• 한국가시화정보학회:학술대회논문집
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• 2003.11a
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• pp.79-80
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• 2003

This paper presents experimental results on stirring characteristics in a microchannel with structures changed. We fabricated a new chaotic micro mixer and made by a RP(Rapid Rrototyping) technology. Flow visualization for the stirring effect was performed by using pure orator in a reservoir and fluorescent dye in the other. Chaotic mixing was achieved by introducing periodic perturbation in the field of the microchannel flow by means of shaped structures. It was found that the stirring is enormously enhanced at larger bock-height.

• Journal of Multimedia Information System
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• v.6 no.3
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• pp.119-124
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• 2019

In this paper, a method of detecting vehicle plates through depth pictures is proposed. A vehicle plate can be recognized by detecting the plane areas. First, plane factors of each square block are calculated. After that, the same plane areas are grouped by comparing the neighboring blocks to whether they are similar planes. Width and height for the detected plane area are obtained. If the height and width are matched to an actual vehicle plate, the area is recognized as a vehicle plate. Simulations results show that the recognition rates for the proposed method are about 87.8%.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.4
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• pp.63-71
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• 2010

This study was performed to evaluate the planting properties and root potential of planting block with mixing seeding of herbaceous plants and cool-season grasses in CSG blocks manufactured by cemented sand and materials (CSG) in order to develop environmentally friendly CSG block applied revegetation. Five types of CSG mix designs with cement contents were determined, and the mechanical properties of CSG materials were studied experimentally. To analyze growth properties of plants within CSG block, germination ratio, visual cover, plant height and root potential were measured in four weeks and eight weeks after seeding. The germination regardless mixture seeding of plants and CSG mixproportions started within 4 ~ 7 days after seeding and the germination ratio were in the range of 60 ~ 65 %. The visual cover of kinds of plants evaluated by visual rating system were in the range of 6 ~ 8 in case of seeding the species of cool-season grasses and were in the range of 4 ~ 6 in case of seeding the species of herbaceous plants in four weeks after seeding. The root potential of CSG block with the species of cool-season grasses and herbaceous plants were in the range of $5.7{\times}10^{-3}{\sim}7.7{\times}10^{-3}$ MPa and $2.3{\times}10^{-3}{\sim}6.7{\times}10^{-3}$ MPa in eight weeks after seeding, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.1
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• pp.69-79
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• 1990

This study intends to define the concept of human scale and visual preference which is frequently being used by environmental designers, and to explore the dimension of buildings and courtyards which is perceived as "human scale" and "visually preferable" by users (college students). As the subjects of this experiment were college students, "human scale" and "visual preferenoe" that were professional terms must be changed to understandable and compatible concept. The compatible concept for human scale was defined as the degree of friendliness and comfort, and that for visual preference was declined as the degree of like or dislike. The subjects thought that buildings with the height of 2.73 ∼5. 83 storides, the length of 27.44∼44.00m and the height ratio of 1.81 ∼5.41 were in human scale, and that buildings with height 2.60 ∼ 6.00 stories, the length of 25.7∼55.00 and the height ratio of 1.32∼6.41 were visually preferred. The block game used in this study was Proved to he a reliable and valid experimental method.

• Clinics in Orthopedic Surgery
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• v.10 no.4
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• pp.407-412
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• 2018

Background: We conducted this study to determine the optimal length of patellar and tibial bone blocks for the modified transtibial (TT) technique in anterior cruciate ligament (ACL) reconstruction using the bone-patellar tendon-bone (BPTB) graft. Methods: The current single-center, retrospective study was conducted in a total of 64 patients with an ACL tear who underwent surgery at our medical institution between March 2015 and February 2016. After harvesting the BPTB graft, we measured its length and that of the patellar tendon, patellar bone block, and tibial bone block using the arthroscopic ruler and double-checked measurements using a length gauge. Outcome measures included the length of tibial and femoral tunnels, inter-tunnel distance, length of the BPTB graft, patellar tendon, patellar bone block, and tibial bone block and graft-tunnel length mismatch. The total length of tunnels was defined as the sum of the length of the tibial tunnel, inter-tunnel distance and length of the femoral tunnel. Furthermore, the optimal length of the bone block was calculated as (the total length of tunnels - the length of the patellar tendon) / 2. We analyzed correlations of outcome measures with the height and body mass index of the patients. Results: There were 44 males (68.7%) and 20 females (31.3%) with a mean age of 31.8 years (range, 17 to 65 years). ACL reconstruction was performed on the left knee in 34 patients (53%) and on the right knee in 30 patients (47%). The optimal length of bone block was 21.7 mm (range, 19.5 to 23.5 mm). When the length of femoral tunnel was assumed as 25 mm and 30 mm, the optimal length of bone block was calculated as 19.6 mm (range, 17 to 21.5 mm) and 22.1 mm (range, 19.5 to 24 mm), respectively. On linear regression analysis, patients' height had a significant correlation with the length of tibial tunnel (p = 0.003), inter-tunnel distance (p = 0.014), and length of patellar tendon (p < 0.001). Conclusions: Our results indicate that it would be mandatory to determine the optimal length of tibial tunnel in the modified TT technique for ACL reconstruction using the BPTB graft. Further large-scale, multi-center studies are warranted to establish our results.

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.5
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• pp.273-280
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• 2023

Background: Intraoral local anesthesia is essential for delivering dental care; however, injection of this local anesthetic is perceived as the most painful and distressing agent for children, parents, and healthcare providers. Reducing pain as much as possible is essential to ensure smooth subsequent treatment procedures, especially in pediatric dentistry. In clinical practice, oral sucrose administration has been reported to decrease the pain during heel lance and cold pressor tests in neonates and children. This study aimed to determine whether the prior administration of a 30% sucrose solution reduced the pain related to inferior alveolar nerve block in children. Methods: A total of 42 healthy children aged 7-10 years requiring dental treatment of mandibular molars involving inferior alveolar nerve block were recruited. The participants' demographic details were recorded, height and weight were measured, and the anesthetic injection was delivered after receiving the respective intraoral sucrose solution and distilled water by the intervention (group 1) and control (group 2) group participants for 2 min. The subjective pain perceived during injection was measured using an animated emoji scale. The pain scores between the groups were compared using the Mann-Whitney U test. Results: The median pain score and range for the intervention and control groups were 4 (2 - 6) and 6 (4 - 8), respectively, and statistically significant differences (P < 0.001) were observed in the intervention group. Age, sex, height, and weight did not influence the analgesic effect of the sucrose solution. Conclusion: Oral administration of sucrose may relieve pain associated with inferior alveolar nerve block in children.

• Geomechanics and Engineering
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• v.13 no.6
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• pp.997-1010
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• 2017

The black box model is a relatively new option for nonlinear dynamic system identification. It can be used for prediction problems just based on analyzing the input and output data without considering the changes of the internal structure. In this paper, a black box model was presented to solve unconstrained overlying strata movement problems in coal mine production. Based on the black box theory, the overlying strata regional system was viewed as a "black box", and the black box model on overburden strata movement was established. Then, the rock mechanical properties and the mining thickness and mined-out section area were selected as the subject and object respectively, and the influences of coal mining on the overburden regional system were discussed. Finally, a corrected method for height prediction of the fractured zone was obtained. According to actual mine geological conditions, the measured geological data were introduced into the black box model of overlying strata movement for height calculation, and the fractured zone height was determined as 40.36 m, which was comparable to the actual height value (43.91 m) of the fractured zone detected by Double-block Leak Hunting in Drill. By comparing the calculation result and actual surface subsidence value, it can be concluded that the proposed model is adaptable for height prediction of the fractured zone.

• The Korean Journal of Pain
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• v.8 no.1
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• pp.159-163
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• 1995

Accidental high epidural block is a rare but serious complication. It can result from many factors, which include the volume and concentration of drug, posture, puncture site, age, pregnancy or intra-abdominal mass, and patients' height and weight. We had a case of accidental high epidural block recently. This is a case report which was confirmed by an epiduragram. A healthy 50-year-old woman with a huge uterine myoma was scheduled for a total abdominal hysterectomy under continous epidural analgesia. Epidural catheterization was carried out smoothly. However, an unexpected hypotension was noticed after an epidural injection of 2% lidocaine 25 ml. Thereafter, the patient was intubated and her respiration was controlled during the operation. Using the 5mg of ephedrine, her blood pressure and pulse were well maintained. The scheduled operation was carried out for one hour uneventfully, but after the operation, she felt paresthesia on her hands in the recovery room. To differentiate between the high epidural and the subdural blocks. We injected 5 ml of a water soluble Niopam 300 through the catheter postoperatively. It was observed on the epiduragram that the catheter was placed in the epidural space. It was suggested that the high epidural block was induced from the widespread diffusion through the narrowed epidural space due to the engorgement of the epidural venous plexus by the patient's huge uterine myoma.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.639-647
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• 2019

Recently, as the semiconductor integration technology due to miniaturization and high density of electronic equipment have developed, it is importantly recognized the application of thermal control system in order to release inner heat generated from chips, modules, In this study, we considered the heat transfer and pressure drop characteristics in a horizontal channel with four blocks using k-${\omega}$ SST turbulence model During CFD (Computational Fluid Dynamics) analysis, the parameters applied block width, block height, heat source and turbulence generator placement etc. As the boundary conditions of analysis, the channel inlet temperature and flow velocity were respectively 300 K and 3.84 m/s, the heat flux was $358W/m^2$. As a result, the heat transfer performance was decreased as the block width ratio (w/h) was increased, while it was increased as the block height ratio (h/w) was increased. In addition, as the arrangement of heat source size was increased to high heat flux from low heat flux, it was influenced by heat source size and the heat transfer coefficient showed a tendency to increase, When the turbulence generator was installed in the upper part of block No. 1 position the closely to the channel entrance, the heat transfer characteristics was greatly influenced on the whole of four heating blocks. and in oder to consider the pressure drop characteristics, we are able to select the most appropriate turbulence generator's position.

• Journal of the Korean Wood Science and Technology
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• v.17 no.2
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• pp.34-64
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• 1989

Corner block with anchor bolt(CBA) joint method used in knock-down type table furniture manufacturing can reduce the packing and transporting cost. Unfortunately. it also has the disastrous defect to be loosend and unstable during the service life mainly due to fatigue and creep(repeated and prolonged loading). So 22 joint groups constructed were tested to evaluate the effect of some design factors related to the size of side rail(apron). block attachment to side rail. and the number of anchor bolt as well as the effect of the type of corner block(mitered type vs. rectangular type) Usable strength from the stiffness coefficients of each joint group were analysed with SPSS /PC+ and described as the criteria of CBA joint construction. The conclusions were as follows: The height of side rail(50, 75 and 100 mm) and the addition of polyvinyl acetate(PVAc) emulsion in the corner block attactment to side rail had the effect on raising the usable strength of CBA joint with remarkable high significance. And the effect of 2 - anchor bolts was also superior to that of 1 - bolt significantly. However. the thickness of side rail(22 mm vs. 25 mm) had no effect on the strengthening the table joint rigidity. Mitered type corner block joint appeared to he recommendable for CBA jointed table construction rather than the rectangular type one regardless of the method of block attachment to side rail. The best result identified from Duncan's multiple comparison was in the construction with 25 mm thick and 100 mm height of side rail fastened using 2 - anchor bolts in mitered type corner block. But it would be reasonable to use 22 mm thick & 75 mm high side rail and mitered corner block with PVAc emulsion & 2 bolts considering the productivity and production cost down in the MDF furniture manufacturing industries.