• Physical Therapy Korea
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• v.17 no.3
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• pp.20-30
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• 2010

This study examined whether any changes by mental task types on postural control in chronic stroke persons. Sixteen chronic stroke persons (mean age=53.75 yr) and sixteen age-and gender-matched healthy controls (mean age=54.44 yr) took part in this study. Participants randomly performed three different tasks on the stable and unstable surfaces. The no mental task was to stand while holding a 100 g weight in each hand, the arithmetic task (mental task) was to perform a silent 1-backwards counting while standing and holding a 100 g weight in each hand, and the simple task (mental task) was to stand and hold with both hands a tray (200 g) on which a glass filled with water has been placed. Sway path and sway velocity of the center of pressure (COP) were measured to assess standing postural control by task performance using the force platform. According to the results, in stroke group, total sway path and total sway velocity of COP was significantly decreased during arithmetic and simple task compared to no mental task on the stable surface (p<.05), and sway path (anteroposterior AP, mediolateral ML) of COP, total and sway velocity (AP, ML, total) of COP was significantly decreased during arithmetic and simple task compared to no mental task on the unstable surface (p<.05). Especially, sway path (AP, total) of COP and sway velocity (AP, ML, total) of COP was significantly decreased under the simple task when compared to the arithmetic task on the unstable surface (p<.05). In healthy control group, sway path (AP, ML, total) of COP and sway velocity (AP, ML, total) of COP was significantly decreased during arithmetic and simple task compared to no mental task on the stable and unstable surface (p<.05), and sway path (AP, total) of COP and sway velocity (AP, ML, total) of COP was significantly decreased under the simple task when compared to the arithmetic task on the unstable surface (p<.05). In conclusion, the findings of this study showed that arithmetic and simple task improved standing postural control for chronic stroke patients and the type of arithmetic and simple tasks were critical factor that reduced standing postural sway in dual-task conditions. Future research should determine whether dual-task conditions, including simple task, would be effective as a training program for standing postural control of stroke patients.

• Progress in Medical Physics
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• v.12 no.2
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• pp.155-160
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• 2001

We developed a new method that the radiation field shape and intensity could be controlled automatically with a insertion of the liquid shielding material box having a rotatable model imitated the 3-dimensional target volume within. The molded box filled with the mercury was mounted to the tray. A acrylic model imitated the 3-dimensional target volume was fixed into the center of the interior of the box. Although the gentry rotate, the acrylic model can be returned to the original direction of the target due to the action of the gravity. The film measurements at the gantry rotation angle 0$^{\circ}$, 45$^{\circ}$, and 90$^{\circ}$, respectively were shown that the radiation intensities were modulated properly and the field shapes were conformed to the target. We verified the dose distribution for our method with a cylindrical acrylic phantom inserted a film within. In the case of the 8-field irradiation, the 80% isodose line was enclosed the target shape properly. This results show the realization of a new intensity-modulated radiation therapy(IMRT).

• The Korean Journal of Mycology
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• v.31 no.1
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• pp.22-27
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• 2003

This research aimed at developing the efficient method and device applicable to the inoculation of mushroom using (spawn was intended to utilize) liquid spawn for the stable production of mushroom. For the mass production of liquid culture, optimal inoculum volume and cultural period were $5{\sim}6%$ and 4 days for Flammulina velutipes and 4% and 5 days for Pleurotus ostreatus. Fruit body weight in 850 ml polythene bottle was highest at 6% or 15 ml liquid inoculum for P. ostreatus and $4{\sim}6%$ or $10{\sim}15ml$ for F. velutipes. Weight of fruit body by the application of liquid spawn inoculation system increased up to 33.7% for P. ostreatus and 32.8% for F. velutipes, respetively, compared to conventional spawn making system. The system of liquid spawn inoculation was successfully operated without malfunction in opening or closing the lid, and it took 26 min to inoculate 1200 bottles.

• Restorative Dentistry and Endodontics
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• v.27 no.3
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• pp.249-256
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• 2002

The use of flowable composite resins as liners in class II packable composite restoration has been suggested by some manufacturers. However, the contributions of this technique are unproven. The purpose of this study was to compare the gingival microleakage in class II packable composite restorations with or without the use of flowable composite resins as liners. Slot cavities were prepared on both proximals of 80 extracted human molars and randomly assigned to 8 groups of 20 each. The gingival margins were located at 1mm above CEJ in 80 cavities (group1-4) and 1mm below CEJ in 80 cavities (group5-8). The prepared teeth were mounted in the customized tray with adjacent teeth to simulate clinical conditions and metallic matrix band (Sectional matrix) and wooden wedges were applied. After acid etching and application of Single Bond, each group was restored with the following materials using incremental placement technique: Group 1,5 (Filtek P60), group 2, 3, 4 and group 6, 7, 8 (AeliteFlo, TetricFlow, Revolution/ Filtek P60). All specimens were thermocycled 500 times between 5$^{\circ}C$ and 55$^{\circ}C$ with 1 mimute dwell time, immersed 2% methylene blue dye for 24 hours and then rinsed with tab water. The specimens were embedded in clear resin and sectioned longitudinally through the center of restoration with a low speed diamond saw. Dye penetration at gingival margin was viewed at 20 magnification and analyzed on a scale of 0 to 4. Kruscal-Wallis One way analysis and Mann-Whitney Rank sum test were used to analyze the results. The results of this study were as follows. 1. The leakage values seen at the enamel margin were significantly lower than those seen at the dentin margin(P<0.05). 2. On the enamel margin, packable composite resins with flowable liners showed lower leakage than those without flowable liners, but there were no significant differences among the four groups(P>0.05). 3. On the dentin margin, four groups demonstrated moderate to severe leakage, and there were no significant differences in leakage values(P>0.05).

• Restorative Dentistry and Endodontics
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• v.31 no.6
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• pp.470-476
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• 2006

The objective of this in situ study was to evaluate the effects of whitening strip (Claren, LG Household & Health Care Ltd, 2.6% hydrogen peroxide) and gel (Opalescence, Ultradent, 10% carbamide peroxide) on microhardness of enamel in comparison with untreated control. Extracted twenty human upper incisors were disinfected, cleaned, and labial side of each incisor sectioned into 3 fragments by 2 ${\times}$ 2 mm size. After sectioning, labial sides of fragments were flattened and fixed to orthodontic bracket using flowable composite resin. Specimens prepared from each tooth were attached to the labial side of upper incisors of twenty volunteers one by one and treated by three different methods: (1) untreated control (2) treated with whitening strip for 14 days (3) treated with whitening gel for 14 days. Microhardness (Microhardness tester, Zwick) of each specimen was measured at the baseline of pre-treatment, immediate after bleaching treatment, 14 days after bleaching treatment and Knoop Hardness Number was determined. Microhardness changes of experimental groups were compared. The results show that tooth whitening strip and gel used in this study does not effect the microhardness of enamel during bleaching procedure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.216-220
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• 2002

The microbiological examinations of food service operations were conducted for the hygienic evaluation at four elementary schools in Busan, Korea. Total one hundred and seventy two swabbed samples using sponge were collected from the surface of environments, utensils and equipments of food service facilities and analyzed by measuring the total, coliform and psychrotrophic count. Sampling sites were the surfaces of floors, drains, walls, knives, cutting boards, rubber gloves, vinyl aprons, plastic containers, carriers, shelves, trays, dry shelves, electric tray dryer, food containers, soup containers, rice cookers, frying pans, boiling cookers, refrigerators, dumb waiters and dishwashers. The swabbed samples kept in an ice-parked box were transported to a laboratory and analyzed. The results demonstrated that the degree of contamination depended on the sampling sites. Averages of total counts of surface swab samples were ranged from 0.62 to 7.79 Log CFU/200 cm$^2$. The level of coliforms were ranged from not detectable to 5.26 Log CFU/200 cm$^2$, and those of psychrotrophs from not detectable to 6.15 Log CFU/200 cm$^2$. The severely contaminated sites were dumb waiters, drains, rice cookers, knives, plastic containers and floors. Also cutting boards, rubber gloves, carriers, drying shelves, vinyl aprons, boiling cookers, soup containers, frying pans and refrigerators were highly contaminated with the level of abode 3.5 Log CFU/200 cm$^2$. Therefore, those sites should be focused and controlled according to control points of sanitation standard operating procedures (SSOP). Also, periodic microbiological examination in addition to visual examination is recommended on these highly contaminated sites indicated above results at food service operations in elementary school.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.191-203
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• 2005

Statement of problem. In Korea, the preliminary impression trays for dental and edentulous maxillae are manufactured on the base of the statistical value of Westerners. There had been less study on the dental and edentulous arches of Koreans. Purpose. The purpose of this study was to evaluate an average dental cast, preliminary impression trays, three-dimensional relation of dental and edentulous maxilla of Koreans Material and methods. The subjects for this study were 173 dental casts of maxilla (dental: 52, edentulous : 146) with ages $18\{\sim}60$ years old. Each of the master casts was measured 69 measuring points on the dental cast or maxilla, and 46 measuring points on the edentulous cast of maxilla with three-dimensional digital measuring machine. Each measuring points were analysed and were overlapped, that three dimensional dental graphic manufactured by CAD/CAM system. Results. 1. A standard of distribution to alveolar bone were width between left and right buccal border lines of the standard 3/4 line. The mean value of dental and edentulous casts were 67.27mm, 63.49mm respectively. 2. Morphological classification of dental casts were divided into three groups or V-shape, O-shape, U-shape, that proportion of distribution were 17%, 16%, 67%, respectively. Dimensional classification of the dental casts were divided into five groups of less than 63mm, 63 up to 65mm, 65 up to 67mm. 67 up to 69mm, more than 69mm, respectively. 3. Morphological classification of edentulous casts were divided into three groups or V-shape, O-shape, U-shape, that proportion of distribution were 18%, 17%, 65%, respectively Dimensional classification of the edentulous casts were divided into five groups of less than 57mm, 57 up to 61mm, 61 up to 65mm, 65 up to 69mm, more than 69mm, respectively. 4. Mean dental and edentulous cast of maxilla were overlapped, the proportion of bone resorption to alveolar bone is higher than that of palatal bone, its difference were higher anterior 2/4 area than posterior 3/4 area. Conclusion. It obtains information of preliminary impression trays for dental and edentulous maxilla of Koreans.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.1
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• pp.73-89
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• 1991

Impression ragistration is an improtant and difficult phase of prosthodontic treatment procedures and a tray of appropriate size and shape is essential to obtain the accurate impression. Particularly, in edentulous patients, the size and forms of their residual alveolar ridges are different from one another. Therefore, in this study, various measurements were taken on the edentulous models. And the measurements were analyzed and compared with one another. The results were as follows ; 1. The mean of denture bearing area was $32.86cm^2$ in the upper jaws, $24.20cm^2$ in the lower jaws and the variation of denture bearing area was greater in the upper than in the lower jaws and in males than in females. 2. The mean of A-P(anteroposterior) ridge length was 48.72mm in the upper jaws, 53.05mm in the lower jaws and that of males was longer than that of females. 3. The mean of most posterior ridge width was 47.23mm in the upper jaws, 58.03mm in the lower jaws and the difference of that between males and females was least in both jaws. 4. In the upper jaws, the mean of ridge width was 29.66mm on anterior 1/4, 42.79mm on middle, 48.95mm on posterior 1/4 line and the mean of palatal height was 4.56mm on anterior 1/4, 10.01mm on middle, 10.84mm on posterior 1/4 line. 5. In the lower jaws, the mean of ridge width was 33.24mm on anterior 1/4, 50.19mm on middle, 59.16mm on posterior 1/4 line and the mean of lingual ridge height was 5.49mm on anterior 1/4, 9.16mm on middle, 16.72mm on posterior 1/4 line. 6. The correlation coefficient(=r) between denture bearing area and A-P ridge length was 0.83 in the upper jaws and 0.75 in the lower jaws. The corelation between denture bearing area and AP ridge length was statistically significant, but, between denture bearing area and A-P ridge length and between A-P ridge length and the most posterior ridge width was not statistically significant in both jaws. 7. Alveolar ridge forms were classified into three(ovoid, "u" shape, and "v"shape) categories. In the upper jaws, ovoid was 66%, "u" shape was 24%, and "v" shape was 10%, in the lower jaws, ovoid was 66.7%, "u" shape was 20%, and "v" shape was 13.3%.

• Progress in Medical Physics
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• v.13 no.1
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• pp.1-8
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• 2002

Accurate knowledge of the distribution of contamination electrons ( which comes from mainly gantry head by Compton scattering, pair production, and tray: henceforth called leptons ) at the surface and in the first centimeters of tissue is essential for the clinical practice of radiation oncology. Such lepton tends to reduce or eliminate the ‘skin-sparing’ advantage of megavoltage photon beam radiotherapy, This information is needed to prescribe a absorbed dose to a skin volume at a few millimeter depth in high energy therapeutic radiation photon beam All experiments were done with 15 MV photon beam from a dual energy linear accelerator (Clinac 1800, Varian). Field size is defined by ranged from 10.0$\times$10.0 to 30.0$\times$30.0 $\textrm{cm}^2$. The absorbed dose and distribution of leptons in therapeutic radiation beam (15 MV) are investigated by means of variable blocked beams of 30.0$\times$30.0 $\textrm{cm}^2$ and dose beam profiles partly removed leptons with a copper plate. A numerous leptons mainly are distributed as shape of broad cone in the central photon beam and leptons path length in the water are shorter than 2.5 cm because of the leptons energy having around 3.0 MeV. These results clearly appears that the subtraction of leptons from the total depth dose curve not only lower the absolute dose in the buildup region and surface dose, it also causes a shift of d$_{max}$ to a deeper depth.

• Journal of Agricultural Extension & Community Development
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• v.3 no.1
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• pp.17-41
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• 1996

In the situation of rapid industrialization based on the lopsided development of economy since 1960, Korean rural society has faced a crisis of disruption. As a result, the civilian government has tried a few actions to change the circumstance. However, it is said that the coral polices were not satisfactory. Those who were concerned with the rural problems of these days argue that it is necessary to adopt new policies and further to change the policymakers` philosophies concerning the matter. The arguments are certainly based on the beliefs that the sound policies come from the sound philosophies. This study aims to analyze the existing rural polices and their policymakers` philosophies and to design of a new paradigm. For the purpose, this study was set there specific objectives: First, to overview the moor points of Quantitative Utilitarianism of Jeremy Bentham and the Social Justice Theory of John Rawls, the contrasting frameworks of the moral philosophies; Second, to trace the major or trade of the rural policies since 1960s in Korea; Third, to analyze the policymakers` philosophies reflected on the rural policies; Fourth, to design a new paradigm of the rural policies. This study mainly adopted descriptive method based on the various source of government and non-government statistics, white papers and other researches. The major findings of this study may be summarized as follows: 1. The historical epochs of the rural policies in Korea was divided into the periods: (1) An organizational and institutional establishment for self-reliance of main crops and the New Village Movement $(1969{\sim}70)$; (2) An initiation of `open-door` policies to the foreign farm products $(1970{\sim}80)$; (3) Completion of the UR meetings and the recommendations of the Rural and Fishery Development Commission (1980-present). 2. It was found that the philosophical foundations of coral policies were directly reflected from the utilitarianism of the national development. Under the philosophy it was the modem sector of economy that was to spearhead the national development, and the rural sector was situated to the peripheral position and hardly in the spot-light. Therefore, it may be said that the present situation of the rural society was largely rooted in the model of economic development. 3. As a new direction of the coral policies, many studies were focussing on the NTC (non-trade concerns) functions of agriculture for the present and future society. The researchers argue that the cost of protecting and supporting agriculture and rural society may be higher than that of the burden which the nation should be bear in the case of failure of agriculture. Although it tray be true, however, it should be noted that the argument is another type of utilitarianism which prevailed in the past. As a philosophy of rural policies, utilitarianism is straight forward and persuasive, however, it has also limitations in terms of relativism in broad sense or social justice in specific manna. 4. This study suggests to set the philosophical foundations of rural policies on the basis of Rawl`s Theory of Justice mentioned earlier. It emphasizes the inviolability of social justice which was neglected for the national benefits timing the period of development dictatorship in 1960s and 1970s. The principles of social justice for coral people were identified as twofold; (1) The principle of the t equal liberty; (2) (a) Difference principle, (b) The principle of fair equality of opportunity.