• Transactions of the Korean hydrogen and new energy society
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• v.33 no.5
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• pp.470-498
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• 2022

Recently, the world has been considering hydrogen energy as the primary energy transition means to achieve carbon neutrality by 2050. In order to achieve the goal of reducing greenhouse gas emissions, Korea is also promoting a clean hydrogen economy. However, it is necessary to introduce various clean hydrogen from overseas so that the projected demand can not meet the domestically produced. For this study, we conducted the policy comparison approach between countries other than the generally considered technical and economic approaches. The finding proposes the direction of bilateral cooperation for a strategy of securing overseas clean hydrogen from a geopolitical perspective. Germany was a target country for the policy comparison since it has a high proportion of manufacturing, like Korea, and is taking the lead in the renewable-based energy transition policy. According to the survey and analysis of the policy establishment status and new projects of the two countries, Germany is promoting bilateral international cooperation in the hydrogen area with about 33 countries based on 7 types of activities. In comparison, Korea is involved in bilateral cooperation with about 12 countries on relatively few activities. Among the types of bilateral cooperation, R&D cooperation with advanced countries for hydrogen technology was a common activity type. Germany preemptively promotes cooperation for demonstration and commercialization, considering geopolitical means and strengthening manpower training and assistance on policy and regulation to preoccupy the market for the future. Therefore, it is necessary to consider establishing a network of an entire life cycle of supply and demand network that links the future market with securing clean hydrogen considering the geopolitical distribution. To this end, Korea also needs to expand bilateral cooperation countries by activity type, and it seems necessary to seek various geopolitical-based bilateral cooperation and support measures for developing countries to diversify the supply sources of hydrogen.

• Journal of Korean Neurosurgical Society
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• v.45 no.3
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• pp.164-168
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• 2009

Objective : Bilateral C1-2 transarticular screw fixation (TAF) with interspinous wiring has been the best treatment for atlantoaxial instability (AAI). However, several factors may disturb satisfactory placement of bilateral screws. This study evaluates the usefulness of unilateral TAF when bilateral TAF is not available. Methods : Between January 2003 and December 2007, TAF was performed in 54 patients with AAI. Preoperative studies including cervical x-ray, three dimensional computed tomogram, CT angiogram, and magnetic resonance image were checked. The atlanto-dental interval (ADI) was measured in preoperative period, immediate postoperatively, and postoperative 1, 3 and 6 months. Results : Unilateral TAF was performed in 27 patients (50%). The causes of unilateral TAF were anomalous course of vertebral artery in 20 patients (74%), severe degenerative arthritis in 3 (11%), fracture of C1 in 2, hemangioblastoma in one, and screw malposition in one. The mean ADI in unilateral group was measured as 2.63 mm in immediate postoperatively, 2.61 mm in 1 month, 2.64 mm in 3 months and 2.61 mm in 6 months postoperatively. The mean ADI of bilateral group was also measured as following; 2.76 mm in immediate postoperative, 2.71 mm in 1 month, 2.73 mm in 3 months, 2.73 mm in 6 months postoperatively. Comparison of ADI measurement showed no significant difference in both groups, and moreover fusion rate was 100% in bilateral and 96.3% in unilateral group (p=0.317). Conclusion : Even though bilateral TAF is best option for AAI in biomechanical perspectives, unilateral screw fixation also can be a useful alternative in otherwise dangerous or infeasible cases through bilateral screw placement.

• Archives of Plastic Surgery
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• v.46 no.2
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• pp.114-121
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• 2019

Background Bilateral cleft lip deformity is much more difficult to correct than unilateral cleft lip deformity. The complexity of the deformity and the sensitive relationships between the arrangement of the muscles and the characteristics of the external lip necessitate a comprehensive preoperative plan for management. The purpose of this study was to evaluate the repair of bilateral cleft lip using the Byrd modification of the traditional Millard and Manchester methods. A key component of this repair technique is focused on reconstruction of the central tubercle. Methods Fourteen patients with mean age of 5.7 months presented with bilateral cleft lip deformity and were operated on using a modification of the Millard and Manchester techniques. Patients with a very wide cleft lip and protruded or rotated premaxilla were excluded from this study. We analyzed 30 normal children for a comparison with our patients in terms of anthropometric measurements. Results By the end of the follow-up period (between 9 and 19 months), all our patients had obtained a full central segment with adequate white roll in the central segment and a deep gingivolabial sulcus, and we obtained nearly normal anthropometric measurements in comparison with age-matched normal children. Conclusions We recommend this modified technique for the treatment of bilateral cleft lip deformity.

• Korean Journal of Applied Biomechanics
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• v.23 no.2
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• pp.149-157
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• 2013

In the present study, we aimed to elucidate how muscle strength and activity are affected by movement pattern(bilateral [BLM] & unilateral movement [ULM]) and movement velocity($0^{\circ}$/s, $60^{\circ}$/s, $120^{\circ}$/s) at maximum effort, and to elucidate the relationship between a left/right asymmetry and bilateral deficit. A total of 18 healthy males participated in the study. Each participant performed maximum knee extension bilaterally and unilaterally while the EMG and moment were recorded, and then the relationships between the asymmetry and bilateral deficit were analyzed. The peak moments for the isokinetic motion at $60^{\circ}$/s and $120^{\circ}$/s and overall muscle activities of lower extremity were significantly reduced for the BLM in comparison to the ULM. And though the asymmetry in ULM were maintained during BLM at all velocities, the bilateral deficits at the velocity of $0^{\circ}\acute{y}$/s and $120^{\circ}\acute{y}$/s were significantly correlated with increased asymmetries of muscle strength in ULM. In conclusion, the reduction in the muscle strength exhibited in bilateral knee extension was shown to arise partially from a reduction in muscle activity, and left/right asymmetry was found to be associated with mechanical reduction in bilateral movement. These findings suggest that training aimed at increasing muscle strength must involve methods and strategies intended to reduce left/right asymmetry.

• The Journal of Korean Physical Therapy
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• v.34 no.2
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• pp.57-62
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• 2022

Purpose: The purpose of this study was to determine the effects of bilateral visual feedback training with visual targets on the postural balance and fall efficacy of stroke patients with hemiparesis. Methods: A total of 24 stroke patients with hemiparesis were randomly assigned to either a bilateral visual feedback training (BVFT, n=8) group, unilateral visual feedback training (UVFT, n=8) group, or a control group (n=8). The BVFT and UVFT groups performed weight-bearing training on the bilateral (less-affected and affected side) or unilateral side (affected side) with visual feedback using visual targets. The control group performed squat training without visual feedback using visual targets. The training program was conducted in the form of 3 sets a day, 3 times a week, for 4 weeks. The participants were evaluated using the Berg balance scale (BBS), lateral reaching test (LRT), timed up and go test (TUG), and the activities-specific balance confidence scale (ABC). Results: In the intra-group comparison after the intervention, the BVFT group showed a significant difference in the BBS, TUG, affected and less-affected side LRT, and ABC (p<0.05). The UVFT group showed a significant difference in the BBS and ABC (p<0.05). In the inter-group comparison after the intervention, the BVFT group showed significant improvements in their BBS, affected side LRT, and TUG, when compared to the control group (p<0.05). Conclusion: These findings show that bilateral visual feedback training with visual targets during bilateral weight-bearing exercises can improve the postural balance function in stroke patients.

• Journal of Korean Neurosurgical Society
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• v.42 no.4
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• pp.305-310
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• 2007

Objective : Combined antero-posterior fixation has been a standard method for bilateral interfacetal dislocation in cervical spine. The purpose of this study is to evaluate the efficacy and complication of anterior cervical stabilization in treatment of bilateral interfacetal dislocation. Methods : A total of 65 cases of traumatic bilateral interfacetal dislocation in cervical spine who were managed in our institution, from Mar. 1997 to Feb. 2006, were included in this study. Closed reduction was tried in all cases before operation. If closed reduction was accomplished successfully, only anterior cervical fixation was performed (Group I), and attempted to place screws bicortically as possible with unicortical screws. If failed, posterior open reduction with fixation was first tried, followed by anterior cervical fixation (Group II). All patients were evaluated for neurological outcome and radiological evidence of healing. Results : The Group I included 47 patients and the Group II, 18 patients. The improvement of Frankel grade and increase of mean cervical lordosis angles were not statistically different between two groups. Screw-plate system used did not influence the outcome. On follow up, solid bone fusion was evident and there were no cases of instability in both groups. Conclusion : Our study demonstrated that anterior cervical fixation on BID is safe and effective in comparison with combined antero-posterior cervical fixation.

• Journal of Korean Neurosurgical Society
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• v.57 no.6
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• pp.460-464
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• 2015

Objective : Bilateral C1 lateral mass and C2 pedicle screw fixation (C1LM-C2P) is an ideal technique for correcting atlantoaxial instability (AAI). However, the inevitable situation of vertebral artery injury or unfavorable bone structure may necessitate the use of unilateral C1LM-C2P. This study compares the fusion rates of the C1 lateral mass and C2 pedicle screw in the unilateral and bilateral methods. Methods : Over five years, C1LM-C2P was performed in 25 patients with AAI in our institute. Preoperative studies including cervical X-ray, three-dimensional computed tomography (CT), CT angiogram, and magnetic resonance imaging were performed. To evaluate bony fusion, measurements of the atlanto-dental interval (ADI) and CT scans were performed in the preoperative period, immediate postoperative period, and postoperatively at 1, 3, 6, and 12 months. Results : Unilateral C1LM-C2P was performed in 11 patients (44%). The need to perform unilateral C1LM-C2P was due to anomalous course of the vertebral artery in eight patients (73%) and severe degenerative arthritis in three patients (27%). The mean ADI in the bilateral group was 2.09 mm in the immediate postoperative period and 1.75 mm in 12-months postoperatively. The mean ADI in the unilateral group was 1.82 mm in the immediate postoperative period and 1.91 mm in 12-months postoperatively. Comparison of ADI measurements showed no significant differences in either group (p=0.893), and the fusion rate was 100% in both groups. Conclusion : Although bilateral C1LM-C2P is effective for AAI from a biomechanical perspective, unilateral screw fixation is a useful alternative in patients with anatomical variations.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1511-1516
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• 2020

The Korea Research Institute of Standards and Science (KRISS) established a new standard of the absorbed dose to water in LINAC X-ray beams. To confirm the equivalence of the new standard with other national metrology institutes (NMIs), a bilateral comparison study of the absorbed dose to water in high energy X-ray beams was performed between the KRISS and the National Metrology Institute of Japan (NMIJ). The comparison was made in-directly. Three transfer chambers were calibrated in the high energy X-ray beams by both laboratories and the calibration coefficients were compared. The average ratios of the calibration coefficients of the three transfer chambers obtained by the KRISS to those obtained by the NMIJ were 1.004, 1.006, 1.006, 1.007 for 6, 10, 15 and 18 MV X-ray beams, respectively. The calibration coefficients obtained at the KRISS were higher than those at the NMIJ but they were in good agreement within the expanded uncertainty of 1.0% (k = 2). The results of this study will be used as the evidence for the KRISS standard being comparable with those of other NMIs, temporarily, in the interim period up to finalizing a key comparison study, BIPM.RI(I)-K6 managed by the Consultative Committee for Ionizing Radiation.

• Journal of Korea Multimedia Society
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• v.16 no.6
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• pp.746-755
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• 2013

This paper presents a three dimensional bilateral filter detecting target trajectory, extracting spatial target information using two dimensional bilateral filter and temporal target information using one dimensional bilateral filter. In order to discriminate edge pixel with flat background and target region spatially and temporally, spatial and temporal variance are used for an image and temporal profile. With this procedure, background and background profile are predicted without original target through two dimensional and one dimensional bilateral filter. Finally, using spatially predicted background and temporally predicted background profile, small target can be detected. For comparison of existing target detection methods and the proposed method, the receiver operating characteristics (ROC) is used in experimental results. Experimental results show that the proposed method has superior target detection rate and lower false alarm rate.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.06a
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• pp.81-83
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• 2014

This paper provides the performance comparison of selected post filters for depth map in 3D video system. In the performance comparison, the dilation filter which is currently adopted in 3D-ATM reference S/W, the bilateral filter, and the depth-oriented depth boundary reconstruction filter. In the paper, we first introduce those filters in details, and show the experimental results as post filter in 3D video system.