포함한 空氣가 찬 바다 위로 이동하면서 移流안개가 발생하고 봄·가을에는 氣溫의 日較差에 의해 輻射안개와 ??發안개가 複合的으로 나타난다. A fog is variously induced by the sea, the lake, the river, the artificial dam and the solar energy which originate the vapor. The Mokpo area is surrounded by the sea, the Youngsan river and the artificial lakes which naturally tend to cause a dense fog. This research shows the analogy and comparison to prove the traits of what made a fog in the Mokpo area; how many days a month the fog originates; how many hours it lasts, both the direction and the velocity of the wind, and the anomaly between atmos-pheric temperature and the sea-water temperature. The types of the fog occurrence and the dstribution of the fog-clearing time are classified into four cases. This research also tells that as a result, the change of the fogcl-earing speed brings those facts as follows: (i) when the air, warm and vaporous, is d-rifted away over the cold sea-water in the summertime; (ii) it makes the advection fog and in the season of spring and fall, it makes both the evaporation fog and the radiati-on fog at the same time, due to the great daily temperature difference. The fog in Mokpo area has high occurrence-frequency both when the velocity of the wind runs below 3 m/s and when the direction of the wind indicates NNW,NW,SSW,SSE, etc...

ICT 활용 교육을 위한 원격지 학급간 협동 학습 시스템 개발

정영식,이영현,김홍래,김명렬 한국컴퓨터교육학회 2002 컴퓨터교육학회 논문지 Vol.5 No.2

인터넷을 기반으로 한 원격지 학급간 협동 학습 시스템은 원격지 학급을 연결하는 매칭 시스템, 다양한 보상 체계와 상호 작용으로 실질적인 협동 학습이 이루어질 수 있도록 한 커뮤니티 시스템, 개인이나 모둠 및 학습실의 학습 성취도를 평가하고 학습 결과물을 공유할 수 있는 리포트 시스템으로 구성하였다. 특히 협동 학습 과정을 사전 준비 단계, 모둠 구성 단계, 상호 작용 단계, 결과협의 단계, 평가 정리 단계로 구분하여 시스템에 적용시켰다. 이 시스템은 다양한 상호 작용과 책임 있는 모둠 활동을 제공하므로 교사는 자연스럽게 ICT 활용 교육에 자신감을 갖게 되고, 학생은 정보화 사회에 필요한 기초적인 ICT와 공동체 의식을 습득할 것이다. A remote cooperative studying system based on the Internet consists of a matching system of connecting remote class room with the others, a comunity system of making practical cooperative study by student's various, compensation and interaction, and a report system of sharing studying results and evaluating of studying achievements for individuals, groups and class, Especially I divide a course of cooperative studying into six parts; pre-preparation stage, group organization stage, interaction stage, result consultation stage. evaluation stage and follow-up stage. Because this system supply various interaction and responsible activity of groups, teachers naturally have confidence of education using ICT and students have basic ICT and the community-sense

Matlab/Simulink를 이용한 DC 서보 전동기의 속도제어에 관한 시뮬레이터 개발

장영학,주신형,김홍렬 木浦大學校 工業技術硏究所 1999 工業技術硏究誌 Vol.9 No.-

This paper presents a modeling method of a speed control for DC servo motor. This System is modeled by using the system level simulation program, Matlab/Simulink. The main purpose of this simulator is related to the development and validation of advanced control techniques applied to DC motors In Matlab/Simulink, a graphic user interface is supported, and system structures can be easily visualized. In the developed simulator, the subsystems of DC motor are implemented using three ways; modeling for the DC motor, PID auto-turning, stability. To simulate a speed control for DC motor in the simulator, the blocks or modules, which are elements of a control system, are simply connected by lines. The simulation results can be displayed using the built-in graphic functions in Matlab in Matlab or the scope; which is one of the block libraries in Simulink. The adoption of this simulator improves mpdularity, reusability and productivity in studying a Control system.

Toward the Personal Robot Software Framework

Hong Ryeol Kim,Dae Won Kim,Hong Seok Kim,Ho Gil Lee 제어로봇시스템학회 2002 제어로봇시스템학회 국제학술대회 논문집 Vol.2002 No.10