• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.4
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• pp.63-75
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• 2018

A Service Area plays an important role in preventing accidents in advance by creating a space for long distance drivers or drowsy drivers to rest. Therefore, proper positioning of the expressway service area is essential, and it is important to analyze accurate demand forecasting and user travel behavior. Thus, this study analysis travel behavior and developed odel of the probability of using the service area by using the DSRC data collected by the RSE on the highway. According to the analysis, the usage behavior of highway service areas was most frequently when travel time was 90 minutes or more on weekdays and 70 minutes or more on weekends. The utilization rate of the service area estimated from the probability model of use of the rest area in this study was 1 % to 2 % error. The results of this study are meaningful in analyzing the behavior of the use of rest areas using the structured data and can be used as a differentiated strategy for selecting the location of rest areas and enhancing the service level of users.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.4
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• pp.589-598
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• 2000

A pilot-scale Spray Drying Sorber (SDS) system was set up to evaluate the effect of spray characteristics on the desulfurization yield. The size distribution and the Sauter Mean Diameters of slurry droplets were measured in advance using the optical size measurement system, Malvern 2600. The desulfurization yield of the drying chamber by size was measured for the conditions of inlet gas and spray injection. As a reagent, 10% limestone slurry of $Ca(OH)_2$ was treated with flue gas containing $SO_2$, and the combustion gas analyzer and gas detectors were attached to measure the $SO_2$ concentration. With a flow rate of 144 Nm3/h and a temperature range of $200{\sim}300^{\circ}C$, the experiments were performed for the Stoichiometric Ratio (SR) of 1.0 to 3.0 and droplet mean diameter of 6.5 to $34.3{\mu}m$. In case of smaller spray droplets, the desulfurization efficiency improved due to the increase of total droplet surface area, while the reduction in evaporation time reduced the contact time between the droplets and $SO_2$ gas. In some typical region of droplet diameter, this negative effect, reduction of contact time, became dominant and the desulfurization yield decreases the desulfurization yield in spite of the expansion in absorption area. These results revealed that there exists the optimal size of spray droplets for a given state, which is determined by the compromise between the total surface area of slurry droplets and the evaporation time of droplets. The measurements also indicated that the inlet temperature of flue gas changes the optimal injection condition by varying the driving force for evaporation. The results confirm that the effect of the evaporation time of slurry droplets should be considered in analyzing the desulfurization yield as well as the total surface area, for it is a significant aspect of the correlation with the capabilities of $SO_2$ absorption in wet droplets. In conclusion, the optimal condition of spray can be determined based on these results, which might be applied to design or scale-up of SDS system.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.314-317
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• 2002

The purpose of this study was to evaluate the clinical application of Patlak tool on GE PET workstation for quantitative analysis of dynamic PET images in cardiac patients. Three patients including coronary artery disease (CAD), myocardial infarction (MI), and angina were studied. All subjects underwent dynamic cardiac PET scan using a GE Advance scanner. After 10 min transmission scan for attenuation correction using two rotating $\^$68/Ge rod sources, three patients with cardiac disease were performed dynamic cardiac PET scan after the administration of approximately 370 MBq of FDG. The dynamic scan consisted of 36 frames with variable frame length (12${\times}$10s, 6${\times}$20s, 6${\times}$60s, 12${\times}$300s) for a total time of 70 min. Blood samples were obtained to determine the plasma substrate concentration. Region of interest of circular and rectangular shape to acquire input functions and tissue data were placed on left ventricle and myocardium. A value of 0.67 was used for lumped constant. Mean plasma substrate concentrations for three patients were 100 mg/dl (CAD), 100 mg/dl (MI), 132 mg/dl (angina), respectively. Regional MMRGlc values (mean${\pm}$SD) at lateral myocardium area for CAD, MI, and angina were 8.43${\pm}$0.24, 4.08${\pm}$0.16, and 6.15${\pm}$0.23 mg/min/100ml, respectively. Patlak tool on GE PET workstation appeared to be useful for quantitative analysis of dynamic PET images in cardiac patients, although further studies may be required for absolute quantitation.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.147-153
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• 2011

In this paper, we present a new video management technique using forward timeline to efficiently store and delete the videos on a local server. The proposed method is based on capturing the changing preference of the videos according to recentness, frequency, and playback length of the requested videos. For this purpose, we utilize the forward timeline which represents the time area within a number of predefined intervals. The local server periodically measures time popularity and request segment of all videos. Based on the measured data, time popularity and request segment, the local server calculates the mean time popularity and mean request segment of a video using forward timeline. Using mean time popularity and mean request segment of video, we estimate the ranking and allocated storage space of a video. The ranking represents the priority of deletion when the storage area of local server is running out of space and the allocated storage space means the maximum size of storage space to be allocated to a video. In addition, we propose an efficient storage space partitioning technique in order to stably store videos and present a time based free-up storage space technique using the expected variation of video data in order for avoiding the overflow on a local server in advance. The simulation results show that the proposed method performs better than other methods in terms of hit rate and number of deletion. Therefore, our video management technique for local server provides the lowest user start-up latency and the highest bandwidth saving significantly.

• Journal of radiological science and technology
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• v.5 no.1
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• pp.77-95
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• 1982

The result of this study from surveying and analyzing the present situation of educational institutes of radiologic technology, educational situation of radiologic technology, and students' attitude and recognition about the education of radiologic technology, the faculty's thought of it throughout the country from October, 1981 to April, 1982 is as follows: 1. The total number of educational institutes for radiologic technology is 11, but all of them are private colleges classified by foundation and 1,414 freshmen were admitted to enter the colleges by admission quotas of students at present in March, 1982. 2. The number of male(1965-1982) is 3,046(78.0%), that of female is 856(22.0%), and total of them is 3,904 that graduated from the departments of radiologic technology in 9 junior colleges in Korea. 3. The number of the instructional staffs in radiologic technology in Korea is 32, but among them 1 professor, 1 associate professor, 16 assistant professors and 14 full-time instructors. 4. The credits for graduation are 80-96 credits and students need required liberal arts and required major studies to get the qualification for graduation. 5. In the national examination for radio-technologist license, total 7,150 persons took the examination, but only 2,796 persons passed it, therefore, the average passed rate is 39.1% from the year 1965 to 1982. 6. 61.3% of students expressed dissatisfaction about their campus lives, the reason of which is mainly poor educational facilities(26.7%), insufficient number of faculty(21.2%) and negative Recognition on junior college from society, etc. 7. About the education of their major studies of colleges, 70.9% of students answered that they were short of laboratory works and clinical trainings rather than theoretical lessons. 8. The chief problem in practice works is about facilities and equipemtns for practice (students 39.1%, faculty 68.8%), and about the fact that too many students usually work at a time(students 17.1%, faculty 21.9%), etc. 9. 87.4% of students and 93.8% of faculty answered that clinical training in school is necessary. 10. Students' viewpoints on the radiologic technologist and the attitudes on the profession as a radiologic technologist are approximately affirmative. 11. Fields of employment to advance after graduation are mainly the fields related to their major studies(hospital, clinic, health clinic, industrial companies related and military officers of medical technology, etc.), which fields arc predominant to 74.5% rather than non-related fields(enrols into 4 year colleges, etc.). 12. 85.2% of students, 87.5% of the faculty expressed their opinions that the present academic years of 2 should be lengthened more. 13. 90.7% of the faculty expressed their opinions that the present students quotas should be reduced in whole or in part.

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.468-473
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• 1993

Background: Recent advance in video technology, endoscopic equipments, and surgical techniques have expanded the use of thoracoscopy from diagnosis of the pleural diseases to treatment of the various intrathoracic diseases. Video Assisted Thoracoscopic Surgery(VATS) is a pretty new and fascinating thoracic surgical modality, and so we present our early VATS resuls. Methods: Using Video Thoracoscopic techniques in 30 patients for 10 months from July 1992 to April 1993, we had performed a variety of procedures. These incuded (1) bleb resections in 18 patients (19 cases), (2) mediastinal tumor excision in 4, (3) lung biopsies for parenchymal pulmonary disease in 3, (4) pleural biopasies in 3, (5) pleural tumor excision in 1, (6) and pleuropericardial window in 1. Results: There were no mortality associated with the procedures. We had minor 8 complications; prolonged air leak in 3 patients, prolonged serous drainage in 2, recurrence of pneumothorax in 1, Honer's syndrome in 1, and hoarseness in 1 patient. None of the 30 patients had reverted to the conventional full thoracotomies. Mean postoperative hospital stay of non-complicated pneumothoraces was about 5 days, which was a little shorter than conventional thoracotomy group. Conclusion: Though we had somewhat higher postoperative complication rate due to lack of experiences in the begining, we were able to convince that VATS had benifical value for patients; lesser postoperative pain, shorter hospitalization, quicker recovery time, and cosmetically superior scar. The role of VATS can be expanded to the diagnosis and treatment of various thoracic diseases, even to the cardiovascular diseases, with satisfactory outcome and less postoperative morbidity.

• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.95-107
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• 2004

In this paper, the rheological characteristics of slurry used fur slurry-shield tunnels were studied with emphasis on penetration characteristics. The slurry penetration was modeled by soil-filter clogging theory. The coefficient of particle deposition was suggested as an indicator of sin clogging during tunnel construction and calculated through model tests. The measured slurry weight, clogged in the base soil, was compared with the value obtained from clogging theory. Based on the testing results, a stability analysis of a tunnel face was performed to pinpoint the most influential factor affecting stability of slurry-shield tunnels. It was found that the stability of tunnel face is dependent on the ratio of infiltration velocity to the coefficient of particle deposition, and the penetration distance of slurry increases with the ratio of infiltration velocity to the coefficient of particle deposition. Since the stability of tunnel face decreases with the slurry penetration distance, it was necessary to add some additives in order to reduce the slurry penetration distance. It was found that the ground condition needs additives when the soil has the effective particle diameter$(D_{10})$ larger than 0.75mm. It was also found that the tunnel face stability due to slurry penetration is significantly affected by the tunnel advance rate.

• Journal of the Korean GEO-environmental Society
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• v.15 no.9
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• pp.77-85
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• 2014

Recently, the National Emergency Management Agency of Korea has been operating the National Disaster Management System. Nevertheless, there are numerous difficulties in systematic controlling the steep slope DB promptly, because the system's functions in input and control for steep slope information are merely simple. Futhermore, the hazard degrees of steep slope lands nowadays have risen suddenly in accordance with the increase rate of large scale landslides such as the landslide cases of Umyeonmountain, Chuncheon province and others or sever rain storm cases. these lead to rapid increases in frequencies of nature disasters nationally. therefore, it is needed to develop the GIS-based integrated management system for steep slope information in order to manage disasters in advance or high-degree control. This study shows the national GIS-based integrated management system to prevent the disasters that caused by steep slope lands. The integrated management system developed in this study consists of surface information input modules, realtime DB liaison modules of integrated underground information, V-world background map-based GIS, integrated management system for steep slope information user modules, realtime liaison interface modules designed for utilizing steep slope information. Also, tests about stability of data storage, system stability and consistency of processing speed were performed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.9005-9008
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• 2014

Background: Gastric cancer is the second leading course of cancer death worldwide and H. pylori infection is an important risk factor for gastric cancer development. This study was design to evaluate the clinical, pathological features, survival rate and prevalence of H. pylori infection in gastric cancer in Thailand. Materials and Methods: Clinical information, histological features, endoscopic findings and H. pylori status were collected from gastric cancer patients from Thammasat university hospital during June 1996-December 2011. H. pylori infection was assessed by histological evaluation, rapid urease test and serological test. Clinical information, endoscopic findings and histopathology of all patients were recorded and compared between patients with active or non-active H. pylori infection. Results: A total of 100 gastric cancer patients (55 men and 45 women with mean age of $55{\pm}16.8years$) were enrolled in this study. Common presenting symptoms were dyspepsia (74%), weight loss (66%), anemia (63%) and anorexia (38%). Mean duration of symptoms prior to diagnosis was 98 days. Overall prevalence of H. pylori infection was 83% and active H. pylori infection was 40%. 1-year and 5-year survival rates were 43% and 0%. There was no significant difference between active H. pylori infection in different locations (proximal vs non-proximal: 47.1% vs 48.5%; P-value = 0.9, OR=0.9; 95%CI=0.3-3.1) and histology of gastric cancer (diffuse type vs intestinal type: 47.4% vs 50%; P-value = 0.8, OR=0.9, 95%CI=0.3-2.7). However, linitis plastica was significantly more common in non-active than active H. pylori infection (27.9% vs 0%; P-value<0.0001, OR=13.3, 95%CI=3.2-64.5). Moreover, gastric cancer stage 4 was higher in non-active than active H. pylori infection (93% vs 50%, P-value<0.001). Conclusions: Prevalence of H. pylori infection in Thai gastric cancer patients was high but active infection was low. Most gastric cancer patients presented in advance stage and had a grave prognosis. Screening for gastric cancer in high risk individuals might be an appropriate tool for early detection and improve the treatment outcome for this particular disease in Thailand.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.271-278
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• 2014

In spite of that stop line and crosswalk should be aware of the most basic objects in transportation system, its features extracted are very limited. In addition to image-based recognition technology, laser and RF, GPS/INS recognition technology, it is difficult to recognize. For this reason, the limited research in this area has been done. In this paper, the algorithm to recognize the stop line and crosswalk is designed and implemented using image-based recognition technology with the images input through a vision sensor. This algorithm consists of three functions.; One is to select the area, in advance, needed for feature extraction in order to speed up the data processing, 'Region of Interest', another is to process the images only that white color is detected more than a certain proportion in order to remove the unnecessary operation, 'Color Pattern Inspection', the other is 'Feature Extraction and Recognition', which is to extract the edge features and compare this to the previously-modeled one to identify the stop line and crosswalk. For this, especially by using case based feature comparison algorithm, it can identify either both stop line and crosswalk exist or just one exists. Also the proposed algorithm is to develop existing researches by comparing and analysing effect of in-vehicle camera installation and changes in recognition rate of distance estimation and various constraints such as backlight and shadow.