ISC3모델을 이용한 버스터미널 주변의 질소산화물 농도 예측

김문찬,류효상 청주대학교 산업과학연구소 2008 産業科學硏究 Vol.26 No.1

In this study, NOx concentration was investigated around the local/highway bus terminal area by using ISC3 model. NOx concentrations were simulated by the yearly mean values which were in the morning, in the afternoon and at night. As the result of the verification and the calibration for the model accuracy, the correlation coefficients was 0.94. Therefore, ISC3 model was suitable for this area. In the result of NOx concentration using ISCLT3, the average concentration of NO2 was 13.05 ppb. The range of influence that engine emissions affected terminal area, was larger in the morning than in the afternoon. Because mixing height was higher in the afternoon than that in the morning, so emissions were diffused toward upper ambient air that range of engine emission influence was narrow. At night, the range of engine emission influence was the largest in a day. Because mixing height was the lowest at night. So horizontal diffusion was dominated than vertical one.

주문-조립시스템의 설계 및 성능평가

박찬우,이효성 한국경영과학회 2002 한국경영과학회지 Vol.27 No.4

We study multi-component production/inventory system in which individual components are made to meet various demand types. We assume that the demands arrive according to a Poisson process, but there is a fixed probability that a demand requests a particular kit of different components. Each component is produced by a flow line with several stations in which the processing times of each station follow a two-stage Coxian distribution. The production of each component is operated by an independent base-stock with blocking. We assume that the time needed to assemble final products follows a general distribution and the capacity of an assembling facility is sufficiently large. The objective of this study is to obtain key performance measures such as the distribution of the number of each orders for each final product and the mean time of fulfilling a customer order. The basic principle of the proposed approximation methods is to decompose the original system into a set of subsystems, each subsystem being associated with a flow line. Each subsystem is analyzed in isolation using a method. As iterative procedure is then used to determine the unknown parameters of each subsystem. Numerical results show that the accuracy of the approximation method is acceptable.

Trace-forward만을 사용한 Viterbi Decoder

노승효,오승훈,이찬호 崇實大學校 1999 論文集 Vol.29 No.1

Recently, the Viterbi algorithm is widely used for the decoding of convolutional codes. This paper proposes a Viterbi decoder using a trace-forward processing to reduce the amount of memory storing the survivor path information and to increase the decoding speed. We adopt fully parallel structure for ACS(add-compare-select) units to minimize the delay which determines the Viterbi decoder's throughput. We reuses ACS units to reduce ACS area that occupies the majority of the chip area. The decoder is designed using VHDL and is implemented using a CPLD. It is verified to operate by a measurement using a logic analyzer.

완제품에 대한 수요가 Compound Poisson 과정에 따라 발생하는 CONWIP System의 성능분석

박찬우,신경화,이효성 한국경영과학회 2002 한국경영과학회 학술대회논문집 Vol.- No.1(2)

In this study we consider a flow-line CONWIP System with Compound Poisson Demands. The processing times of each workstation follow a Coxian-2 distribution. The demands that are not satisfied instantaneously are either backordered or lost according to the number of backordered demands that exist at their arrival instants. For this system we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of parts at each station, the average number of backordered demands and the proportion of the lost demands. Comparisons with simulation have shown that the approximate method provides fairly good results.

카올린으로부터 액상침전법에 의한 미립 알루미나 합성

박희찬,강효경,김병찬,박성수 釜山大學校生産技術硏究所 1999 生産技術硏究所論文集 Vol.56 No.-

카올린으로부터 미립 일루미나 분말을 합성하였다. 황산용액을 이용하여 액상침전법으로 알루미나를 추출하였다. 알루미나 추출에 미치는 황산농도, 반응온도 및 반응시간의 영향을 조사하였다. 이 과정에서 수화 황산알루미늄이 용출액으로부터 석출되었다. 이때 석출제로는 에탄올을 사용하였다. 이 석출물을 가영하여 미립 알루미나 분말을 얻을 수 있었다. DTA, SEM, TEM 및 XRD를 이용하여 분말의 특성을 조사하였다. Fine alumina was synthesized from kaolin. The alumina was prepared by liquid phase precipitation method using H?SO? solution. The effects of acid concentration, reaction temperature and reaction time on alumina extraction were investigated. Using an ethanol as precipitating agent, hydrated aluminum sulfate was precipitated from leach liquor. Fine alumina powder was obtained by calcining the precipitate. DTA, SEM, TEM and XRD were employed to characterize the powder.

프랑스어 및 한국어 구강모음의 비교연구 : 컴퓨터 단층 촬영 및 디지틀 음향분광기를 사용하여 by means of Computed Tomography and High-speech Analysis System

김찬양,신효근,홍기환,김연희,김현기 全北大學校 語學硏究所 1994 어학 Vol.21 No.-

The methods of the Computed Tomograph and the High-speed Speech analysis system were used for the comparative study of French and Korean oral vowels. Three male native speackers of French and three Korean speakers were selected for these articulatory and acoustic characteristics. The speech materials were the simple French oral vowels / i, e, ε, a, u, o, ??, a / and the Korean oral vovels / i, e, ε, a, w, u, o /, respectively. The results of these studies are as follows : (1) In the case of articulation, the aperture of Korean closed front unrounded vowels is larger than that of French vowels and the Korean back closed vowel /u/ and the half-closed vowel /o/ did not show significant differences with the corresponding French high vowel /i/. But the aperture of the Korean half-open vowel /??/ is smaller than that of French vowel and in this case, the place of articulation for Korean vowel /??/ is more advanced than that of French vowel /??/ (2) By means of spectrographic analysis of the French and Korean vowels, the first formant of the Korean high vowel /i/ is higher than that of French high vowel /i/. This means that the aperture of the Korean high vowel is larger than that of French high vowel. The second formant of French back vowels are lower than those of Korean back vowels. This result shows that the projection of French back vowels is greater than that of Korean back vowels.

카올린으로부터 합성된 고순도 알루미나의 γ→α변태에 미치는 Fe₂O₃첨가의 영향

강효경,박성수,박희찬 釜山大學校生産技術硏究所 1997 生産技術硏究所論文集 Vol.53 No.-

국내산 카올린으로부터 알루미늄황산염수화물을 합성하고, 이의 특성 및 열분해에 따른 알루미나의 γ→α변태에 미치는 Fe₂O₃의 첨가효과가 X-선회절분석, 시차열중량분석, 주사전자현미경, 플라즈마분광분석, BET법을 이용하여 검토하였다. 합성된 2 ㎛정도 크기의 판상입자형태로 구성된 고순도 알루미늄황산염은 Al₂(SO₄)₃·18H₂O로 동정되었으며, 이는 150℃ 부근에서의 탈수반응과 750℃부근에서의 탈황산반응을 경유하여 1000℃에서 결정성이 낮은 γ-Al₂O₃로 변화하였고, γ→α변태는 1200℃정도에서 일어났다. 0.1 wt% Fe₂O₃를 첨가한 경우의 1200℃하소물에서 생성된 FeAl₂O₄스피넬은 알루니마의 γ→α변태를 억제시켰으며, 그 이상의 양을 첨가한 경우와 1300℃로의 하소온도를 증가시킨 경우는 FeAl₂O₄의 α-Al₂O₃와 Fe₂O₃로의 분해 및 이온확산속도의 증가로 인하여 α-Al₂O₃생성이 촉진되었다. Aluminum sulfate hydrate has been prepared from the domestic kaolin, and its characteristics and the effect of Fe₂O₃addition on the γ→αtransformation of the resulting alumina have been investigated by means of the XRD, TG/DTA, SEM, plasma spectrometer, and BET methods. The aluminum sulfate having high purity and 2 ㎛-sized plate-like structure particles was identified as a crystalline Al₂(SO₄)₃·18H₂O, and decomposed to γ-Al₂O₃at 1000℃ via dehydration at ∼150℃ and desulfurization at ∼750℃. γ-Al₂O₃transformed to α-Al₂O₃at 1200℃. After calcination of the aluminum sulfate with addition of 0.1 wt% Fe₂O₃at 1200℃, the formation of FeAl₂O₄spinel prohibited the γ→αtransformation of the alumina. However, the addition of > 0.1 wt% Fe₂O₃and the increase in calcination temperature to 1300℃ accelerated the γ→αtransformation, due to the decomposition of FeAl₂O₄to α-Al₂O₃and Fe₂O₃and the velocity of ion diffusion, respectively.

2003학년도 조선대학교 신입생 특성 분석

류찬수,원효성,박근영 朝鮮大學校 學生生活硏究所 2004 生活指導硏究 Vol.23 No.1

다단계 수리체계의 성능평가를 위한 폐쇄형 대기행렬 네트워크 모형

박찬우,김창곤,이효성 한국경영과학회 2000 한국경영과학회지 Vol.25 No.4

In this study we consider a spares provisioning problem for repairable items in which a parts inventory system is incorporated. If a machine fails, a replacement part must be obtained at the parts inventory system before the failed machine enters the repair center. The inventory policy adopted at the parts inventory system is the (S,Q) policy. Operating times of the machine before failure, order in lead times and repair times are assumed to follow a two-stage Coxian distribution. For this system, we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of machines at each station and they probability that a part will wait at the parts inventory system. For the analysis of the proposed system, we model the system as a closed queueing network and analyze it using a product-form approximation method. A recursive technique as well as an iterative procedure is used to analyze the sub-network. Numerical tests show that the approximation method provides fairly good estimation of the performance measure of interest.

하지 중량부하 걷기 운동이 비만 청소년의 신체조성에 미치는 영향

김효찬 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.4

The purpose of this study is to know about the influence of the lower limbs-weight walking exercise on body composition in obese youth For this study, 35 obese students were selected who volunteered in an attempt this case study from D high school in Incheon city and they are all have more than 25% of BMI(㎏/㎡). These students are randomly classified to 3 groups as like; 1) Group with 12 members who they dont exercise at all, 2) Group with 11 members who they do walking exercise, 3) Group with 12 members who they do lower limbs-weight walking exercise. For examine closely into the lower limbs-weight walking exercise, took an accurate measurement of body composition after taking 12 weeks treadmill exercise. To verify of the average values difference before and after walking exercise, I did Paired t-test. And, used One-way ANOVA for whether or not these 3 groups difference. Here are the results from this case study. (1) There is a difference between all groups with the weight from 12 weeks exercise, but no difference with the weight of 2 walking exercise groups. (2) There is no difference after 12 weeks exercise with the body at between the groups, there is more decline of the lower limbs-weight walking exercise group than others. (3) There is no difference between 3 groups with the body at before exercising, however, slight difference can be shown after 12 weeks exercise. Arid, there is more decline founded of the lower limbs-weight walking exercise group than other groups. (4) There is no difference between 3 groups with the breast at before exercise, but after 12 weeks exercise, slight difference can be founded. And, there is more decline founded of the lower limbs-weight walking exercise group than others. (5) There is no difference between groups with the abdomen at before exercising, however, there is a slight difference after 12 weeks exercise. There is more decline founded of the lower limbs-weight walking exercise group. (6) There is a difference between all groups with the thigh fat. However, it can be more declined of the lower limbs-weight walking exercise group than other groups.