• Radiation Oncology Journal
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• v.15 no.1
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• pp.71-78
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• 1997

Purpose : To collect beam data for dynamic wedge fields using conventional measurement tools without the multi-detector system, such as the linear diode detectors or ionization chambers. Materials and Methods : The accelerator CL 2100 C/D has two photon energies of 6MV and 15MV with dynamic wedge an91es of 15o, 30o, 45o and 60o. Wedge transmission factors, percentage depth doses(PDD's) and dose Profiles were measured. The measurements for wedge transmission factors are performed for field sizes ranging from $4\times4cm^2\;to\;20\times20cm^2$ in 1-2cm steps. Various rectangular field sizes are also measured for each photon energy of 6MV and 15MV, with the combination of each dynamic wedge angle of 15o 30o. 45o and 60o. These factors are compared to the calculated wedge factors using STT(Segmented Treatment Table) value. PDD's are measured with the film and the chamber in water Phantom for fixed square field. Converting parameters for film data to chamber data could be obtained from this procedure. The PDD's for dynamic wedged fields could be obtained from film dosimetry by using the converting parameters without using ionization chamber. Dose profiles are obtained from interpolation and STT weighted superposition of data through selected asymmetric static field measurement using ionization chamber. Results : The measured values of wedge transmission factors show good agreement to the calculated values The wedge factors of rectangular fields for constant V-field were equal to those of square fields The differences between open fields' PDDs and those from dynamic fields are insignificant. Dose profiles from superposition method showed acceptable range of accuracy(maximum 2% error) when we compare to those from film dosimetry. Conclusion : The results from this superposition method showed that commissionning of dynamic wedge could be done with conventional dosimetric tools such as Point detector system and film dosimetry winthin maximum 2% error range of accuracy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.2 no.3
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• pp.33-41
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• 1982

Development is given for an analytical approach that can investigate parameters characterizing road network geometry. A grid transportation network having a hierarchy structure is considered on a homogeneous and isotropic urban plane in which trip origins and destinations are uniformly dispersed and the trip length distribution is independent of the location of the origin. The object is to find the optimal spacings between urban arterials so as to minimize the sum of travel and construction costs, subject to the hypothesis that a trip assignment follows the Wardrop's first principle. The proposed approach is not the genera method for determining an efficient network layout, but can be used as basic concept for generating and evaluating urban road network alternatives. Given an O-D table and cost estimates the approach is able to outline at least in a qualitative sense the optimal spacings of urban arterial roads.

• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.179-188
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• 2005

Much research for spatial join has been extensively studied over the last decade. In this paper, we focus on the filtering step of candidate objects for spatial join operations on the input tables that none of the inputs is indexed. In this case, many algorithms has presented and showed excellent performance over most spatial data. However, if data sets of input table for the spatial join ale skewed, the join performance is dramatically degraded. Also, little research on solving the problem in the presence of skewed data has been attempted. Therefore, we propose a spatial hash strip join (SHSJ) algorithm that combines properties of the existing spatial hash join (SHJ) algorithm based on spatial partition for input data set's distribution and SSSJ algorithm. Finally, in order to show SHSJ the outperform in uniform/skew cases, we experiment SHSJ using the Tiger/line data sets and compare it with the SHJ algorithm.

• Journal of Technology Innovation
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• v.8 no.1
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• pp.73-94
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• 2000

The main objective of this research is to examine the spillover effects of technological knowledge from IT industry to other industrial sectors and, based on empirical findings, to draw policy implications and suggest policy directions. To this end, we divide IT industry into IT equipment and IT service, assuming that these two sub-sectors are considerably different each other in terms of technology knowledge flow. Other industries are classified into 17 different sectors based on the KSIC of 1990. As the proxy measure of technological knowledge, the notion of R&D stock is employed. The Input/output(I/O) Table is used to define the inter-industrial flow pattern and to draw the knowledge flow matrix. As the research methodology, cost function model is employed to gauge the spillover effects of technological knowledge of IT industry. Based on the results of analysis, it is found that the economic impact of technology diffusion also exhibits a different pattern between IT equipment and IT service. The diffusion of IT equipment tends to show labor-substitution effect whereas IT service displays labor-creation effect. This fact should be considered in devising industry, education, and labor policy. The expectations from this research are as follows. First, the sectoral pattern, difference between IT equipment and service in particular, identified from this research may shed light on the sector-specific policy direction. It is emphasized that a sector-specific approach, rather than an aggregate approach, is relevant for formulating IT policy. Second, it is expected that the importance of technology diffusion programs and policy measures are recognized among policy makers in IT industry.

• Journal of Information Technology Services
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• v.17 no.1
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• pp.47-58
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• 2018

In this study, we define Fintech services as review previous literatures and identify the traditional Fintech service market for analysing the economic effects of the Fintech Industry by using the 2014 Input-Output Table. We can identify the current market of Fintech industry which consists of VAN, PG, financial SW, mobile banking and Fintech R&D and we conduct Input-Output analysis by using non-competitive import model. The Input-Output analysis results show that production inducement effect and front/rear chain effect of the Fintech Industry are below average of other industries. This is because the Fintech technology and industry were emerging in Korea at that time (2014), and thus the ripple effects are not significant. Especially, due to the existing white risk financial regulation, new business opportunities have not been open to adapt new ICT-financial technologies. Therefore, when the business ecosystem is build through deregulation and platforms of the financial sector, it is expected that the Fintech Industry will have a high ripple effect. In this study, we identify the current market of Fintech industry from ICT indusries and conduct Input-Output analysis. The economic effects of the Fintech industry are not remarkable, but it is significant to identify the emerging market and present the basic analysis of issued research field.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.2
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• pp.127-133
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• 2015

The error motion of a machine tool spindle directly affects the surface errors of machined parts. Those are usually due to the imperfectness of bearings, stiffness of spindle, assembly errors, external force or unbalance of rotors. The error motions of the spindle have been needed to be decreased to desired goal of spindle's performance. The level of error motion is needed to be estimated during the design and assembly process of the spindle. In this paper, the estimation method for the five degree of freedom (5 D.O.F) error motions for rotary units such as a spindle and rotary table are suggested. To estimate the error motions of the rotary unit, waviness of bearings and external force model were used as input data. The estimation model considers geometric relationship and force equilibrium of the five degree of the freedom motions.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.284-287
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• 1987

In this paper, the design and implementation of a multiprocessor based Die Bonder Machine for the semiconductor will be described. This the partial research result, that is, the 1st year portion of the project to be performed for a period of two years from June, 1986 to May, 1988. The mechanical system consists of the following three subsystems : (i) transfer head unit, (ii) die feeding XY-table unit, and (iii) plunge up unit. The overall control system is designed to be essentially a master-slave type in which each slave is functionally fixed in view of software and also the time shared common bus structure with hardwired bus arbitration scheme is utilized, the control system consists of the following three subsystems each of which employs a 16 bits microprocessor MC 68000 : (i) die bonder processor controller, (ii) visual recognition/inspection and display system, (iii) the servo control system. It is reported that the proposed control system were applied to Working Sample and tested in real system, and the results are successful as a working sample phase.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.2
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• pp.63-69
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• 2011

Table strapis patient fixture for securing the patient movements and falls. if it designed to measure the abdominal circumference and used as an indicator of dose selection at CT scan. it will prevent the overexposure of dose without degradation of image quality and efficiently manage dose of each type of body to technician to deal with CT. First, in order to compare the dose used in CT image and qualitative characteristics. reference image is obtained by examining the abdominal phantom in same conditions with the hospital 120 kVp, 200 mAs, D-Dom (Dynamic Dose Of Modulation). SNR, PSNR, RMSE, MAE, CTDIvol of CT images are compared with reference image. for comparing with reference image, the image that Umbilicus level image of Abdomen CT is stored in the PACS were used. For comparison, the top 12 o'clock portion of the air drawn from the same ROI was measured. CTDIvol, mAs, etc. In order to analyze the characteristics of the image, by measuring the length of the umbilicus circumference, pattern of the dose was analyzed. by using the analyzed perimeter and dose information, To be identified visually, fixed band that scale marked were produced. Use them, If the length of circumference of less than 60 cm 100 mAs, Case of 61~80 cm 120 mAs, Case of 80~100 cm 150 mAs, more than 100 cm 200 mAs, dose selection based on the perimeter, the image was applied. by compare analyzed with the Reference Image, image quality was assessed. by compare with existing tests that equally 200 mAs applied, How much was confirmed that the dose reduction. 1. Depending on the Abdominal circumference, the average PSNR(dB) of the image that differently dose applied was 45.794. 2. Comparing with existing test. the dose of scan that adjusted the mAs depending on the circumference was decreased about 40%. SNR and PSNR of the image that obtained by adjusting the standard mAs based on dose modulation were not much different. Therefore, By choosing a low mAs. dose reduction can be obtained. and the dose selection method that measured Abdominal circumference using a fixed band can protect the overexposure and uniformly apply dose of each type of body to technician to deal with CT.

• Economic and Environmental Geology
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• v.26 no.1
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• pp.11-20
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• 1993

In the present study, three representative hydrothermal clay deposits, named the Seongsan, Ogmaesan and Haenam deposits, were selected for oxygen and hydrogen isotope studies. Oxygen and hydrogen isotopic compositions of quartz, sericite, alunite and kaolin minerals from Seongsan, Ogmaesan, Haenam deposits and surrounded rocks of clay deposits have been measured. The ${\delta}^{18}O$ values of quartz, kaolin, sericite and alunite in the Seongsan mine are +8.4 to +11.1‰, +3.6 to 5.4‰, +4.8 to +5.8‰ and + 3.0 to +6.6‰, respectively. In the Ogmaesan mine, the ${\delta}^{18}O$ values of quartz, kaolin, sericite and alunite are +8.0 to +13.6‰, +2.8 to +6.7‰, +4.8 to +8.4‰ and +0.9 to +2.4‰, respectively. The ${\delta}^{18}O$ values of the Haenam mine range from +7.9 to +10.1‰ for quartz and from +4.5 to +6.5‰ for sericite. The ${\delta}^{18}O$ values of the whole-rocks range from + 3.0 to + 7.8‰ for the granitic rocks. The ${\delta}^{18}O$ values of the whole-rocks range from + 3.2 to + 10.7‰ for the volcanic rocks. The 8D values of kaolin, sericite and alunite in the Seongsan mine are -78 to -86‰, -71 to -90‰ and -43 to -77‰, respectively. In the Ogmaesan mine, the ${\delta}D$ values of kaolin, sericite and alunite are -73 to -80‰, -74 to -88‰ and -57 to -98‰, respectively. The ${\delta}D$ values of the Haenam mine range from -76 to -85‰ for sericite. The ${\delta}D$ values of the whole-rocks range from -77 to -105‰ for the granitic rocks. The ${\delta}D$ values of the wholerocks range from -76 to -100‰ for the volcanic rocks. The main result obtained oxygen and hydrogen isotope data can lead to the following interpretations on the origin of hydrothermal fluids in the clay deposits: Through the oxygen isotopic study, the formation temperature of the clay deposits was estimated from the coexisting minerals such as quartz-kaolin minerals and -sericite. Formation temperature of the acidic alteration zone is 165 to $280^{\circ}C$ in the Seongsan deposits, 175 to $250^{\circ}C$ in the Ogmaesan deposits and 250 to $350^{\circ}C$ in the Haenam deposits. Three clay deposits has been formed by magmatic water mixed with meteoric water. Furthermore, from this isotopic data, it is clarified that kaolin minerals and alunite are hypogene in origin, and has been formed by oxidation of hydrogen sulfide in the steam-heated environment, and that alunite has been produced in the spectacular solfataric alteration observed at the surface of some present-day hydrothermal systems. Oxidation of the $H_2S$ is thought to be generated when the vapor phase generated by boiling of the deep-seated water under the water table.

• Journal of Nutrition and Health
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• v.22 no.2
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• pp.84-90
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• 1989

Allergic disorders may be defined as the abnormal reactions to proteins. Cow milk is the first foreign protein which the human being would contact postnatally. Serveral studies suggested that this contact had certain effects on the development o allergic disorders with great controlversies. Seven hundred seventy eight students from middle class in Seoul, aged 6 to 17 wears, were surveyed to delineate the relationshpis between the cow's milk contacts in infancy and the subsequent development of allergic disorders in Koran population. Questionaire were included the nursing patterns in infancy, the past medical history of asthma or wheezy bronchitis and the presence of infantile eczema. Skin tests to three common resporatory allergens in Korea(house dust, house dust mite; D. farinae, D. ptoeronssinus) were performed. The positivity was determined by the wheal size larger than that to histamine. 70.2% of whole mateials was fed by breast milk, 13.1% by cow's milk and 16.7% by mixed nutsing. From the obsevation of nursing patterns by (table 2), we find that the number of breast milk group has been decreasing in 1970's. 10.1% of breast milk group(BMG) had wheezy bronchitis, 8.8% of cow's milk group(CMG) and 11.5% of mixed nursing group(MNG). Infantile eczema history was positive in 27.8% of BMG, in 26.5% of CMG and in 29% of MNG. Skin test positivity was 23.8% in BMG, 25.5% in CMG and 26.2% in MNG. There prevalences of allergic disorders in each nursing group did not reveal any statistically significant differences. In conclusion, nursing patterns in infancy do not seem to have certain effects on the development of allergic disorders such as infantile eczema. wheezv bronchitis or skin test positivity.