• Radiation Oncology Journal
• /
• v.16 no.3
• /
• pp.325-335
• /
• 1998

Purpose : Since the mid cranial fossa is composed of various thickness of bone, the tissue inhomogeneity caused by bone would produce dose attenuation in cobalt-60 gamma knife irradiation. The correction factor for bone attenuation of cobalt-60 which is used for gamma knife source is -3.5$\%$. More importantly, nearly all the radiosurgery treatment planning systems assume a treatment volume of unit density: any perturbation due to tissue inhomogeneity is neglected, This study was performed to confirm the bone attenuation in mid cranial fossa using gamma knife. Materials and Methods : Computed tomography was performed after Leksell stereotactic frame had been liked to the Alderson Rando Phantom (human phantom) skull area. Kodak X-omat V film was inserted into two sites of pituitary adenoma point and acoustic neurinoma point, and irradiated by gamma knife with 14mm and 18mm collimator. An automatic scanning densitometer with a 1mm aperture is used to measure the dose profile along the x and y axis. Results : Isodose curve constriction in mid cranial fossa is observed with various ranges. Pituitary tumor point is greater than acoustic neurinoma point (0.2-3.0 mm vs 0.1-1.3 mm) and generally 14 mm collimator is greater than 18mm collimator (0.4-3.0 mm vs. 0.2-2.2 mm) Even though the isodose constriction is found, constriction of 50$\%$ isodose curve which is used for treatment reference line does not exceed 1 mm. This range is too small to influence the treatment planning and treatment results. Conclusion : Radiosurgery planning system of gamma knife does not show significant error to be corrected without consideration of bone attenuation.

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.3
• /
• pp.255-264
• /
• 2009

To evaluate the effects of chemical pretreatments of lignocellulosic biomass on enzymatic hydrolysis process, Populus euramericana was pretreated for 1 hr with 1% sulfuric acid ($H_2SO_4$) at $150^{\circ}C$ and 1% sodium hydroxide (NaOH) at $160^{\circ}C$, respectively. Before the enzymatic hydrolysis, each pretreated sample was subjected to drying process and thus finally divided into four subgroups; dried or non-dried acid pretreated samples and dried or non-dried alkali pretreated samples and chemical and physical properties of them were analyzed. Biomass degradation by acid pretreatment was determined to 6% higher compared to alkali pretreatment. By the action of acid ca. 24.5% of biomass was dissolved into solution, while alkali degraded ca. 18.6% of biomass. However, reverse results were observed in delignification rates, in which alkali pretreatment released 2% more lignin fragment from biomass to the solution than acid pretreatment. Unexpectedly, samples after both pretreatments were determined to somewhat higher crystallinity than untreated samples. This result may be explained by selective disrupture of amorphous region in cellulose during pretreatments, thus the cellulose crystallinity seems to be accumulated in the pretreated samples. SEM images revealed that pretreated samples showed relative rough and partly cracked surfaces due to the decomposition of components, but the image of acid pretreated samples which were dried was similar to that of the control. In pore size distribution, dried acid pretreated samples were similar to the control, while that in alkali pretreated samples was gradually increased as pore diameter increased. The pore volume which increased by acid pretreatment rapidly decreased by drying process. Alkali pretreatment was much more effective on enzymatic digestibility than acid pretreatment. The sample after alkali pretreatment was enzymatically hydrolyzed up to 45.8%, while only 26.9% of acid pretreated sample was digested at the same condition. The high digestibility of the sample was also influenced to the yields of monomeric sugars during enzymatic hydrolysis. In addition, drying process of pretreated samples affected detrimentally not only to digestibility but also to the yields of monomeric sugars.

• The Korean Journal of Food And Nutrition
• /
• v.14 no.1
• /
• pp.34-39
• /
• 2001

The purpose of this study was to examine physical properties of the addition of green tea powder on bread flour and dough rheology of white pan bread. Three levels(0.1, 0.5 and 1.0% ) of each green tea powder with bread flour were tested for their effects in dough mixing using rapid disco analyzer, alveogram and farinogram. Addition of green tea powder tended to reduce initial pasting temperature and increase peak viscosity, break down and set back. L(extensibility) and G(swelling index) value in alveogram showed decrement with increasing green tea powder. These meant that the volume of white pan bread would show same tendency. The use of green tea powder increased consistency and water absorption of the bread flour but decreased development time, salability and degree of softening on farinogram. White pan bread with green tea powder had higher value of hardness and springness than without it. Sensory evaluation determined that the white pan bread with 0.5% green tea powder had the highest score.

• Journal of Korea Water Resources Association
• /
• v.42 no.11
• /
• pp.911-920
• /
• 2009

Virtual water is defined as the volume of water required to produce a commodity or service. The degree of food self-sufficiency is currently about 27 % in South Korea, so that Korea is one of the largest net virtual water import countries for agricultural product, thus it is necessary to estimate suitable virtual water for South Korea. The objective of this paper is to quantify the agricultural virtual water use (AWU) and virtual water content (VWC) using the method suggested by Chapagain and Hoekstra during the period 1991-2007. To calculate the virtual water content, 44 different crop production quantity and harvested area data were collected for 17 years and FAO Penman-Monteith equation was adapted for computing crop consumptive use of water. As the results, AWU has been estimated at 15.1 billion $m^3$ in average showing a tendency to decrease. Rice has the largest share in the AWU, consuming about 10.1 billion $m^3$/yr which is about 75 % of gross AWU, and the VWC is 1600.1 $m^3$/ton for paddy rice. The largest VWCs of crops are oilseed and tuber crop, and the smallest are leaf and root vegetables. The primary crop production VWC can be used for calculating the VWC of various secondary products using the contribution ratio, therefore the results of this study are expected to be used as basic data for national agricultural water footprint.

• Clinical and Experimental Pediatrics
• /
• v.45 no.5
• /
• pp.588-595
• /
• 2002

Purpose : The incidence of obesity has increased in Korea recently. Obesity leads to higher risks of hypertension, hyperlipidemia and insulin resistance. It also leads to risks of respiratory complications. This study was performed to see the effects of obesity on children's pulmonary functions and on developed bronchospasm after exercise loading according to their obesity degrees. Methods : 257 obese children and 150 non-obese children were enrolled. Obese children were divided into 3 groups by the obesity degrees. Pre- and post-exercise loading $FEV_1$(forced expiratory volume at one second), FVC(forced vital capacity) and PEFR(peak expiratory flow rate) were checked in all subjects. The percent predicted values of each parameter was compared according to obesity degrees and the differences between pre-exercise and post-exercise values. Results : The percent predicted value of $FEV_1$, FVC decreased only in the severe obesity group compared with those in the control group. However percent predicted PEFR declined according to obesity degrees. The percent predicted value of $FEV_1$, FVC and PEFR after exercise loading were much lower than those before exercise loading in all groups. Conclusion : As the degree of obesity was higher, the percent predicted value of pulmonary function was lower. And after exercise loading, as the degree of obesity was higher, the reduction of percent predicted value of pulmonary function was larger. Therefore the pulmonary function in obese children must be observed carefully. Further studies on the effects of pulmonary functions in obese children are necessary.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.45
• /
• pp.191-238
• /
• 2010

The purpose of this paper is to make research on the trend of the worldwide medical device market, the trend of the medical device market in the major foreign countries, the present status of the medical device industry in Korea and Gangwon area, the present status of export competitive power and the SWOT analysis of competitive power of the medical device industry in Gangwon area, and the strengthening methods of export competitive power of the medical device industry in Gangwon area. As the research method, the questionaire for the strengthening of export competitive power of the medical device industry in Gangwon area was carried out from August 13 to Otober 22, 2009. The worldwide medical device market in 2008 is estimated at USD 210.2 billion, with the United States being the largest market, followed closely by Japan and Western Europe. In 2006, the worldwide export amount of medical devices recorded USD 121.1 billion and the worldwide import amount of medical devices recorded USD 126.3 billion. As of the end of 2008, the number of Korea's medical device manufacturers expanded to 1,726. The production amount of Korea's medical device industry in 2008 recorded 2,525 billion won, and the domestic market volume of medical devices in 2008 recorded 3,618 billion won. Korea's export amount of medical devices in 2008 recorded USD 1,132 million and recorded a 9.67% growth compared to the previous year, and the import amount of medical devices recorded USD 2,123 million and recorded a 1.43% reduction compared to the previous year. As of the end of 2008, the number of Gangwon area's medical device manufacturers expanded to 81. The production amount of Gangwon area's medical industry in 2008 recorded 380 billion won, and Gangwon area's export amount of medical devices recorded USD 269 million and recorded a 0.25% reduction compared to the previous year, and the import amount of medical devices recorded USD 3 million and recorded a 39.63% reduction compared to the previous year. According to the result analysis of the questionaire for the strengthening of export competitive power of medical device industry in Gangwon area(August 13~October 22, 2009), the competing country of the export medical device is the United States being the highest ranking. Comparing to the collective competitive power level 100 of the competing country, the collective competitive level of the export medical device is 60 below and 70-80 below being the highest ranking. Comparing to the quality level 100 of the United States, EU and Japan, the quality level of the export medical device is 80-90 below being the highest ranking. Comparing to the design level 100 of the United States, EU and Japan, the design level of the export medical device is 90-100 below being the highest ranking. Comparing to the technology level 100 of the United States, EU and Japan, the technology level of the export medical device is 80-90 below being the highest ranking. According to the SWOT analysis of competitive power of medical device industry in Gangwon area, the strength is the abundant expert manpower of the medical device in Wonju area. The weakness is the fragility of the brand recognition of the medical device industry. The opportunity is the demand increase of the new medical device owing to the advanced age of population. The threat is the difficulty of entry into overseas market owing to the request of the new specification certification of the medical device. In order to strengthen the export competitive power of the medical device industry in Gangwon area, the following measures should be taken by the government, local self-government body, related organization and medical device industry : the development of new technology and design, the enhancement of brand recognition. the acquisition of the foreign specification certification, the building of overseas distribution channel and after sales service channel, the positive participation in overseas medical device exhibition and opening of medical device exhibition, the training of expert manpower, the strengthening of overseas marketing, and the application of FTA and the establishment of counter measures against FTA. In conclusion, the medical device industry in Gangwon area has the difficulty in the entry into the overseas market owing to the shortage of overseas marketing capability. Therefore, the government and local self-government body should make the intensive and systematical support for overseas marketing of the medical device industry. For the support of overseas marketing, the government and local self-government body should provide positively the support of expenses for the acquisition of foreign specification certification, the support of participation in the overseas medical device exhibition, the despatch of market development mission, the increase of the support amount for R&D investment fund, and the training of expert manpower of medical devices.

• Journal of Conservation Science
• /
• v.30 no.3
• /
• pp.263-275
• /
• 2014

It's shown how to proceed the study on Manufacturing techniques & Conservation to the Iron Pot from Cheonmachong Ancient Tomb(the 155th Tomb in Hwangnam-dong). In order to investigate manufacturing techniques of the Iron Pot, some parts of the relic were gathered. After mounting, polishing and etching on the relic, analyzing the metal microstructure was conducted. Also it's conducted a SEM-EDS analysis on the nonmetallic inclusion. White iron structure was observed in the metallurgical structure inspection, SEM-EDS analysis. It seems to be dried slowly at room temperature after casting, doesn't look as particular heat treatment to improve brittleness. It is estimated that it's as the handle seam side were verified about 3cm inch wide, 1.5 thick in center of body, so 2 separate half-completed products was cast with width-type mould. The manufacturing techniques Using white cast iron structure, width-type mould are observable to the Iron Pot excavated from Sikrichong Ancient Tomb & Hwangnamdaechong grand Ancient Tomb around those were constructed the same time. It's able to recognize that it's almost identical manufacturing techniques at that time. Conservation is generically following those are survey of pretreatment, foreign material removal, stabilization, restoration and color matching in the order. cleaning & drying were added to the process as occasion demands. The strengthening treatment were difficult with artifact's volume, low concentration Paraloid NAD-10 solution was spread two or three times with a brush, surface hardening also came up with 15wt% Paraloid NAD-10 solution after the conservation was complete. There were connection & restoration for the restoration to the damage after modeling forms that it's similar to damaged parts by using the Fiber Reinforced Plastic resins(POLYCOAT FH-245, mold laminated type). Throughout this research, capitalizing on accumulations of measurements about the production technique of Iron Pot in the time of the fifth and 6th centuries is no less important than the Iron artifact's conservation for a better study in the future.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.1 no.1
• /
• pp.41-51
• /
• 1999

This study was conducted to investigate the effects of local climatic conditions on the annual increment of Korean white pine planted in Gapyung and Yaungdong. For this, stand variables such as mean DBH, mean height, basal area per hectare, and volume per hectare by stand age were measured and summarized for each locality. Based on these statistics, annual increments for 8 years from stand age 10 to 18 were calculated for each of stand variables. A topoclimatological technique which makes use of empirical relationships between the topography and the weather in study sites was applied to produce normal estimates of monthly mean, maximum, minimum temperatures, relative humidity, precipitation, and hours of sunshine. Then, the yearly climatic variables from 1990 to 1997 for each study site were derived from the spatial interpolation procedures based on inverse- distance weighting of the observed deviation from the climatic normals at the nearest 11 standard weather stations. From these estimates, 17 weather variables such as warmth index, coldness index, index of aridity etc., which affect the tree growth, were computed on yearly base for each locality. The deviations of measured annual increments from the expected annual increments for 8 years based on yield table of Korean white pine were then correlated with and regressed on the yearly weather variables to examine effects of local climatic conditions on the growth. Gapyung area provides better conditions for the growth of Korean white pine in the early stage than Youngdong area. This indicates that the conditions such as low temperature, high relative humidity, and large amount of precipitation provide favor environment for the early growth of Korean white pine. A ccording to the correlation and regression an analysis using local climatic conditions and annual increments, the growth pattern of Gapyung area corresponds to this tendency. However, it was found that the relationship between annual increments and local climatic conditions in Youngdong area shows different tendency from Gapyung. These results mean that the yearly growth pattern could not sufficiently be explained by climatic conditions with high variance in yearly weather variables. In addition, the poor growth in Youngdong area might not only be affected by climatic conditions, but also by other environmental factors such as site quality.

• The Journal of Korean Society for Radiation Therapy
• /
• v.16 no.1
• /
• pp.1-9
• /
• 2004

Purpose : The aim of this study is to investigate the properties of small field size and to measure the penumbra and central axis depth dose varying to the jaw setting and off axis distance for indicate this data to small field sizes radiation therapy. Material and methods : The percentage depth dose, beam profile and central axis output dose was measured by farmer type ion chamber and pinpoint chamber using Primart linac with 6MV energy. Beam quality and penumbra variations according to the central axis shift, from center to every 2cm outside increment, and field size, from $1{\times}1cm$ to $10{\times}10cm$ was investigated and compared with that of the standard geometrical condition's results Results : The differences of measured values between two ion chamber was about $37\%$ at 10cm depth with $1{\times}1cm$ field sizes but as field size increased this differences was diminished gradually. Measured data from various off axis distance with the different asymmetric collimations are not changed significantly but as size decreased the dose variation was increased and at $1{\times}1cm$ field size dose difference among off axis distance was as much as $13\%$, and as shallower the measured depth the central axis dose variations among the OAD was increased, penumbra was not changed noticeably depending on off axis distance but the percentage of penumbra from its initial field sizes was strongly dependant on field sizes and penumbra occupation rates of its own field sizes ranging from $6\%$ at $10{\times}10cm$ to $50\%$ at $1{\times}1cm$ field size. Conclusion : For imrt treatment, there are several numbers of different gentry angles with beams of nonuniform fluences are required and several complex factors involved. Among them the characteristics of beam output varying to the geometrical setting and design of collimators are of important to attaining a good treatment results. As mentioned in results the differences of measured values are changed significantly depends on ion chamber volume, depths and field size. For providing quality radiation treatment, especially at small field size, those factor's should have considering deliberately.

• The Journal of Korean Society for Radiation Therapy
• /
• v.26 no.1
• /
• pp.91-98
• /
• 2014

Purpose : To compare the dosimetry for the left breast cancer treatment between three dimensional conformal radiation radiotherapy (3D-CRT) and Hybrid planning and to estimate usefulness of Hybrid planning Materials and Methods : Five patients with left breast cancer were included in the study. They were planned using several different radiotherapy techniques including: 1)open rectangular field, 2)tangential wedge-based field 3)field in field, 4)hybrid planning(energy, wedge combine). For each patient planning was using Light Speed RT-16 CT and PINNACLE planning system-ver.9.2. Hybrid plan was made using same system and using the same targets and optimization goals. We comparing the Homogeneity Index(HI), normal organs at the does-volume histogram(DVH) Results : In all plans, the Homogeneity Index(HI) of Hybrid planning was significantly better than other. Dose comparison of HI= 2D-RT:38.32, TW:38.32, FIF:29.22, HYBRID:30.57. 2D-RT, TW, FIF Hybrid$V_{75_-lung}$=112.33, 125.14, 121.3, 123.78. $V_{50_-lung}$=155.43, 159.62, 157.96, 159.06. $V_{25_-lung}$=199.86, 200.22, 198.65, 200.31. $V_{50_-heart}$=26.07, 27.1, 26.85, 27.17 $V_{30_-heart}$=33.71, 34.37, 34.15, 34.65 Conclusion : In summary, 3D-CRT, Hybrid planning techniques were found to have acceptableCTV coverage in our study. However the Hybrid planning increased radiation dose exposure to normal tissue. If you apply for treatment of inhomogeneity areas like lung, For best results will be achieved.