• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.133-150
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• 1996

This study is to clarify the market cycle of travelling merchants and the spatial behavior of consumer's commodity purchasing. its reasons and purchasing region of each commodity in Chongsan of Chongsan Myun(village) periodic markets, that is one of the lowest central places in Okchon county. The data used are the results of interviews with 58 travelling merchants on June 22 and July 17, 1994, and questionaire survey taken to parents of students of Chongsan middle school of Chongsan Myun in Okchon county. Study area is typical agricultural regions taking the role of central places to provide rural service and is comparatively important periodic markets. Some of findings are summarized as follows: (1) Until 1980's. appearance of closed periodic markets is caused by the population decrease in rural region, income increase, and rising of living level according to the Five Years Planning of Economic Development, appearance of chain stores of agricultural co-coperative and of supermarkets,. changes in distribution mechanisim by increasing consignment volume of agricultural products through agricultural co-coperative, and the development of transportation in Okchon county. These, too, became the reasons for the decline of the Chongsan periodic markets in Okchon county. (2) Most of the travelling merchants visiting the Chongsan periodic markets are in their 50's of age, and they sell the miscellaneous commodities and agricultural products. And about one-fourths of travelling merchants reside in regions with periodic markets and in Okchon of higher order central places. (3) Travelling routes visting periodic markets can be simplified to five types. Major types of travelling routes are Chongsan periodic market$\rightarrow$Wonnam$\rightarrow$Boun, and Chongsan periodic market$\rightarrow$Yungdong$\rightarrow$Yongsan. The patterns of travelling merchants visiting periodic markets are classified into the type of everyday visiting of periodic markets over three days of five days from merchant's residence to market, and the type of merchants or consumers visiting one day's of five days. On days that travelling merchants don't visit periodic markets they purchase the commodities in Seoul, Taejon and Chongju. (4) Consumers who use periodic markets are from thirties to fifties years of age and most of them are employed in agriculture. Consumers visit periodic markets on foot or by bus, and visit two or three times in a month, and mainly purchase the commodities for one or two hours from about ten o'clock in the morning. (5) Consumers purchase the necessaries of life in periodic markets, and other commodities are purchased in Taejon city, Youngdong, and Boun Eup(town). But consumers purchase the goods(convenience goods, shopping goods, and specialied goods) largerly in Chongsan, because additional expense and disadvantage after service with poor transportation service for purchased goods in others regions. Therefore, the hierarchies of central places by the consumer's purchasing behaviour can not be seem in dewellers in Chongsan and Chongseong Myun.

• Journal of Intelligence and Information Systems
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• v.17 no.2
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• pp.39-60
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• 2011

Since the introduction of web 2.0 technology, social network service has been recognized as the foundation of an important future information technology. The advent of web 2.0 has led to the change of content creators. In the existing web, content creators are service providers, whereas they have changed into service users in the recent web. Users share experiences with other users improving contents quality, thereby it has increased the importance of social network. As a result, diverse forms of social network service have been emerged from relations and experiences of users. Social network is a network to construct and express social relations among people who share interests and activities. Today's social network service has not merely confined itself to showing user interactions, but it has also developed into a level in which content generation and evaluation are interacting with each other. As the volume of contents generated from social network service and the number of connections between users have drastically increased, the social network extraction method becomes more complicated. Consequently the following problems for the social network extraction arise. First problem lies in insufficiency of representational power of object in the social network. Second problem is incapability of expressional power in the diverse connections among users. Third problem is the difficulty of creating dynamic change in the social network due to change in user interests. And lastly, lack of method capable of integrating and processing data efficiently in the heterogeneous distributed computing environment. The first and last problems can be solved by using FOAF, a tool for describing ontology-based user profiles for construction of social network. However, solving second and third problems require a novel technology to reflect dynamic change of user interests and relations. In this paper, we propose a novel method to overcome the above problems of existing social network extraction method by applying FOAF (a tool for describing user profiles) and RSS (a literary web work publishing mechanism) to OLAP system in order to dynamically innovate and manage FOAF. We employed data interoperability which is an important characteristic of FOAF in this paper. Next we used RSS to reflect such changes as time flow and user interests. RSS, a tool for literary web work, provides standard vocabulary for distribution at web sites and contents in the form of RDF/XML. In this paper, we collect personal information and relations of users by utilizing FOAF. We also collect user contents by utilizing RSS. Finally, collected data is inserted into the database by star schema. The system we proposed in this paper generates OLAP cube using data in the database. 'Dynamic FOAF Management Algorithm' processes generated OLAP cube. Dynamic FOAF Management Algorithm consists of two functions: one is find_id_interest() and the other is find_relation (). Find_id_interest() is used to extract user interests during the input period, and find-relation() extracts users matching user interests. Finally, the proposed system reconstructs FOAF by reflecting extracted relationships and interests of users. For the justification of the suggested idea, we showed the implemented result together with its analysis. We used C# language and MS-SQL database, and input FOAF and RSS as data collected from livejournal.com. The implemented result shows that foaf : interest of users has reached an average of 19 percent increase for four weeks. In proportion to the increased foaf : interest change, the number of foaf : knows of users has grown an average of 9 percent for four weeks. As we use FOAF and RSS as basic data which have a wide support in web 2.0 and social network service, we have a definite advantage in utilizing user data distributed in the diverse web sites and services regardless of language and types of computer. By using suggested method in this paper, we can provide better services coping with the rapid change of user interests with the automatic application of FOAF.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.19-26
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• 2017

Purpose: The application of density override is very important to minimize dose calculation errors by fiducial markers of metal material in proton treatment plan. However, density override with actual material of the fiducial marker could make problem such as inaccurate target contouring and compensator fabrication. Therefore, we perform density override with surrounding material instead of actual material and we intend to evaluate the usefulness of density override with surrounding material of the fiducial marker by analyzing the dose distribution according to the position, material of the fiducial marker and number of beams. Materials and Method: We supposed that the fiducial marker of gold, steel, titanium is located in 1.5, 2.5, 4.0, 6.0 cm from the proton beam's end of range using water phantom. Treatment plans were created by applying density override with the surrounding material and actual material of the fiducial marker. Also, a liver cancer patient who received proton therapy was selected. We located the fiducial marker of gold, steel, titanium in 0, 1.5, 3.5 cm from the proton beam's end of range and the treatment plans were created by same method with water phantom. Homogeneity Index(HI), Conformity Index(CI) and maximum dose of Organ At Risk(OAR) in Planning Target Volume(PTV) as the evaluation index were compared according to the material, position of the fiducial marker and number of beam. Results: The HI value was more decreased when density override with surrounding material of the fiducial marker was performed comparing with density override with actual material. Especially the HI value was increased when the fiducial marker was located farther from the proton beam's end of the range for a single beam and the fiducial marker's position was closer to isocenter for two or more beams. The CI value was close to 1 and OAR maximum dose was greatly reduced when density override with surrounding material of the fiducial marker was performed comparing with density override with actual material. Conclusion: Density override with surrounding material can be expected to achieve more precise proton therapy than density override with actual material of the fiducial marker and could increase the dose uniformity and target coverage and reduce the dose to surrounding normal tissues for the small fiducial markers used in clinical practice. Most of all, it is desirable to plan the treatment by avoiding the fiducial marker of metal material as much as possible. However, if the fiducial marker have on the beam path, density override of the surrounding material can be expected to achieve more precise proton therapy.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.575-583
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• 2017

Germination is a well-known economical technique that has been utilized to enhance the nutritional value of brown rice. Owing to its higher nutritive quality, germinated brown rice has received significant attention in the past decade. In this study, the physicochemical and cooking properties of specialty brown rice (SBR) were analyzed before and after germination. Germination enhanced cooking properties such as water absorption, expanded volume, and increased solid solubility of cooked SBR. The SBR texture measured using tensipresser, was significantly improved by germination. The hardness of cooked SBR was decreased by germination, but stickiness was increased. Pasting analysis of the SBR flours revealed a decrease in all viscosity values (peak viscosity, breakdown, setback, and final viscosity) after germination. However, the gelatinization temperature remains unchanged upon germination. Additionally, amylose content and amylopectin chain length distribution of SBR starch were slightly changed by germination. These results indicate that germination leads to a substantial improvement in the cooking properties and texture of SBR.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.213-230
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• 2008

The aim of this study was to analyze the initial movement and the stress distribution of each tooth and periodontal ligament during the lingual lever-arm retraction of 6 maxillary incisors using FEA. Two kinds of finite element models were produced: 2-properties model (simple model) and 24-properties model (multi model) according to the material property assignment. The subject was an adult male of 23 years old. The DICOM images through the CT of the patient were converted into the 3D image model of a skull using the Mimics (version 10.11, Materialise's interactive Medical Image Control System, Materialise, Belgium). After series of calculating, remeshing, exporting, importing process and volume mesh process was performed, FEA models were produced. FEA models are consisted of maxilla, maxillary central incisor, lateral incisor, canine, periodontal ligaments and lingual traction arm. The boundary conditions fixed the movements of posterior, sagittal and upper part of the model to the directions of X, Y, Z axis respectively. The model was set to be symmetrical to X axis. Through the center of resistance of maxilla complex, a retraction force of 200g was applied horizontally to the occlusal plane. Under this conditions, the initial movements and stress distributions were evaluated by 3D FEA. In the result, the amount of posterior movement was larger in the multi model than in the simple model as well as the amount of vertically rotation. The pattern of the posterior movement in the central incisors and lateral incisors was controlled tipping movement, and the amount was larger than in the canine. But the amount of root movement of the canine was larger than others. The incisor rotated downwardly and the canines upwardly around contact points of lateral incisor and canine in the both models. The values of stress are similar in the both simple and multi model.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.360-373
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• 2017

The BTO-a projects is the types, which has a demand risk among the type of PPP projects in Korea. When demand risk is realized, private investor encounters financial difficulties due to lower revenue than its expectation and the government may also have a problem in stable infrastructure operation. In this regards, the government has applied various risk sharing policies in response to demand risk. However, the amount of government's risk sharing is the government's contingent liabilities as a result of demand uncertainty, and it fails to be quantified by the conventional NPV method of expressing in the text of the concession agreement. The purpose of this study is to estimate the value of investment risk sharing by the government considering the demand risk in the profit sharing system (BTO-a) introduced in 2015 as one of the demand risk sharing policy. The investment risk sharing will take the form of options in finance. Private investors have the right to claim subsidies from the government when their revenue declines, while the government has the obligation to pay subsidies under certain conditions. In this study, we have established a methodology for estimating the value of investment risk sharing by using the Black - Scholes option pricing model and examined the appropriateness of the results through case studies. As a result of the analysis, the value of investment risk sharing is estimated to be 12 billion won, which is about 4% of the investment cost of the private investment. In other words, it can be seen that the government will invest 12 billion won in financial support by sharing the investment risk. The option value when assuming the traffic volume risk as a random variable from the case studies is derived as an average of 12.2 billion won and a standard deviation of 3.67 billion won. As a result of the cumulative distribution, the option value of the 90% probability interval will be determined within the range of 6.9 to 18.8 billion won. The method proposed in this study is expected to help government and private investors understand the better risk analysis and economic value of better for investment risk sharing under the uncertainty of future demand.

• The Journal of Korean Society for Radiation Therapy
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• v.35
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• pp.23-31
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• 2023

Purpose: The purpose of this study is to evaluate the usefulness of Non-Treat Functionality Volumetric Modulated Arc Therapy(NTF-VMAT) and Treat Functionality VMAT(TF-VMAT) treatment plans in reducing the low-dose area during radiation therapy for patients with multiple metastatic cancers. Materials and Methods: The study was conducted on an Arccheck phantom, treatment planning target locations were set in pairs at intervals of 2 cm, 4 cm, and 6 cm on the X, Y, and Z axes. Based on these location settings, the volume of the low-dose area in NTF-VMAT and TF-VMAT was measured and compared. Results: The results of the study showed that, within a prescription dose range of 10% ~ 70%, the difference in low-dose area volumes across each axis was as follows: On the X-axis, there was a maximum difference of -47.6% and a minimum difference of -2.2%. On the Y-axis, there was a maximum difference of -17.5% and a minimum difference of -7.3%. The Z-axis showed a maximum difference of -39.7%, with the smallest difference being -6.8%. Conclusion: In radiation therapy for patients with multiple metastatic cancers, the TF-VMAT treatment plan was able to reduce the low-dose area by 10-40% compared to NTF-VMAT. This suggests that utilizing Treat Functionality, which includes the Island block technique, improves dose distribution and minimizes side effects, making it beneficial for the treatment of patients with multiple metastatic cancers.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.78-99
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• 2020

The Buddha triad and 16 Arhat statues carved on the rock surface at Seongbulsa temple is the only domestic remaining example of all 16 Arhats, so its academic value is very high. However, it is severely damaged and so required a stability evaluation through study of digital documentation and precise diagnosis for the purpose of comprehensive conservation. This process established that the Buddha statues were of similar scale, while the Arhats showed a wide variety of sizes, and the two kith and kin in the volume were larger than the Arhats. It was estimated that the statues of food for Buddha are similar to the Arhat statues, and most of the statues are well-formed. The rock used to carve the Buddha statues is banded gneiss with distinct foliation, alternating between white bands of quartz and feldspar and black bands composed of biotite. The Buddha statues have been damaged by physical weathering, discoloration, and biological contamination. In damage evaluations, joint (3.6 crack index), peeling (5.2%), exfoliation (1.7%), and falling off (0.1%) were observed on the rock surface of the Buddha statues. In particular, due to severe biological weathering, stage 9 and 10 biological coverage of the rock surface accounted for 57.5% of the total area, and stages 5 to 8 also accounted for a high share at 22.3%. The discoloration factors were shown to be dark brown and white with Fe, Ca, and S, and a large amount of C detected in the blackened contaminants, and the damage weight high in all areas. Discontinuities in different directions were identified in the rock surface. Analysis of potential rock failure types indicated that there is a possibility of plane and toppling failure, but wedge failure is unlikely to occur. The mean ultrasonic velocity of the main rock surface was 2,463m/sec, the lower part of the left side with a large number of joints was relatively low, and the highly weathered (HW) type to the completely weathered (CW) type concentrated distribution, showing weak properties. For the Buddha statues, conservation treatment is required for about 14.9% of micro cracks and 58.9% of exfoliation cracks. In addition, in order to improve the conservation environment of the Buddha statues, maintenance of drainage and ground preparations for the rock surface gradient and plants are necessary, and protection facilities should be reviewed for long-term conservation and management purposes.

• Radiation Oncology Journal
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• v.6 no.1
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• pp.63-73
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• 1988

One hundred fifty-four patients with the carcinoma of the uterine cervix were studied retrospectively to assess the result and impact of treatment at Department of Radiation Oncology, Korea University, Hae-Wha Hospital from Feb 1981 through Dec. 1986. Prior to radiotherapy, the patients were evaluated and staged by recommendation of FIGO including physical examination, pelvic examination, cystoscopy, rectosigmoidoscopy, chest X-ray, IVP. Ba enema. Also, an additional pelvic CT scan was obtained for some of the patients. The patients were treated by radiotherapy alone or adjuvant postoperative irradiation; in case of radiation therapy only, whole pelvic irradiation was given with Co-60 teletherapy unit via AP and PA parallel opposing fields or 4-oblique fields, 180 cGy per day, 5 days per week and intracavitary insertion was performed. In satges Ia, Ib, and IIa with small primary lesion, external irradiation was initially given to pelvis up to $2,000\~3,000\;cGy/2frac{1}{2}\;-3frac{1}{2}$ weeks and then intracavitary insertion was performed using Fletcher-Mini-Declos Applicator with cesium-137 cources and followed by external irradiation of $1,000\~2,000\;cGy/1frac{1}{2}\;-2frac{1}{2}$weeks via AP and PA parallel opposing fields with midline shield to spare of bladder and rectum. However, if the primary lesion is large, external irradiation was given without midline shield. More than stages IIb, the patients were treated by external beam irradiation up to 5,400cGy/30f for 6 weeks via 4-oblique portals and at the dose of 5,040cGy/28f the field was cut 5cm from the top margin for spare of small bowel, and followed by intracavitary irradiation, If there was residual tumor an additional dose of $900\~l,200cGy/5\~7f$ was given to parametrium and/or residual tumor area. Total dose of radiation to A and B-point were as follows; A-point; In early stages, Ia, Ib, IIa; $8,000\~9,000$ B-point $5,000\~6,000 cGy$ A-point; In advanced stages IIb, IIIa, IIIb; $9,000\~10,000$ B-point $60,000\~7,000cGy$ The results were obtained and as fellows; 1 The patients distribution according to FIGO staging system were stage Ia 6, Ib 27, IIa 28, IIb 54, IIIa 12, IIIb 18, and stage IVa 9. 2. Value of CT scan were demonstration of cervix tumor mass, parametrial and pelvic side wall tumor spread, pelvic and inguinal lymph nodes metastases, and hydronephrosis. Three dimensional quantitative demonstration of tumor volume is also important in planning radiation therapy. Another advantage of CT scan was detection of recurrent tumor after radiation or surgery. 3. Local control rate of tumor according to the size was $91.3\%$ for less than 5cm in size and $44.6\%$ in tumor over 5cm (p<0.0068). 4. Thirty out of 50 recurrent sites has locoregional failures and 17 cases has distant metastases. And the para-aortic lymph nodes were the most common site for distant metastases. 5. The most common complication was temporal rectal bleeding which was controlled most by conservative management. However, 4 patients required for endoscopic cauterization. 6. The 5-year survival rates showed; stage la and Ib $95\%,\;stage\;IIa\;81\%\;stage\;lIb\;67\%,\;stage\;IIIa\;37.7\%,\;stage\;IIIb\;23\%$ and 3-year survival rate of stage IVa showed $11.6%$, retrospectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3734-3740
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• 2014

The aim of this study was provide basic information and establish the criteria in radiation therapy planning by measuring the absorbed neutron dose of normal tissues and lesions according to the number of portals. From September 2013 to January 2014, 20 patients who were diagnosed with prostate cancer and were previously treated with radiation therapy were replanned retrospectively to measure the absorbed neutron dose distribution according to the number of portals. The absorbed neutron dose was measured in each of the 5, 7 and 9 portals using a 15 MV energy, which meant a therapeutic dose of 220 cGy. The optical stimulation luminescence dosimeter was separated by 20cm and 60cm away from the center of the field of view. As a result, the average radiation dose in the abdomen appeared to have a positive relationship with the number of portals, which was statistically significant (p<.05). The average radiation dose was $4.34{\pm}1.08$. The average radiation dose in the thyroid was $2.71{\pm}.37$. Although it showed a positive relationship with the number of portals, it did not have statistical significance. The number of portals and the neutron dose depending on the position showed a significant positive relationship, particularly in the abdomen. As a result of linear regression analysis, as the number of the portal increased in steps, the average volume of the neutrons increased significantly (0.416 times). In conclusion, efficient selection of the number of portals is needed considering the difference in the absorbed neutron dose in the normal tissues depending on the number of the portals.