• Progress in Medical Physics
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• v.8 no.2
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• pp.45-57
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• 1997

It is mandatory to measure accurately the dose distribution and the total absorbed dose of fast neutron for putting it to the clinical use. At present the methods of measurement of fast neutron are proposed largely by American Associations of Physicists in Medicine, European Clinical Neutron Dosimetry Group, and International Commission on Radiation Units and Measurements. The complexity of measurement, however, induces the methodological differences between them. In our study, therefore, we tried to establish a unique technique of measurement by means of measuring the emitted doses and the dose distribution of fast neutron beam from neutron therapy machine, and to invent a standard method of measurement adequate to our situation. For measuring the absorbed doses and the dose distribution of fast neutron beam, we used IC-17 and IC-18 ion chambers manufactured by A-150 plastic(tissue-equivalent material), IC-17M ion chamber manufactured by magnesium, TE gas and Ar gas, and RDM 2A electrometer. The magnitude of gamma-contamination intermingled with fast neutron beam was about 13％ at 5cm depth of standard irradiated field, and increased as the depth was increased. At the central axis the maximum dose depth and 50％ dose depth were 1.32cm and 14.8cm, respectively. The surface dose rate was 41.6-54.1％ throughout the entire irradiated fields and increased as the irradiated fields were increased. Beam profile was that the horn effect of about 7.5％ appeared at 2.5cm depth and the flattest at 10cm depth.

• Journal of Gastric Cancer
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• v.13 no.1
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• pp.51-57
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• 2013

Purpose: Additional gastrectomy is needed after endoscopic resection for early gastric cancer when pathology confirms any possibility of lymph node metastasis or margin involvement. No studies depicted the optimal type of surgery to apply in these patients. We compared the short-term and long-term outcomes of laparoscopic gastrectomy with those of open gastrectomy after endoscopic resection to identify the optimal type of surgery. Materials and Methods: From 2003 to 2010, 110 consecutive patients who underwent gastrectomy with lymphadenectomy either by laparoscopic (n=74) or by open (n=36) for gastric cancer after endoscopic resection were retrospectively analyzed. Postoperative and oncological outcomes were compared according to types of surgical approach. Results: Clinicopathological characteristics were comparable between the two groups. Laparoscopic group showed significantly shorter time to gas passing and soft diet and hospital day than open group while operation time and rate of postoperative complications were comparable between the two groups. All specimens had negative margins regardless of types of approach. Mean number of retrieved lymph nodes did not differ significantly between the two groups. During the median follow-up of 47 months, there were no statistical differences in recurrence rate (1.4% for laparoscopic and 5.6% for open, P=0.25) and in overall (P=0.22) and disease-free survival (P=0.19) between the two groups. Type of approach was not an independent risk factor for recurrence and survival. Conclusions: Laparoscopic gastrectomy after endoscopic resection showed comparable oncologic outcomes to open approach while maintaining benefits of minimally invasive surgery. Thus, laparoscopic gastrectomy can be a treatment of choice for patients previously treated by endoscopic resection.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.3
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• pp.226-234
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• 2020

As the average life expectancy of human beings is extended in addition to the entry of the aging society, there is a tendency for the interest in the appearance of men and women in modern society to increase. The most external judgment of human aging is the wrinkles on the facial skin. People are undergoing various procedures to have clean, wrinkled, and resilient healthy skin. Many thread lifting procedures are being implemented because they tend to want simple and effective procedures during the procedure. In this study, in order to improve lifting effect in thread lifting, animal experiments were conducted to confirm the improvement of wrinkles by injecting RF high frequency and CO₂ gas into existing PDO suture procedures. The experimental groups consisted of natural aging groups, PDO treatment groups, groups with RF high frequency in PDO procedures, groups with CO₂ gas injected into PDO procedures, and groups with CO₂ gas and RF injected simultaneously into PDO procedures. The individuals in the natural aging group had an average wrinkle depth of 0.408mm before the procedure, and the average wrinkle depth of the 10th week was 0.68mm. The depth of wrinkles in the PDO treatment group averaged 0.384mm before the procedure, and 0.348mm on the 10th week after the procedure. The average crease depth of pre-procedure objects injected with RF high frequency in PDO was 0.42mm, and the average crease depth for 10 weeks was 0.378mm. The average crease depth of the CO₂ gas injected into the PDO was 0.4mm before the procedure, and the average crease depth was reduced to 0.332mm in the 10th week after the procedure. On average, the number of objects injected with CO₂ gas and RF high frequency in the PDO procedure decreased to 0.412mm before and 0.338mm in the 10th week after the procedure. The procedure of injecting CO₂ gas and RF into the PDO suture showed the highest reduction rate of 17.96%.

• Journal of Magnetics
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• v.10 no.1
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• pp.10-13
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• 2005

We have studied effects of the partial substitution of $La^{3+}$ for $A^{2+}$ on the magnetic properties of double perovskites $A_2FeMoO_6$ (A=Ca, Sr and Ba). Polycrystalline $A_{2-x}La_xFeMoO_6(0{\leq}x{\leq}0.2)$ samples have been prepared by the conventional solid-state reaction in a stream of 5% $H_2$/Ar gas. The x-ray data indicate that A=Ca is monoclinic with the space group P$2_1$/n, A=Sr is tetragonal with the space group I4/mmm, and A=Ba is cubic with the space group Fm3m. The substitution of $La^{3+}$ for $A^{2+}$ results in a cell volume increase for A=Ca and a cell volume reduction for A=Ba. The decrease of saturation magnetization with increasing x arises from the reduction of magnetic moment associated with the electron doping and the disorder at the Fe and Mo sites. The partial substitution of magnetic $La^{3+}$ for $A^{2+}$ considerably enhances the Curie temperature $T_c$ from 316 K for x = 0 to 334 K for x = 0.2. This enhancement of $T_c$ with $La^{3+}$ doping originates from electron doping effects in addition to ionic size ones.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.106-114
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• 2006

Purpose : Studying the serotypes and emm genotype of group A streptococci(GAS) hold a key role in the investigation of epidemiology, pathogenesis, and resistance to antibiotics. We planed to find out the possible differences in serotypes and genotypes between the invasive and the non-invasive GAS infection. Methods : We obtained 39 isolates from the patients hospitalized in 2004 with the diagnosis of invasive GAS infectious diseases in the Severance Hospital, Yonsei University. We sent the isolates to the WHO Collaboratory Center in University of Minnesota and analyzed T serotypes and emm genotypes. These results were compared with non-invasive GAS infections in our hospital. Results : Compared this data with the results of 2003 to 2004, T2/28, T3, T5/27/44, T9 and NT were more prevalent. The NT showed statistically significant difference(P=0.019). The emm 3, emm 9, emm 18, emm 44 and emm provision type STG485 were more frequent genotypes compared with the study in 2003~2004, relatively. The emm provision type STG485 had statistically significant difference(P=0.000). The incidence of T12 plus T4, known as erythromycin(EM) resistant serotypes, was as low as 17.9% in this study, compared with those of non-invasive strains. Conclusion : The incidence of EM-resistant strains is supposed not to be higher in invasive GAS infection. We could find out possible higher incidence of rheumatogenic strains in the invasive GAS infections. It seems to be important to have an effort on studying of serotyping and genotyping for the monitoring of strains and to know the epidemiologic characteristics.

• The Journal of Korean Academy of Sensory Integration
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• v.11 no.2
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• pp.13-26
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• 2013

Objective : The purpose of the study was to investigate The effects of the sensory integration intervention focused on combined both individual therapy and group therapy for sensory integration ability and occupational performance abilities in children with somatodyspraxia. Methods : Once in a total of 12 weeks, baseline period of four sessions and twenty-four session intervention period, research process had combined individual therapy and group therapy for sensory integration therapy. The Design is ABA design of single-subject research design. For a comparison of each-side of the operation performance change in therapy for children, through the assessment Baseline at four sessions and reassessment at two sessions after intervention, the Occupational performance ability change was measured. During intervention period, Process changed the Sensory Integration ability was measured through the Goal Attainment Scale (GAS). Results : The Sensory Integration Ability combined Individual therapy and Group therapy have effect about improvement of the Sensory Integration ability and the Occupational performance ability for children with Somatodyspraxia. Conclusion : Henceforth, subject will undergo systematized experimental design, and when dependent variable such as Sensory Integration ability and the Occupational performance was measured, effect-measuring study needs through using reliable tools.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.39.1-39.1
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• 2014

We present the results of our analysis of the RR Lyrae (RRL) variable stars detected in two transition-type dwarf galaxies (dTrans), ESO294-G010 and ESO410-G005 in the Sculptor group, which is known to be one of the closest neighboring galaxy groups to our Local Group. Using deep archival images from the Advanced Camera for Surveys (ACS) onboard the Hubble Space Telescope (HST), we have identified a sample of RR Lyrae candidates in both dTrans galaxies [219 RRab (RR0) and 13 RRc (RR1) variables in ESO294-G010; 225 RRab and 44 RRc stars in ESO410-G005]. The metallicities of the individual RRab stars are calculated via the period-amplitude-[Fe/H] relation derived by Alcock et al. This yields mean metallicities of <[Fe/H]>_{ESO294} = -1.77 +/- 0.03 and <[Fe/H]>_{ESO410} = -1.64+/- 0.03. The RRL metallicity distribution functions (MDFs) are investigated further via simple chemical evolution models; these reveal the relics of the early chemical enrichment processes for these two dTrans galaxies. In the case of both galaxies, the shapes of the RRL MDFs are well-described by pre-enrichment models. This suggests two possible channels for the early chemical evolution for these Sculptor group dTrans galaxies: 1) The ancient stellar populations of our target dwarf galaxies might have formed from the star forming gas which was already enriched through "prompt initial enrichment" or an "initial nucleosynthetic spike" from the very first massive stars, or 2) this pre-enrichment state might have been achieved by the end products from more evolved systems of their nearest neighbor, NGC 55.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.10
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• pp.1449-1453
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• 2015

The objective of the present study was to determine the effects of feeding pelletized broccoli byproducts (PBB) on milk yield and milk composition in dairy cows. In Trial 1, an in vitro gas test determined the optimal replacement level of PBB in a concentrate mixture in a mixed substrate with Chinese wild ryegrass hay (50:50, w/w) at levels of 0, 10%, 20%, 30%, or 40% (dry matter basis). When the concentrate was replaced by PBB at a level of 20%, no adverse effects were found on the gas volume or its rate constant during ruminal fermentation. In trial 2, 24 lactating cows (days in milk = $170.4{\pm}35$; milk yield = $30{\pm}3kg/d$; body weight = $580{\pm}13kg$) were divided into 12 blocks based on day in milk and milk yield and randomly allocated to two dietary treatments: a basic diet with or without PBB replacing 20% of the concentrate mixture. The feeding trial lasted for 56 days; the first week allowed for adaptation to the diet. The milk composition was analyzed once a week. No significant difference in milk yield was observed between the two groups (23.5 vs 24.2 kg). A significant increase was found in milk fat content in the PBB group (p<0.05). Inclusion of PBB did not affect milk protein, lactose, total solids or solids-not-fat (p>0.05). These results indicated that PBB could be included in dairy cattle diets at a suitable level to replace concentrate mixture without any adverse effects on dairy performance.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.2
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• pp.207-218
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• 2017

Improving fuel consumption, particularly that of commercial vehicles, has become a global concern. The reduction in logistics cost has been a key issue in efforts to improve fuel economy and efficiency of transportation equipment. Typical technologies for reducing reduce fuel usage include air resistance reduction technologies, tire rolling resistance technologies, and idle technologies among others. Air resistance technology is a highly effective method that can be easily applied in a short period. As with air resistance technology, several devices involving side skirt, boat tail and gap fairing have been developed based on an analytical 3-D modeling technique for reducing air resistance attributed to the vehicle configuration. The devices were on a 45 feet tractor-trailer and the emission test was done using PEMS equipment. Fuel economy was evaluated by introducing several devices to reduce outer air resistance. The test was conducted by changing the experimental method of SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure - Type II test. As a result, air resistance decreased by at least 15 % and fuel economy improved by at least 13 %. This study sought to reduce greenhouse gas and improve fuel economy by applying several devices to a test vehicle to lower air resistance.

• Clean Technology
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• v.13 no.1 s.36
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• pp.64-71
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• 2007

The selection of a suitable adsorbent for removing organic sulfur compounds tetrahydrothiophene (THT) and t-butylmercaptan (TBM) from natural gas has been carried out. The saturation adsorption capacity for the sulfur compounds were determined by pulse adsorption method for a group of nanoporous materials, including Na-Y, Na-ZSM-5, Na,K-ET(A)S-10, Na-Mordenite, Na,K-Clinoptitolite, Ti/MCM-41, Ti/SBA-15 and amorphous titanosilicates. Among the materials tested, Na-Y and Na,K-ET(A)S-10 zeolites showed high adsorptive capacities for THT and TBM. The saturation capacity for THT on Na,K-ETS-10 was comparable with that on Na-Y zeolite, which is well known as an effective adsorbent. The capacity and adsorptivity for THT and TBM on Na,K-ETAS-10 were improved by an increase in crystallinity of Na,K-ETAS-10. An investigation of the competitive adsorption between THT and TBM from the breakthrough test using a simulated natural gas indicates that Na,K-ETS-10 selectively adsorbs THT. The breakthrough capacity for THT on Na,K-ETS-10 was 1.19 mmol/g. The results show that the high adsorption performance of Na.K-ETS-10 and Na,K-ETAS-10 is due to the highly exchanged cations in the zeolitic structure which exhibit the strong electrostatic interactions with organic sulfur compounds and their wide pore nature.