• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.1
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• pp.1-5
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• 2006

The effect of A/B moi ratios and sintering temperatures on dielectric properties and microstructure of $(Ba_{0.93}Ca_{0.07})_m(Ti_{0.82}Zr_{0.18})O_3$ ceramics were investigated. The dielectric constant decreased with increasing the A/B mol ratio. However, the dielectric loss is improved. As the dielectric properties of A/B mol ratio with m = 1.009 at sintered temperature $1260^{\circ}C$, we obtained dielectric constant 12,800, dielectric loss $3.5\%$ and Y5V temperature characteristics. Highly reliable Ni-MLCCs, 1.6mm$(length){\time}0.8mm(width){\time}0.8mm$(height) with capacitance of 1.23 ${\mu}F$ and 야ssipation loss of $5.2\%$ were obtained employing dielectric material composed of $(Ba_{0.93}Ca_{0.07})_{1.009}(Ti_{0.82}Zr_{0.18})O_3$ - $MnO_2\;0.2wt\%-Y_2O_3\;0.18wt\%,\;-\;SO_2\;0.15wt\%-(Ba_{0.4}Ca_{0.6})SiO_3\;1wt\%$.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.6
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• pp.737-748
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• 1998

This study was carried out on 132 obese women who satisfied both of conditions for obesity: equal to or over 1.6 in Rohrer index and 90 in bust girth. The purpose of the study was to set up a sizing system using the loss function which would be a guide for obese women to select ready-to-wear of suitable size. The results were as follows. 1) In the sizing system for large size apparel industry, each company has 4 to 7 sizes that differ in their content and number. Producing only 5 sizes was trying to minimize the producti on expenses. 2) The sizing system according to the loss function was the follwings. The height was 3: 149, 154.5 and 161 cm. The bust girth was 5:96.5, 100.5, 104, 107.5, 112 cm. The hip girth was 5: 95, 99, 102.5, 105.5, 110 cm. 3) In comparing the cover ratio of the newly suggested sizing system for obese women's garment with that of the Korea Sizing system for women's garment, the former was founded to have the greater cover ratio.

• Nuclear Engineering and Technology
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• v.45 no.3
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• pp.347-360
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• 2013

This paper presents an experimental investigation of the small-break loss-of-coolant accident (SBLOCA) and the loss-of-feedwater accident (LOFW) in a scaled integral test facility of REX-10. REX-10 is a small integral-type PWR in which the coolant flow is driven by natural circulation, and the RCS is pressurized by the steam-gas pressurizer. The postulated accidents of REX-10 include the system depressurization initiated by the break of a nitrogen injection line connected to the steam-gas pressurizer and the complete loss of normal feedwater flow by the malfunction of control systems. The integral effect tests on SBLOCA and LOFW are conducted at the REX-10 Test Facility (RTF), a full-height full-pressure facility with reduced power by 1/50. The SBLOCA experiment is initiated by opening a flow passage out of the pressurizer vessel, and the LOFW experiment begins with the termination of the feedwater supply into the helical-coil steam generator. The experimental results reveal that the RTF can assure sufficient cooldown capability with the simulated PRHRS flow during these DBAs. In particular, the RTF exhibits faster pressurization during the LOFW test when employing the steam-gas pressurizer than the steam pressurizer. This experimental study can provide unique data to validate the thermal-hydraulic analysis code for REX-10.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.525-529
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• 2009

In this paper, microstrip patch antenna with diagonal slotted type using RFID is designed. This microstrip patch antenna is designed by considering the properties of critical parameter like the size, the truncating dimension, position of feed power and the height of airspace. the designed microstrip patch antenna has the lowest return loss in 915MHz, and in case of the voltage standing wave ratio(VSWR) is less than 1.2 under return loss -16dB, it has bandwidth of about 26MHz. Also, the microstrip patch antenna has the gain of 6dBi on the center frequency of 915MHz band and 2.8dB in the rate of reduction.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.51-57
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• 2012

The anterior maxillary incisor is the most traumatized region in the mouth and trauma is frequent between the ages of 8-10. Traumatic loss of teeth, can lead to many complications in children. Thus, as possible to keep traumatic teeth, but if you need extractions There may be. Complications occur and early tooth loss is frequent. Complications of early loss of central incisors are esthetic compromise, loss of vertical and horizontal width, height, contour of alveolar bone, tilting of adjacent teeth, arch length loss. Alveolar bone loss may affect normal function and stability, and results in esthetic problem for future prosthesis restoration. The 9-year-old girl and 6-year-old boy got early loss of upper central incisor. The amount of alveolar bone resorption was measured using cone beam computed tomograph and cast analysis.

• Journal of Korea Water Resources Association
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• v.41 no.3
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• pp.305-314
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• 2008

Urban sewer systems are designed to operate in open-channel flow regime and energy loss at circular manholes are usually not significant. However, the energy loss at manholes, often exceeding the friction loss of pipes under surcharge flow, is considered as one of the major causes of inundation in urban area. Therefore, it is necessary to analyze the head loss associated with manholes, especially in surcharge flow. Hydraulic experimental apparatus which can be changed the invert type(CASE A, B, C) and step height(CASE I, II, III) was installed for this study. The range of the experimental discharges were from $1.0{\ell}/sec$ to $5.6\;{\ell}/sec$. As the manhole diameter ratio($D_m/D_{in}$) increases, head loss coefficient increases due to strong horizontal swirl motion. Head loss coefficient was maximum because of strong oscillation of water surface when the range of manhole depth ratios($h_m/D_{in}$) were from 1.0 to 1.5. The average head loss coefficients for CASE A, B, and C were 0.45, 0.37, and 0.30, respectively. Accordingly, U-invert is most effective for energy loss reduction at circular manhole. This head loss coefficients could be available to design the urban sewer system with surcharge flow.

• The korean journal of orthodontics
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• v.43 no.2
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• pp.83-95
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• 2013

Objective: To evaluate the changes in cortical bone thickness, alveolar bone height, and the incidence of dehiscence and fenestration in the surrounding alveolar bone of posterior teeth after rapid maxillary expansion (RME) treatment using cone-beam computed tomography (CBCT). Methods: The CBCT records of 20 subjects (9 boys, mean age: $13.97{\pm}1.17$ years; 11 girls, mean age: $13.53{\pm}2.12$ year) that underwent RME were selected from the archives. CBCT scans had been taken before (T1) and after (T2) the RME. Moreover, 10 of the subjects had 6-month retention (T3) records. We used the CBCT data to evaluate the buccal and palatal aspects of the canines, first and second premolars, and the first molars at 3 vertical levels. The cortical bone thickness and alveolar bone height at T1 and T2 were evaluated with the paired-samples t-test or the Wilcoxon signed-rank test. Repeated measure ANOVA or the Friedman test was used to evaluate the statistical significance at T1, T2, and T3. Statistical significance was set at p < 0.05. Results: The buccal cortical bone thickness decreased gradually from baseline to the end of the retention period. After expansion, the buccal alveolar bone height was reduced significantly; however, this change was not statistically significant after the 6-month retention period. During the course of the treatment, the incidence of dehiscence and fenestration increased and decreased, respectively. Conclusions: RME may have detrimental effects on the supporting alveolar bone, since the thickness and height of the buccal alveolar bone decreased during the retention period.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.6
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• pp.259-265
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• 2014

Purpose: The purpose of this study is to evaluate the influence of intracapsular fracture lines of the mandibular condyle on the anatomical and functional recovery after non-surgical closed treatment. Methods: Clinical and radiological follow-up of 124 patients with intracapsular fractures of the mandibular condyle was performed after closed treatment between 2005 and 2012. The intracapsular fractures were classified into three categories: type A (medial condylar pole fracture), type B (lateral condylar pole fracture with loss of vertical height) and type M (multiple fragments or comminuted fracture). Results: By radiological finding, fracture types B and M lost up to 24% vertical height of the mandibular condyle compared to the height on the opposite side. In Type M, moderate to severe dysfunction was observed in 33% of the cases. Bilateral fractures were significantly associated with the risk of temporomandibular joint (TMJ) dysfunction in fracture types A and B. Bilateral fracture and TMJ dysfunction were not statistically significantly associated in type M fractures. Conclusion: Most of the mandibular intracapsular condylar fractures recovered acceptably after conservative non-surgical treatment with functional rehabilitation, even with some anatomical shortening of the condylar height. The poor functional recovery encountered in type M fractures, especially in cases with additional fracture sites and bilateral fractures, points up the limitation of closed treatment in such cases.

• Journal of Korean Neurosurgical Society
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• v.38 no.4
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• pp.255-258
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• 2005

Objective : Lumbar lordotic curve on L4 to S1 level is important in maintaining spinal sagittal alignment. Although there has been no definite report in lordotic value, loss of lumbar lordotic curve may lead to pathologic change especially in degenerative lumbar disease. This study examines the changes of lumbar lordotic curve after posterior lumbar interbody fusion with wedge shape cage. Methods : We studied 45patients who had undergone posterior lumbar interbody fusion with wedge shape cage and screw fixation due to degenerative lumbar disease. Preoperative and postoperative lateral radiographs were taken and one independent observer measured the change of lordotic curve and height of intervertebral space where cages were placed. Segmental lordotic curve angle was measured by Cobb method. Height of intervertebral space was measured by averaging the sum of anterior, posterior, and midpoint interbody distance. Clinical outcome was assessed on Prolo scale at 1month of postoperative period. Results : Nineteen paired wedge shape cages were placed on L4-5 level and 6 paired same cages were inserted on L5-S1 level. Among them, 18patients showed increased segmental lordotic curve angle. Mean increased segmental lordotic curve angle after placing the wedge shape cages was $1.96^{\circ}$. Mean increased disc height was 3.21mm. No cases showed retropulsion of cage. The clinical success rate on Prolo's scale was 92.0%. Conclusion : Posterior lumbar interbody fusion with wedge shape cage provides increased lordotic curve, increased height of intervertebral space, and satisfactory clinical outcome in a short-term period.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.4
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• pp.27-32
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• 2003

The Performance of micro combustor in various condition was exploited experimentally. Various geometric conditions of combustor were considered to figure out the performance of micro combustor. The micro combustor studied in this study was constant volume with cylindrical shape. Geometric parameters of combustor were defined to be combustor height and diameter. The effect of height was exploited parametrically with the size of 1mm, 2mm and 3mm. The effect of diameter was observed parameterized with 7.5mm and 15mm. Three different combustibles or Stoichiometric mixture of methane/air, hydrogen/air were used. Pressure transition during combustion process was recorded. The maximum pressure by combustion responded favorably with the change of height of combustor and the initial pressure. The flame propagation was visulized using Schlieren method. The flame propagation within combustor was observed when specific conditions such as combustor height and initial pressure over critical value was satisfied.