• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.177-185
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• 2021

Clinical applications of translucent zirconia as well as traditional zirconia (3 mol% yttria stabilized tetragonal zirconia polycrystal, 3Y-TZP) are increasing. For this reason, studies on factors affecting the optical properties of dental zirconia have been continuously reported. The optical effect of dental zirconia may vary depending on the yttria content, the thickness of the prosthesis, the sintering process, polishing, glazing and cementation in laboratory and clinical procedures. Increasing the yttria concentration can reduce the masking effect. Translucency decreases as the thickness of the restoration increases, but the required thickness may vary depending on the properties of the zirconia block. The high-speed sintering method can shorten the manufacturing time, but in some cases, the translucency of the prosthesis may decrease. In addition, the optical properties can be affected by the surface roughness of zirconia and the polishing process. The use of an appropriate colored cement can help with the masking effect of zirconia and can be useful for color matching for more esthetic results.

• Journal of the Korean Orthopaedic Association
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• v.56 no.2
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• pp.103-116
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• 2021

The use of 3-dimensional (3D) printing is becoming more common, and its use is increasing in the orthopedic surgery. Currently, there are four major methods of using 3D printing technology in orthopedic surgery. First, surgical planning simulation using 3D printing model; second, patient-specific surgical instruments; third, production of customized prosthesis using 3D printing technique; fourth, patient-specific prosthesis produced by 3D printing. The areas of orthopedic surgery where 3D printing technology can be used are shoulder joint, spine, hip and pelvis, knee joints, ankle joint, and tumors. Since the diseases and characteristics handled by each area are different, the method of using 3D printing technology is also slightly different in each area. However, using 3D printing technology in all areas can increase the efficiency of surgery, shorten the surgery time, and reduce radiation exposure intraoperatively. 3D printing technology can be of great help in treating patients with particularly complex and difficult orthopedic diseases or fractures. Therefore, the orthopedic surgeon should make the most of the benefits of the 3D printing technology so that patient can be treated effectively.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.313-319
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• 2022

Complete dentures are one of the most basic treatment methods for the treatment of edentulous patients. The manufacturing process of traditional complete dentures goes through the steps of taking primary impressions, secondary impressions, jaw relation record, trying in wax denture, and final denture insertion. Multiple visits and complex manufacturing procedures are required, and errors may occur in each step. With the development of digital technology, manufacturing steps have been reduced by introducing digital technology to the denture treatment process. In the process of manufacturing dentures by introducing a digital process, a more precise work is possible using Computer-Aided Design, and it is possible to shorten the period of labor and reduce the number of visits. In this case, the anterior teeth arrangement of the patient's existing dentures was transferred to the final dentures using a digital method. After taking impression, try-in dentures were digitally fabricated and tried in the oral cavity to evaluate their retention in the oral cavity. Final dentures were manufactured by milling process. The number of visits was reduced, satisfactory retention and stability of dentures were obtained, and aesthetic recovery was achieved.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.33-38
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• 1995

This experiment was conducted to elucidate the effect of the midsummer drainage times on lodging characters, field lodging and yield in direct seeding rice culture in puddled soil. Dongjinbyeo was seeded at May 11 by seeding machine with 4cm of furrow depth and drained, one（50days after seeding DAS）） two （30DAS and 50DAS）, and three times （30DAS, and 50DAS and 60DAS）. The results are as follows. Culm length was shorten and the wall of N3, N4 were thicken as the drain-age times were increased. As the drainage times were increased breaking weights were increased but the lodging index were decreased. Lodging was occurred seriousely at none drainage, but wasn't occurred two or three times drainage. Yield was higher at 1~2 times drainage compared with none and three times drainage. Therefore, two times midsummer drainage is recommend-able water management method for direct seeding rice culture in puddled soil.

• Journal of Platform Technology
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• v.10 no.4
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• pp.25-38
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• 2022

Recently, it is reported that the Korean Unmanned Aerial Vehicle (UAV) interface protocol (K-4586) based on STANAG-4586 is being developed to secure interoperability between UAVs. The core elements of the K-4586-based Unmanned Aircraft System (UAS) are the Core UAV Control System (CUCS), Vehicle Specific Module (VSM), Data Link Interface (DLI), and C4I systems. In UAS based on K-4586, the DLI function for transmitting and receiving messages to link UAVs is included in VSM and CUCS respectively. The Generator/Analyzer (G/A) tool is an apparatus that is developed for protocol conformance verification for VSM and CUCS, and G/A tools with DLI message transmitting and receiving should be developed separately. Core applications (VSM, CUCS, DLI) and G/A tools based on K-4586 may be developed independently depending on the developers. If the DLI message modules are different for each developer, the scope and results of protocol conformance verification will be dissimilar, and some problems may happen during system integration. In this study, common DLI message module based on the API was designed to provide the DLI message transmitting and receiving function necessary to the development of core applications and the protocol conformance verification tool of based on K-4586. When applying the proposed common DLI message module, it can be expected to shorten the UAS system development period and reduce costs, and ensure conformance of protocol. In this paper, the design and implementation method for the common DLI message module based on API was proposed and the results of functional test was described.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.729-736
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• 2023

Purpose: The purpose of the Activation of Public Transportation by Analysis of Factors Influencing Satisfaction of Commuting Hours in the Metropolitan Area. Method: This study analyzed the factors affecting wide-area commuting time and satisfaction for office workers who perform wide-area commuting. Result: in the case of commuting satisfaction for wide-area commuting hours by region, commuting time satisfaction was relatively low in the metropolitan area as the average commuting time was high, and commuting time satisfaction was relatively high in the non-metropolitan area as the average commuting time was low. Conclusion: In the future, the government will establish or improve express railways and wide-area buses to reduce wide-area commuting time, and build urban highways to shorten passenger car use time, which will reduce commuting time, but qualitative indicators are more important. In other words, even if commuting time is long, life satisfaction increases, so quality of life is important, and it is necessary to improve commuting time satisfaction rather than simple indicators of commuting time, so both qualitative and quantitative aspects of commuting time need to be improved.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.5
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• pp.629-636
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• 1995

This study was carried out to clarify the proper nitrogen application methods under the different seedling density in puddled-soil drill seeding of rice. Seedling density was adjusted as 30, 60, 90, 120 and 150ea/$m^2$ just after emergence and nitrogen was applied with five methods including conventional respectively. The maximum tillering stage was shorten as the seedling density was increase but decreased the percentage of productive tillers. Lodging was occurred serverely as the seedling was more than 120ea/$m^2$, when nitrogen was applied at panicle initiation stage. Grain yield wasn't significantly different among seedling densities when it was more than 60ea/$m^2$, but the density of 30ea/$m^2$ was decreased. It wasn't significantly different among the nitrogen application methods when it was more than 90ea/m, but was higher at early application of tillering fertilizer (T$_2$) than conventional method when the seedling density was less than 60ea/$m^2$. Supposing that the yield of reseeding is the same as optimum seedling density, minimum seedling density needs for reseeding would be less than 55 ea/$m^2$ as the aspect of income allowed for managing expense.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.533-540
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• 1995

Attenuation correction is important in producing quantitative positron emission tomography (PET) images. Conventionally, photon attenuation effects are corrected using transmission measurements performed before tracer administration. The pre-injection transmission measurement approach may require a time delay between transmission and emission scans for the tracer studies requiring a long uptake period, about 45 minutes for F-18 deoxyglucose study. The time delay will limit patient throughput and increase the likelihood of patient motion. A technique lot performing simultaneous transmission and emission scans (T+E method) after the tracer injection has been validated. The T+E method substracts the emission counts contaminating the transmission measurements to produce accurate attenuation correction coefficients. This method has been evaluated in experiments using a cylindrical phantom filled with background water (5750 cc) containing $0.4{\mu}Ci/cc$ of F-18 fluoride ion and one insert cylinder (276 cc) containing $4.3{\mu}Ci/cc$. GE $Advance^{TM}$ PET scanner and Ge-68 rotating pin sources for transmission scanning were used for this investigation. Post-injection transmission scan and emission scan were peformed alternatively over time. The error in emission images corrected using post-infection transmission scan to emission images corrected transmission scan was 2.6% at the concentration of $1.0{\mu}Ci/cc$. No obvious differences in image quality and noise were apparent between the two images. The attenuation correction can be accomplished with post-injection transmission measurement using rotating pin sources and this method can significantly shorten the time between transmission and omission scans and thereby reduce the likelihood of patient motion and increase scanning throughput in PET.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.2 no.1
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• pp.65-73
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• 1999

Purpose: Regurgitation, vomiting and feeding intolerance are frequent in the neonates. Esophageal function and gastric peristalsis are not fully developed in the neonates, so we should give attention to reduce the incidence of regurgitation and vomiting after feeding. It is necessary to shorten the gastric emptying by change of feeding types and postprandial postures. Gastric emptying time was measured by ultrasound in the neonates to evaluate the effect of feeding types and postprandial postures. Method: We measured gastric antral cross sectional area along the abdominal aorta at the level of the superior mesenteric artery in longitudinal section at NPO state (4 hours after feeding), 0 and every 30 min. after feeding until the value goes below or back to the NPO state. Fifteen neonates were examined in each breast-fed and formula-fed group in supine position. Eighteen and 15 neonates were examined in supine and prone posture after formula feeding, respectively. We used 5 MHz convex prove with Aloka Echo Camera SSD-650. Result: 1) Gastric emptying time of breast-fed infants was $76.0{\pm}20.02$ min. which was significantly shorter than $96.0{\pm}20.28$ min. of formula-fed infants. 2) Gastric emptying time on postprandial prone posture was $85.0{\pm}22.43$ min. which was not significantly different from $96.0{\pm}20.28$ min. on postprandial supine posture. Conclusion: Breast feeding is strongly recommended to the neonates to shorten gastric emptying time. So we can expect to reduce the incidence of regurgitation, vomiting and feeding intolerance. The postprandial posture depends on the traditional trend which is safe and comfortable to the mothers.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.16 no.2
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• pp.86-92
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• 2016

Purpose: The $BH_4$ loading test is an important test that distinguishes PKU from $BH_4$ deficiency and identifies the $BH_4$ reactivity of PKU patients. Phenylalanine and $BH_4$ loading tests are useful methods that can shorten the length of hospital stay while improving patients' convenience. However, sufficient research on the dose of phenylalanine loading and $BH_4$ administration time after the loading has not been carried out. The present study investigates the effectiveness of the existing phenylalanine loading method by analyzing the medical records of six patients who underwent the $BH_4$ loading test after taking 100 mg/kg of phenylalanine patients. Methods: The medical records of six patients who underwent the $BH_4$ load test after taking 100 mg/kg of phenylalanine were examined out of 207 patients who were followed up in the Genetic Metabolic Clinic in Soonchunhyang University Hospital. All of the six patients had a low phenylalanine diet. First, they were taking 100 mg/kg of phenylalanine. 3 hours later, 20 mg/kg of $BH_4$ were loaded. The phenylalanine levels in the blood were continuously measured at 1, 2, 4, 6, 8, 12, and 24 hours by setting the time the $BH_4$ was loaded as the basal. Results: The average of the highest phenylalanine concentrations of six patients was $20.0{\pm}11.70mg/dL$. One reached the highest concentration seven hours after taking phenylalanine; another reached it five hours after that, and the remaining three reached it four hours after that. Only one patient reached the highest concentration within three hours. The phenylalanine levels of four out of six patients (66%) rose above $400{\mu}mol/L$ after being loaded with phenylalanine. The phenylalanine levels of the remaining two were 6.1 mg/dL ($366{\mu}mol/L$) and 5 mg/dL ($300{\mu}mol/L$), respectively. Conclusion: One of six patients (16%) reached the highest concentration three hours after taking 100 mg/kg of phenylalanine and four patients (66%) reached $400{\mu}mol/L$ or higher phenylalanine levels. There were patients whose phenylalanine levels did not rise above $400{\mu}mol/L$ using a commonly known test method; moreover, this method had the disadvantage of reaching the highest concentration after more than three hours. Therefore, it is considered that taking 200 mg/kg or more of phenylalanine and performing $BH_4$ loading four to six hours after taking phenylalanine are helpful in proper diagnosis.