• The Journal of Engineering Geology
• /
• v.30 no.4
• /
• pp.557-575
• /
• 2020

Plasma blasting which is generated by high voltage arc discharge of electricity is applied to soil mass to improve permeability of soil and cleaning efficiency of oil contamination. A new high voltage generator was manufactured and three types of soil including silty sand, silty sand mixed with lime and silty sand mixed with cement were prepared. Small and large soil columns were produced using these types of soil and plasma blasting was performed within soil columns to investigate the variation of soil volume penetrated by fluid and permeability. Soil volume penetrated by fluid increased by 11~71% when plasma blasting was applied in soil. Although plasma blasting with low electricity voltage induced horizontal fracture and fluid penetrated along this weak plane, plasma blasting with high voltage induced spherical penetration of fluid. Plasma blasting increased the permeability of soil. Permeabilty of soils mixed with lime and cement increased by 450~1,052% with plasma blasting. Permeability of soil increased as discharge voltage increased when plasma blasing was applied once. However, several blastings with the same discharge voltage increase or decrease permeability of soil. Oil contaminated soil was prepared by adding diesel into soil artificially and plasma blasting was performed in these oil contaminated soil. Cleaning efficiency increased by average of 393% for soil located nearby the blasting and by average of 239% for soil located far from the blasting. Cleaning efficiency did not show any correlation with discharge voltage. All these results indicated that plasma blasting might be used for in-situ cleaning of oil contaminated soil because plasma blasting increased permeability of soil and cleaning efficiency.

• Journal of the Korean Orthopaedic Association
• /
• v.54 no.4
• /
• pp.343-352
• /
• 2019

Purpose: The purpose of this study was to document the sonographic morphology of the subscapularis footprint, particularly the 1st facet, of the non-pathologic subscapularis tendon and footprint, and analyze the correlation between the size of the 1st facet and the demographic variables. Materials and Methods: Between March 2015 and December 2017, retrospectively data analysis was performed for the ultrasound (US) scans of 115 consecutive shoulder (mean age 53.4 years, range 23-74 years) with non-pathologic subscapularis tendon and footprint. The sonographic findings of the 1st facet of the subscapularis footprint was a very unique, flat, broad, and plane angle in the upward direction, which were distinguished from the other facets. On US, the transverse (medio-lateral) and longitudinal (superior-inferior) length of the 1st facet on axis of the humerus shaft were recorded. The demographic variables, including age, site, body height, weight, body mass index (BMI), and arm length, were reviewed. Results: On US, the mean transverse length of the 1st facet was 12.75 mm (range 10.54-14.50 mm, standard deviation [SD] 0.712) and the mean longitudinal length was 12.22 mm (range 9.20-13.30 mm, SD 0.888). The transverse and longitudinal length of the size of the 1st facet were significantly greater in males than in females (p<0.001, p=0.001). Of the demographic data (body height, weight, BMI, arm length) that showed a significant positive linear correlation, the correlation with body height (transverse r=0.749, p<0.001; longitudinal r=0.642, p<0.001) showed the strongest relationship, and the correlation with the BMI was weakly related. The relationships between the size of the 1st facet to site/age were not statistically significant or appeared to have no linear correlation. Conclusion: The structural and morphologic features of the 1st facet of the subscapularis footprint on the US were identified. This will provide anatomic knowledge of an US examination for subscapularis tendon pathology.

• Journal of Technologic Dentistry
• /
• v.32 no.4
• /
• pp.417-433
• /
• 2010

Purpose: This study evaluated the manpower planning of dental technicians. Methods: Methods : Survey was conducted regarding subject's general characteristics, characteristics of dental technician's occupational view and working conditions, and reason to enter into branches of the public health enter. The survey sample consisted of 323 dental technicians (221 male/ 102 female). Survey was conducted for one month from August 1 to September 1 in 2010. Following results were obtained. Results: 1. Regarding general characteristics of the subjects, there was a slight male predilection with 68.4%. Subjects in their 40s occupied the highest proportion of 32.2%. Majority of subjects worked in the big cities (71.5%). Favored working places were dental laboratory (57.6%) and dental hospital or dental clinic (19.5%). Although no position is available in the public sector such as public health center or health care civil servant, 9.3% preferred working in the public health center. Public sector is more favored than 2-year technical colleges or dental supply and equipment companies. In respect to education, 57% of the subjects graduated college. 67.8% were married. Subjects who specialize in the porcelain or all-ceramic were 57.9%. With regard to current position, head of the dental laboratory was most common. 2. Following occupation characteristics were found. Economic reason took the highest proportion when deciding their occupation (39.9%) followed by gaining social experience (36.5%). Majority of the subjects (76.5%) wanted to work as dental technicians until their retirement. 71.5% pursuit to become a manager of the dental laboratory. 76.1% agreed on opening a dental technician position in the public health center. Regarding an authority to lead developing the dental technician position in the public sector, majority of the subject chose ministry of health and welfare (35.6%) and Korean dental technologist association (34.7%). Employment (average, 30%) and turnover rate (average, 36.5%) of dental technology college graduates ranged from 40% to 60%. Most important factors for the employment were practical experience (41.2%) and competency (34.4%). With regard to job satisfaction, so-so as 46.7% and satisfactory was 42.7% 3. In respect to the reason for opening a position in the public health center, 'It is needed to continue denture rogram for elderly patients' obtained the highest score (4.14 point). 'Institutional devices are required to open a position for dental technicians as a public healthcare provider' received high score (4.11 point). 4. Concerning the working conditions, 'professional knowledge is required' received the highest score (4.23) followed by 'too short maternity and parental leave' (4.21). 5. Relationship between general characteristics of the subjects and favor of working in the public health center was investigated. Significant differences were found according to the current and favored working area, favored occupation, education level, marital status, and specialty. Working in the public health center was favored by following subjects: working in mid- or small-sized cities (4.16 point, p<0.05); PhD degree-holder (4.59 point, p<0.01). 6. Among general characteristics of the subjects, significant difference of working conditions was found in the following factors: gender; working areas; favored working areas; favored working positions, and education level. Majority of subjects favored working in big cities and currently work in big cities although satisfaction was comparatively low (3.75 score). 7. Future plan to work in public health center was evaluated according to occupational characteristics. Subject's intention to work in the public healthcare center was significantly affected by opening of dental technician position, leading authority, average turnover rate, and factors affecting employment. Working in the public health care center was favored by the following subjects: Dental technicians who actively supported opening of the dental technician position (4.34 point, p<0.001); subjects who thought the Korean dental technologist association is responsible for the opening of positions in the public sector (4.26 point, p<0.001); and subjects who thought that attitude and character are important for the employment (p<0.001). 8. Concerning difference of working conditions according to the occupational characteristics, significant difference was demonstrated by factors such as a reason to choose to be a dental technician, work plan, pursuing position, responsible authority, average employment rate, and job satisfaction. High standard of working conditions was required in subjects who selected to be a dental technician for the leisure time after work (s.05 point, p<0.01), who planted to work until their marriage (4.25 point, p<0.001), and who pursuit to be a manager (3.98, p<0.05). 9. In respect to influence of general characteristics on the advancement to public health centers, the coefficient of determination (R2) was 0.068 and age affected the working condition with significant difference according to the pvalue. 10. Regarding influence of general characteristics on the advancement to public health centers, the coefficient of determination (R2) was 0.335 and work plan, opening of dental technician position in the public sector, and responsible authority had significant influence over the subject's intention to work in the public health center according to the p-value. 11. With regard to the influence of general characteristics on the advancement to public health centers, the coefficient of determination (R2) was 0.091 and reason to choose to be a dental technician, work plan, and responsible authority significantly affected subject's working conditions. Conclusion: Korean society is becoming a super-aged society according to several statistics. As aged population is rapidly increasing, national health insurance plans to cover denture for senior citizen over 75 years old from 2012. Therefore, dental technicians are urgently needed in the public health centers all over the nation. Many subjects in this study planed to work until their retirement and recognized dental technician's expertise. Ministry of health and welfare and Korean dental technologist association should co-operate each other to prepare foundation and institutional devices for dental technicians to advance into the public health center. This will improve oral health of the population. This study showed urgency of medical facilities and services which meets increasing number of aged population and welfare of the population.

• Journal of National Security and Military Science
• /
• s.13
• /
• pp.687-738
• /
• 2016

To prepare for the complicated international relationship regarding Korean Peninsula after reunification, this thesis started off with the awareness that Unified Korea should build its international posture and national security at an early stage by determining its appropriate military strength for independent defense and military strategies that Unified Korea should aim. The main theme of this thesis is 'The research on appropriate military strength of the Unified Korean military'. To derive appropriate military strength of Unified Korea, this research focuses on conflict scenario and relative balance strategy based on potential threats posed by neighboring countries, and this is the part that differentiates this research from other researches. First of all, the main objective of the research is to decide appropriate military strength for Unified Korea to secure defense sufficiency. For this, this research will decide efficient military strategy that Unified Korea should aim. Than by presuming the most possible military conflict scenario, this research will judge the most appropriate military strength for Unified Korea to overcome the dispute. Second, after deciding appropriate military strength, this research will suggest how to operate presumed military strength in each armed force. The result of this thesis is as in the following. First, Unified Korea should aim 'relative balance strategy'. 'Relative balance strategy' is a military strategy which Unified Korea can independently secure defense sufficiency by maintaining relative balance when conflicts occur between neighboring countries. This strategy deters conflicts in advance by relative balance of power in certain time and place. Even if conflict occurs inevitably, this strategy secures initiative. Second, when analyzing neighboring countries interest and strategic environment after unification, the possibility of all-out war will be low in the Korean Peninsula because no other nation wants the Korean Peninsula to be subordinated to one single country. Therefore appropriate military strength of the Unified Korean military would be enough when Unified Korea can achieve relative balance in regional war or limited war. Third, Northeast Asia is a region where economic power and military strength is concentrated. Despite increasing mutual cooperation in the region, conflicts and competition to expand each countries influence is inherent. Japan is constantly enhancing their military strength as they aim for normal statehood. China is modernizing their military strength as they aspire to become global central nation. Russia is also enhancing their military strength in order to hold on to their past glory of Soviet Union as a world power. As a result, both in quality and quantity, the gap between military strength of Unified Korea and each neighboring countries is enlarged at an alarming rate. Especially in the field of air-sea power, arms race is occurring between each nation. Therefore Unified Korea should be equipped with appropriate military strength in order to achieve relative balance with each threats posed by neighboring countries. Fourth, the most possible conflicts between Unified Korea and neighboring countries could be summarized into four, which are Dokdo territorial dispute with Japan, Leodo jurisdictional dispute with China, territorial dispute concerning northern part of the Korea Peninsula with China and disputes regarding marine resources and sea routes with Russia. Based on those conflict scenarios, appropriate military strength for Unified Korea is as in the following. When conflict occurs with Japan regarding Dokdo, Japan is expected to put JMSDF Escort Flotilla 3, one out of four of its Japan Maritime Self-Defense Force Escort Fleet, which is based in Maizuru and JMSDF Maizuru District. To counterbalance this military strength, Unified Korea needs one task fleet, comprised with three task flotilla. In case of jurisdictional conflict with China concerning Leodo, China is expected to dispatch its North Sea fleet, one out of three of its naval fleet, which is in charge of the Yellow Sea. To response to this military action, Unified Korea needs one task fleet, comprised with three task flotilla. In case of territorial dispute concerning northern part of the Korean Peninsula with China, it is estimated that out of seven Military Region troops, China will dispatch two Military Region troops, including three Army Groups from Shenyang Military Region, where it faces boarder with the Korean Peninsula. To handle with this military strength, Unified Korea needs six corps size ground force strength, including three corps of ground forces, two operational reserve corps(maneuver corps), and one strategic reserve corps(maneuver corps). When conflict occurs with Russia regarding marine resources and sea routes, Russia is expected to send a warfare group of a size that includes two destroyers, which is part of the Pacific Fleet. In order to balance this strength, Unified Korea naval power requires one warfare group including two destroyers. Fifth, management direction for the Unified Korean military is as in the following. Regarding the ground force management, it would be most efficient to deploy troops in the border area with china for regional and counter-amphibious defense. For the defense except the border line with china, the most efficient form of force management would be maintaining strategic reserve corps. The naval force should achieve relative balance with neighboring countries when there is maritime dispute and build 'task fleet' which can independently handle long-range maritime mission. Of the three 'task fleet', one task fleet should be deployed at Jeju base to prepare for Dokdo territorial dispute and Leodo jurisdictional dispute. Also in case of regional conflict with china, one task fleet should be positioned at Yellow Sea and for regional conflict with Japan and Russia, one task fleet should be deployed at East Sea. Realistically, Unified Korea cannot possess an air force equal to neither Japan nor China in quantity. Therefore, although Unified Korea's air force might be inferior in quantity, they should possess the systematic level which Japan or China has. For this Unified Korea should build air base in island areas like Jeju Island or Ullenong Island to increase combat radius. Also to block off infiltration of enemy attack plane, air force needs to build and manage air bases near coastal areas. For landing operation forces, Marine Corps should be managed in the size of two divisions. For island defense force, which is in charge of Jeju Island, Ulleung Island, Dokdo Island and five northwestern boarder island defenses, it should be in the size of one brigade. Also for standing international peace keeping operation, it requires one brigade. Therefore Marine Corps should be organized into three divisions. The result of the research yields a few policy implications when building appropriate military strength for Unified Korea. First, Unified Korea requires lower number of ground troops compared to that of current ROK(Republic of Korea) force. Second, air-sea forces should be drastically reinforced. Third, appropriate military strength of the Unified Korean military should be based on current ROK military system. Forth, building appropriate military strength for Unified Korea should start from today, not after reunification. Because of this, South Korea should build a military power that can simultaneously prepare for current North Korea's provocations and future threats from neighboring countries after reunification. The core of this research is to decide appropriate military strength for Unified Korea to realize relative balance that will ensure defense sufficiency from neighboring countries threats. In other words, this research should precisely be aware of threats posed by neighboring countries and decide minimum level of military strength that could realize relative balance in conflict situation. Moreover this research will show the path for building appropriate military strength in each armed force.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.28 no.3
• /
• pp.72-84
• /
• 2010

This study was attempted in order to offer basic data for implementing and applying Samjonseokjo(三尊石造), which is one of traditional stone construction method, by confirming how the constructive principle is expressed such as proportional beauty, which is contained in the modeling of Triad of Buddha Carved on Rock that was formed in the period of the Three States, centering on Triad of Buddha Carved on Rock in Susan. The summarized findings are as follows. 1. As a result of analyzing size and proportion of totally 17 of Triad of Buddha Carved on Rock, the average total height in Bonjonbul(本尊佛) was 2.96m. Right Hyeopsi(右挾侍) was 2.19m. Left Hyeopsi(左挾侍) was 2.16m. The height ratio according to this was 100:75:75, thereby having shown the relationship of left-right symmetrical balance. The area ratio in left-right Hyeopsi was 13.4:13.7, thereby the two area having been evenly matched. 2. The Triad of Buddha Carved on Rock in Seosan is carved on Inam(印岩) rock after crossing over Sambulgyo bridge of the Yonghyeon valley. Left direction was measured with $S47^{\circ}E$ in an angle of direction. This is judged to target an image change and an aesthetic sense in a Buddhist statue according to direction of sunlight while blocking worshipers' dazzling. 3. As for iconic characteristics of Buddha Carved on Rock in Seosan, there is even Hyeopsi in Bangasang(半跏像) and Bongjiboju(捧持寶珠) type Bosangipsang. In the face of Samjon composition in left-right asymmetry, the unification is indicated while the same line and shape are repeated. Thus, the stably visual balance is being shown. 4. In case of Triad of Buddha Carved on Rock in Seosan, total height in Bonjonbul, left Hyeopsi, and right Hyeopsi was 2.80m, 1.66m, and 1.70m, respectively. Height ratio in left-right Hyeopsibul was 0.60:0.62, thereby having been almost equal. On the other hand, the area ratio was 28.8:25.2, thereby having shown bigger difference. The area ratio on a plane was grasped to come closer to Samjae aesthetic proportion. 5. The axial angle of centering on Gwangbae was 84:46:50, thereby having been close to right angle. On the other hand, the axial angle ratio of centering on Yeonhwajwa(蓮華坐: lotus position) was measured to be 135:25:20, thereby having shown the form of inequilateral triangle close to obtuse angle. Accordingly, the upper part and the lower part of Triad of Buddha Carved on Rock in Susan are taking the stably proportional sense in the middle of maintaining the corresponding relationship through angular proportion of inequilateral triangle in right angle and obtuse angle. 6. The distance ratio in the upper half was 0.51:0.36:0.38. On the other hand, the distance ratio in the lower half was 0.53 : 0.33 : 0.27. Thus, the up-down and left-right symmetrical balance is being formed while showing the image closer to inequilateral triangle. 7. As a result of examining relationship of Samjae-mi(三才美) targeting Triad of Buddha Carved on Rock in Susan, the angular ratio was shown to be more notable that forms the area ratio or triangular form rather than length ratio. The inequilateral triangle, which is formed centering on Gwangbae(光背) in the upper part and Yeonhwajwa(lotus position) in the lower part, is becoming very importantly internal motive of doubling the constructive beauty among Samjae, no less than the mutually height and area ratio in Samjonbul.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.39 no.1
• /
• pp.15-26
• /
• 1994

To understand the relative contribution of varietal and environmental variation on various grain quality components in rice, grain appearance, milling recovery, several physicochemical properties of rice grain and texture or palatability of cooked rice for milled rice materials of seven cultivars(five japonica & two Tongil-type), produced at six locations of the middle and southern plain area of Korea in 1989, were evaluated and analyzed the obtained data. Highly significant varietal variations were detected in all grain quality components of the rice materials and marked locational variations with about 14-54% portion of total variation were recognized in grain appearance, milling recovery, alkali digestibility, protein content, K /Mg ratio, gelatinization temperature, breakdown and setback viscosities. Variations of variety x location interaction were especially large in overall palatability score of cooked rice and consistency or set- back viscosities of amylograph. Tongil-type cultivars showed poor marketing quality, lower milling recovery, slightly lower alkali digestibility and amylose content, a little higher protein content and K /Mg ratio, relatively higher peak, breakdown and consistency viscosities, significantly lower setback viscosity, and more undesirable palatability of cooked rice compared with japonica rices. The japonica rice varieties possessing good palatability of cooked rice were slightly low in protein content and a little high in K /Mg ratio and stickiness /hardness ratio of cooked rice. Rice 1000-kernel weight was significantly heavier in rice materials produced in Iri lowland compared with other locations. Milling recovery from rough to brown rice and ripening quality were lowest in Milyang late-planted rice while highest in Iri lowland and Gyehwa reclaimed-land rice. Amylose content of milled rice was about 1% lower in Gyehwa rice compared with other locations. Protein content of polished rice was about 1% lower in rice materials of middle plain area than those of southern plain regions. K/Mg ratio of milled rice was lowest in Iri rice while highest in Milyang rice. Alkali digestibility was highest in Milyang rice while lowest in Honam plain rice, but the temperature of gelatinization initiation of rice flour in amylograph was lowest in Suwon and Iri rices while highest in Milyang rice. Breakdown viscosity was lowest in Milyang rice and next lower in Ichon lowland rice while highest in Gyehwa and Iri rices, and setback viscosity was the contrary tendency. The stickiness/hardness ratio of cooked rice was slightly lower in southern-plain rices than in middle-plain ones, and the palatability of cooked rice was best in Namyang reclaimed-land rice and next better with the order of Suwon$\geq$Iri$\geq$Ichon$\geq$Gyehwa$\geq$Milyang rices. The rice materials can be classified genotypically into two ecotypes of japonica and Tongil-type rice groups, and environmentally into three regions of Milyang, middle and Honam lowland by the distribution on the plane of 1st and 2nd principal components contracted from eleven grain quality properties closely associated with palatability of cooked rice by principal component analysis.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.39 no.1
• /
• pp.27-37
• /
• 1994

To catch the relative importance of varietal and environmental variation in various grain quality components associated with palatability of cooked rice, grain appearance, milling recovery, several physicochemical properties of milled rice and texture or eating quality of cooked rice for rice materials of five japonica cultivars, produced at four locations of the mid-mountainous and alpine area of Korea in 1989, were evaluated and analyzed the obtained data. Highly significant varietal and locational variations were detected in 1000-grain weight, amylose content, K/Mg ratio, gelatinization temperature, peak viscosity, breakdown and setback viscosities as compared with variety x location interaction variation. Also, marked locational variations were recongnized in milling recovery from rough to brwon rice, alkali digestibility and protein content, and significant varietal variation was caught in stickiness /hardness ratio of cooked rice. The variety x location interaction variation was especially large in quality components of grain appearance and ripening, palatability of cooked rice and consistency viscosity. One thousand kernel weight was heaviest in Jinbuolbyeo and Odaebyeo, and the unfilled grain ratio was lowest in Jinbuolbyeo. Odaebyeo showed slightly' lower ratio of intact and clear milled rice because of more chalky rice kernels compared with other cultivars. Amylose content of Jinbuolbyeo and Sobaegbyeo was about 1% lower than that of others and K/Mg ratio of Odaebyeo was the lowest one among rice materials. Odaebyeo, Sobaegbyeo and Jinbuolbyeo revealed significantly low gelatinization temperature and setback viscosity while high peak and breakdown viscosities. Cholwon rice showed the greatest kernel weight, good grain filling but lowest ratio of intact and clear milled rice while Jinbu rices exhibited the highest milling recovery from rough to brown rice and ratio of sound milled rice. Amylose content of milled rice in Jinbu rices was about 2-3% lower than those in other locations. Protein content of polished rice was about 1% lower in rice materials of middle zone than those of southern part of Korea. K/Mg ratio of milled rice was highest in Jinbu rice and potassium content was slightly higher in the rice materials of middle region than in those of southern region. Alkali digestion value and gelatinization temperature of polished rice was markedly high in Jinbu rices as compared with other locations. Breakdown viscosity was hightest in Chlown rices and next higher with the order of Hwaso>Unbong>Jinbu rices, and setback viscosity was the quite contrary tendency with breakdown. The stickiness /hardness ratio of cooked rice was relatively higher value in Cholwon rices than in the others and the palatability of cooked rice was a little better in Unbong and Cholwon rices than in Jinbu and Hwaso rices, although variety x location interaction variation was large. The rice materials can be classified largely into two groups of Jinbu and the others by the distribution on the plane of 1st and 2nd principal components (about 60% of total informations) contracted from twelve grain quality properties closely associated with eating quality of cooked rice. Also, Jinbu and the other rices were divided into two and three rice groups respectively. Varietal variation of overall rice quality was smallest in Hwaso. The most superior rice group in overall quality evaluation included Odaebyeo produced at Cholwon, Unbong and Hwaso, and Sobaegbyeo grown at Unbong

• Journal of Chest Surgery
• /
• v.41 no.6
• /
• pp.703-709
• /
• 2008

Background: Diagnosis and treatment are often successful in the setting of cardiac myxomas. However, cardiac myxomas can lead to catastrophic complications, due to intracardiac obstruction and embolism preoperatively, and can recur postoperatively. Material and Method: We retrospectively reviewed the clinical characteristics, surgical treatment, and recurrence data of 85 patients who underwent cardiac myxoma surgery at Asan Medical Center between November 1994 and June 2007. We analyzed the morphologic characteristics of 58 patients with left atrial myxomas and determined the development of functional mitral valve stenosis and systemic embolism through reviewing the results of preoperative echo-cardiograms to find potential preoperative risk factors. Result: Twenty-seven (31.8%) patients were men, and 58 (68.2%) were women. The mean patient age was $54.5{\pm}14.3$ years. Preoperative symptoms included obstructive symptoms in 41 (48.2%) patients, signs of embolism in 19 (22.4%), constitutional symptoms in 8 (9.4%), and no symptoms in 19 (20.0%). Among the 58 patients with left atrial myxomas, the mean maximal tumor diameter was $4.3{\pm}1.8$ (range $1.1{\sim}8\;cm$)cm. Twenty-six (44.8%) patients had a prolapsing type, defined as a tumor mobile enough to move down. to the mitral. annular plane during diastole, and 32 (55.2%) had villous type, defined as a tumor consisting of multiple fine villous extensions on the surface. Twelve (20.7%) patients had severe functional mitral valve stenosis, and 15 (25.9%) had systemic embolism preoperatively. The incidence of severe functional mitral valve stenosis was significantly higher in patients with the prolapsing type than in those with the non-prolapsing type (p=0.001). The mean maximal tumor diameter in patients with severe functional mitral valve stenosis was $5.1{\pm}1.0\;cm$, significantly larger than that seen in patients without severe functional mitral valve stenosis (p=0.041). The incidence of systemic embolism was significantly higher in patients with the villous type than in those with the smooth type (p=0.006). Postoperative complications were noted in 6 (7.1%) patients, and early mortality was noted in 1 (1.2%). The mean postoperative follow-up duration was $36.2{\pm}37.5$ months, with recurrence reported in 2(2.4%) patients during the follow-up period. The disease free interval were 48, 12 months, respectively. Conclusion: Surgical treatment for cardiac myxomas was performed safely, and long-term prognosis was good. In patients with left atrial myxoma, close attention should be maintained and surgery should be performed promptly in those of prolapsing type, those with large maximal diameter in order to prevent severe functional mitral valve stenosis, and those of villous type in order to prevent systemic embolism. Echocardiography should be followed serially in order to detect recurrence.

• Progress in Medical Physics
• /
• v.18 no.3
• /
• pp.118-125
• /
• 2007

In this study we estimated a geometric correlation among digitally reconstructed radiographic image (DRRI), kV x-ray image (kVXI) from the On-Board Imager (OBI) and electric portal image (EPI). To verify geometric correspondence of DRRI, kVXI and EPI, specially designed phantom with indexed 6 ball bearings (BBs) were employed. After accurate setup of the phantom on a treatment couch using orthogonal EPIs, we acquired set of orthogonal kVXIs and EPIs then compared the absolute positions of the center of the BBs calculated at each phantom plane for kVXI and EPI respectively. We also checked matching result for obliquely incident beam (gantry angle of $315^{\circ}$) after 2D-2D matching provided by OBI application. A reference EPI obtained after initial setup of the phantom was compared with 10 series of EPIs acquired after each 2D-2D matching. Imaginary setup errors were generated from -5 mm to 5 mm at each couch motion direction. Calculated positions of all center positions of the BBs at three different images were agreed with the actual points within a millimeter and each other. Calculated center positions of the BBs from the reference and obtained EPIs after 2D-2D matching agreed within a millimeter. We could tentatively conclude that the OBI system was mechanically quite reliable for image guided radiation therapy (IGRT) purpose.

• The Journal of Korean Academy of Prosthodontics
• /
• v.55 no.4
• /
• pp.381-388
• /
• 2017

Purpose: Unpredictable shrinkage of zirconia during sintering process causes discrepancy. Therefore, there have been attempts to reduce discrepancy by milling zirconia after sintering. However, due to the hardness of sintered zirconia, milling takes longer time, causes damage to the machine and causes chip formation. With customized zirconia block using the mean dimension of prepared natural dentition, it is expected to overcome these shortcomings. Materials and methods: The mean dimension of prepared natural dentition was analyzed as STL file after scanning of prepared teeth treated at SNUDH. The transverse, frontal and sagittal planes were set using Mimics and Photoshop. 3D volume was projected on each plane, and the outer line was measured through external tangent line, and the inner line was measured through inflection point of tangent line. Results: The mean height of prepared incisal (N = 57) is $6.60{\pm}1.05mm$, mesiodistal length is $2.98{\pm}0.73mm$, buccolingual length is $2.04{\pm}0.73mm$. The mean height of prepared premolar (N = 15) is $5.37{\pm}1.49mm$, mesiodistal length is $4.10{\pm}1.78mm$, buccolingual length is $5.86{\pm}1.55mm$. And the mean height of prepared molar (N = 13) is $5.11{\pm}1.29mm$, mesiodistal length is $6.80{\pm}1.18mm$, buccolingual length is $7.34{\pm}1.40mm$. Conclusion: Using the mean dimension of prepared natural dentition, it is expected to be able to fabricate customized zirconia block.