• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.88-91
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• 2005

The combustion characteristics of high burning HTPB/AP solid propellants have been investigated by means of a closed bomb method of interval volume of 200 co and 700 cc at pressures from 1000 to 30,000 psi. The burning rate data measured by closed bomb are in good agreement with strand burner test results at pressure from 1000 to 5000 psi using disc sample of 1 mm thickness. The burning rate dat by using 200 cc closed bomb are in general agreement with that of 700 cc closed bomb. At pressure between $5,000\sim7,000$ psi, a market increase in pressure dependence of the linear burning rate occurs for HTPB/AP propellant.

• Journal of KIISE:Software and Applications
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• v.30 no.9
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• pp.885-893
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• 2003

In this paper, a new practical implementation of a person verification system using features of longitudinal section and transection and other facial, rotation compensated 3D face image, is proposed. The approach works by finding the nose tip that has a protrusion shape on the face. In feature recognition of 3D face image, one has to take into consideration the orientated frontal posture to normalize. Next, the special points in regions, such as nose, eyes and mouth are detected. The depth of nose, the area of nose and the volume of nose based both on the 3 longitudinal section and a transection are calculated. The eye interval and mouth width are also computed. Finally, the 12 features on the face were extracted. The Ll measure for comparing two feature vectors were used, because it is simple and robust. In the experimental results, proposed method achieves recognition rate of 95.5% for the longitudinal section and transection.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.49-49
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• 2003

목적 : 심초음파는 비침습적이므로 반복적으로 정확히 심질환의 경과를 관찰하여 치료효과 및 수술시기를 정할 수 있는 검사로서 임상적으로 매우 유용하다. 실시간 심근조영심초음파에 의한 time intensity 평가는 부위별로 수행됨으로 연속적으로 위치하는 관심영역이 intensity에 있어 심장의 움직임 변화에 영향을 받는다. Time intensity 곡선의 최적의 곡선맞춤을 위해 주기적인 심장 운동 매개변수를 조합해 기존의 모델을 보정한 안정적인 측정방법을 제시한다. 방법 : 심장의 운동에 의한 특징적인 정보를 설명하기 위해 기존의 문헌에 제시된 지수 함수에 주어진 심박수로 만들어진 시간에 관한 일반적인 정형파 함수를 추가한다. C(t) = A[1 - exp($\beta$t)] + Dsine(2$\pi$ft + $\theta$) C(t): videointensity A: plateau videointensity (blood volume) $\beta$: capillary blood velocity (rate constant of rise in videointensity) t: pulsing interval (ms) D: displacement from the periodic variance of the curve (estimated motion field from the ejection point for the ratio between systole and diastole) f: heart rate $\theta$: transit time issue A $\times$ $\beta$ : myocardial blood flow 관상동맥의 관류 데이터에 대한 실험이 펄스간격에 대한 비디오 세기로 수행되었다. 그리고 이러한 결과들이 the sum of squares due to error, R square, root mean squared error로 평가되었다. 결과 : 실험결과, 주기적인 심장의 움직임과 심박출 시점으로부터의 변위를 잘 기술하고 곡선에서의 측정 점들이 예측된 심장 움직임에 따라 성공적으로 표시되었다. 뿐만 아니라 보정된 모델이 현저한 적합도의 향상을 보여주었다. 결론 : 제시된 접근방법은 각각의 측정에서 심장 운동 영역의 변화에 독립적이며 측정 시점에 의해 영향받지 않고 심근 관류의 안정적인 측정이 가능하다. 심장의 움직임에 관한 매개변수를 조합한 모델로 곡선접합을 수행함으로써 관류의 정량적 정보를 좀더 정확하게 얻을 수 있으며 임상적 이용을 가능하게 할 것으로 기대된다.

• The Journal of Internal Korean Medicine
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• v.23 no.2
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• pp.274-279
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• 2002

The sick sinus syndrome refers to a combination of symptoms (dizziness, confusion, fatigue, syncope, and congestive heart failure) caused by sinus node dysfunction and marked sinus bradycardia, sinoarterial block, or sinus arrest. 'Abdominal pulsation' means a disagreeable symptom that is defined as sensation of beating at the abdomen. We experienced a 84 year-old female patient who had dizziness, fatigue, abdominal pulsation and frequent voiding. These symptoms were related to previous episodes and presumed sick sinus syndrome by symptoms, ECGs and 24 hrs of holter monitoring. In the point of Differentiation of Syndrome (辨證), this patient was diagnosed as 'Water retention(水氣)' and was administered with Yeonggyechulgam-tang(岺桂朮甘湯). After the treatment, abdominal pulsation (frequency) and dizziness (VAS) were improved. Futhermore, the interval of voiding was longer and each volume of urination increased.

• Journal of Korean Society of Transportation
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• v.19 no.3
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• pp.75-88
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• 2001

Signal optimization model for alternative use of lanes at a signalized intersection with an stop-line added backward was presented in this paper. The simulation results shot-ed that the traffic fed from the stop-line passed the intersection in each specified phasing interval for left and through traffic. The experimental results indicated that the proposed model was much superior to traditional signal optimization methodology in reducing delay, fuel consumption, and disutility index for delay and stops. The effects for reducing delay were greater than those for doing fuel consumption and disutility index due to the added stop-line. The proposed model is expected to alleviate traffic congestion at intersections, both which have no left turn pocket, and which have large left turn volume. The model is recommended to adapted for intersections spaced long among them with no near driveway.

• Journal of Korean Neurosurgical Society
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• v.56 no.2
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• pp.86-90
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• 2014

Objective : The spot sign is related with the risk of hematoma expansion in spontaneous intracerebral hemorrhage (ICH). However, not all spot sign positive patients undergo hematoma expansion. Thus, the present study investigates the specific factors enhancing the spot sign positivity in predicting hematoma expansion. Methods : We retrospectively studied 316 consecutive patients who presented between March 2009 to March 2011 with primary ICH and whose initial computed tomography brain angiography (CTA) was performed at our Emergency Department. Of these patients, 47 primary ICH patients presented spot signs in their CTA. We classified these 47 patients into two groups based on the presence of hematoma expansion then analyzed them with the following factors : gender, age, initial systolic blood pressure, history of anti-platelet therapy, volume and location of hematoma, time interval from symptom onset to initial CTA, spot sign number, axial dimension, and Hounsfield Unit (HU) of spot signs. Results : Of the 47 spot sign positive patients, hematoma expansion occurred in 26 patients (55.3%) while the remaining 21 (44.7%) showed no expansion. The time intervals from symptom onset to initial CTA were $2.42{\pm}1.24$ hours and $3.69{\pm}2.57$ hours for expansion and no expansion, respectively (p=0.031). The HU of spot signs were $192.12{\pm}45.97$ and $151.10{\pm}25.14$ for expansion and no expansion, respectively (p=0.001). Conclusions : The conditions of shorter time from symptom onset to initial CTA and higher HU of spot signs are the emphasizing factors for predicting hematoma expansion in spot sign positive patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.222-229
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• 2009

This study presents comparison of heat transfer and air side friction characteristics in a condenser condition of air conditioner between Louver fin-tube heat exchangers and aluminum parallel heat exchangers. All experiments are performed using an air-enthalpy type calorimeter, which is designed based on the method described in ASHRAE standards. The air velocities crossing the heat exchanger tubes are varied from 0.7 to 1.6 m/s with 0.3 m/s interval, maintaining air dry temperature and relative humidity at $20^{\circ}C$ and 60% respectively. Water temperature and flow rate inside the tube are $70^{\circ}C$ and 10 LPM, respectively. Experimental results show that the heat transfer performances of aluminum heat exchangers are 17-163% higher than those of Louver fin-tube heat exchangers based on the data per unit volume, mass, and heat transfer area, whereas air side pressure drops of aluminum heat exchangers are 19-81% lower.

• Clinical and Experimental Pediatrics
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• v.53 no.11
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• pp.951-956
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• 2010

Purpose: To compare the profiles of the bronchodilator response (BDR) among children with asthma and/or allergic rhinitis (AR) and to determine whether BDR in these children is reduced by treatment with inhaled and/or nasal corticosteroid. Methods: Sixty-eight children with asthma (mean age, 10.9 years), 45 children with comorbid asthma and AR (mean age, 10.5 years), and 44 children with AR alone (mean age, 10.2 years) were investigated. After a 2-week baseline period, all children were treated with inhaled fluticasone propionate (either 100 or $250{\mu}g$ b.i.d., tailored to asthma severity) or nasal fluticasone propionate (one spray b.i.d. in each nostril) or both, according to the condition. Before and 2 weeks after starting treatment, all children were evaluated with spirometry and bronchodilator testing. BDR was calculated as a percent change from the forced expiratory volume in 1 second ($FEV_1$) at baseline. Results: The mean BDR was 10.3% [95% confidence interval (CI) 8.3-12.4%] in children with asthma, 9.0% (95% CI 7.3-10.9%) in subjects with asthma and AR, and 5.0% (95% CI 4.1-5.9%) in children with AR alone ($P$<0.001). After treatment, the mean BDR was reduced to 5.2% (95% CI 4.2-6.3%) ($P$<0.001) in children with asthma and to 4.5% (95% CI 3.5-5.5%) ($P$<0.001) in children with asthma and AR. However, children with rhinitis showed no significant change in BDR after treatment, with the mean value being 4.7% (95% CI 3.7-5.8%) ($P$=0.597). Conclusion: The findings of this study imply that an elevated BDR in children with AR cannot be attributed to nasal inflammation alone and highlights the close relationship between the upper and lower airways.

• Journal of the Korean Operations Research and Management Science Society
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• v.3 no.1
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• pp.31-46
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• 1978

Consider a time interval during which the demand for trips is fixed (e.g. the rush hour period). The traveller has a choice between various public modes, whose travel times and fares are fixed, and the automobile mode, for which travel time and cost depend on the volume of traffic flow on those roads, which are subject to congestion. We consider the equilibrium in terms of a representative travellerm, who choses for any trip the mode and route with the least combined money and time cost. When several (parallel) model or routes are chosen, then the combined cost of money and time must be equal among these. Our problem is first, to find the optimal flows of cars and of public mode carriers on the various links of their networks and second the optimal fares for trips by the variousmodes. The object is to minimize the total operating costs of the carriers and car plus the total time costs to travellers. The optimal fares are related to, but not identical with the dual variables of the underlying Nonlinear Program. They are equal to these dual variables only in the case, when congestion tolls on trips or on the use of specific roads are collected from automobile users. When such tolls are not collected, they must be passed on as subsidies to travellers using competing modes. The optimal fares of public modes are then reduced by the amounts of these subsidies. Note that subsidies are not a flat payment to public carriers, but are calculated on the basis of tickets sold. Fares and subsidies depend in general on tile period considered. They will be higher during periods of higher demand. When the assumption of fixed trip demand is relaxed, this tare system is no longer best, but only second best since too much traffic will, in general, be generated. The Free Rider Theorem states the following : Suppose road tolls can be charged, so that a best pricing system for public modes is posssible. Then there may exist free rides on some routes and modes, but never on a complete round trip.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.137-148
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• 2005

The position information of individual vehicles on a road at every time instant can be used to analyze the microscopic behaviors of driving of each vehicle. The limited information obtained from previous imaging technology such as traffic volume and interval velocity cannot be used to explore such microscopic traffic conditions. Also, information gathering for the microscopic behaviors by manual analysis of captured video takes large amount of time and man-power. In the paper we develop the rule-based vehicle tracking technology from which the position information of individual vehicles on a road at every time instant can be automatically obtained. Also, we extract the position data of driving vehicles on a road, length of 130m for every 0.05 second, and calculate the velocity of each traced vehicles to compare with the real velocity for the verification of accuracy. In the future, this type of tracking techniques based on video analysis can be widely used to provide the practically important information of road traffic conditions and to analyze the academically important microscopic behaviors of driving patterns.