• Journal of Life Science
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• v.29 no.11
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• pp.1258-1266
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• 2019

Yangkyuksanhwa-Tang (YKSH), consisting of nine different herbs, is commonly used in Soyangin-type individuals with stroke, based on the Sasang Constitution Theory in Korea. However, no evidence has yet confirmed a beneficial effect of YKSH in ischemic stroke treatment. In this study, we investigated the effects of YKSH on ischemic brain injury in a mouse model of cerebral ischemia. Focal cerebral ischemia in mice was induced by photothrombosis, and behavioral recovery was evaluated. Infarct volume, inflammation, and newly generated cells were evaluated by histology and immunochemistry. YKSH treatment resulted in a significant recovery from the motor impairments induced by focal cerebral ischemia, as determined with wire grip and rotarod tests. YKSH treatment also decreased the infarct volume and the number of cells positive for tumor necrosis factor-${\alpha}$ and myeloperoxidase when compared with a vehicle-treated control group. By contrast, YKSH treatment considerably increased the number of cells positive for glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1, as well as the number of cells doubly positive for Ki67/doublecortin when compared with the vehicle-treated group. These results suggest that YKSH treatment attenuated the infarct size by anti-inflammatory action, astrocyte and microglia activation, and neuronal proliferation, thereby facilitating neurofunctional recovery from a cerebral ischemic assault. YKSH could therefore be a potential treatment for neurofunctional restoration of the injured brains of patients with stroke.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.10
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• pp.738-746
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• 2019

Instead of hydraulic actuation systems, an electromechanical actuation system is more efficient in terms of weight, cost, and test evaluation in the thrust vector control of the 7-ton gimbal engine used in the Korea Space Launch Vehicle-II(KSLV-II) $3^{rd}$ stage. The electromechanical actuator is a kind of servo actuator with position feedback and uses a BLDC motor that can operate at high vacuum. In the case of the gimballed rocket engine, a synthetic resonance phenomenon may occur due to a combination of a vibration mode of the actuator itself, a bending mode of the launcher structure, and an inertial load of the gimbals engine. When the synthetic resonance occurs, the control of the rocket attitude becomes unstable. Therefore, the requirements for the stiffness have been applied in consideration of the gimbal engine characteristics, the support structure, and the actuating system. For the 7-ton gimbal engine of the KSLV-II $3^{rd}$ stage, the stiffness requirement of the actuation system is $3.94{\times}10^7N/m$, and the direct drive type electromechanical actuator is designed to satisfy this requirement. In this paper, an equivalent stiffness analysis model of a direct drive electromechanical actuator designed based on the stiffness requirements is proposed and verified by experimental results.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.1
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• pp.11-22
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• 2020

In this study, we investigated anti-pigmentation effect of a hexapeptide. The peptide significantly reduced melanin contents and inhibited tyrosinase activity in a dose-dependent manner, in which tyrosinase is a key enzyme in melanogenesis. The peptide also significantly reduced the expression levels of tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1) and their upstream transcription factor, microphthalmia-associated transcription factor (MITF). Furthermore, the peptide suppressed the phosphorylation level of cAMP-response element binding protein (CREB), a transcription factor of MITF, and increased the phosphorylation level of extracellular signal-regulated kinase (ERK), a kinase mediates MITF phosphorylation and proteasomal degradation. The peptide significantly inhibited the expression of Rab27A, Melanophilin, and MyosinVa, the components of motor complex involved in intracellular movement of melanosome. These results suggest that Hexapeptide could be used as an effective whitening agent that has inhibitory effect on melanin production and melanosome transport by regulating expression and degradation of MITF in melanocytes.

• Journal of Magnetics
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• v.20 no.1
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• pp.52-56
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• 2015

The purpose of the current study was to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) in conjunction with mirror therapy on the balance function of patients with sub-acute stroke hemiparesis. This study was conducted with 36 subjects who were diagnosed with a hemiparesis due to stroke. Participants in the experimental (19 members) and control groups (17 members) received rTMS and sham rTMS during 10 minute sessions each, which were carried out five days per week for four weeks. This was followed by the mirror therapy over 30 minute sessions, which were carried out five days per week for four weeks. Motor recovery was assessed by balance index, dynamic limits of stability, Berg balance scale, and time up go test. The change values of the balance index ($-2.06{\pm}1.99$ versus $-0.41{\pm}1.11$), dynamic limits of stability ($3.68{\pm}2.71$ versus $1.17{\pm}2.38$), and time up go test ($-7.05{\pm}5.64$ score versus $-3.35{\pm}5.30$ score) were significantly higher in the experimental group than in the control group (p < 0.05). At post-test, balance index ($4.08{\pm}1.14$ versus $5.09{\pm}1.04$), dynamic limits of stability ($13.75{\pm}0.60$ versus $11.73{\pm}3.53$), and time up go test ($23.89{\pm}4.51$ versus $28.82{\pm}3.07$) were significantly higher in the experimental group than in the control group (p < 0.05). In the experimental group, significant differences were found in the pre- and post-test scores for the balance index, dynamic limits of stability, Berg balance scale, and time up go test (p < 0.01). In the control group, a significant difference was observed between the pre- and post-test only for the Berg balance scale and time up go test (p < 0.05). These findings demonstrate that the application of 1Hz rTMS in conjunction with mirror therapy can be helpful in improving the balance function of patients with sub-acute stroke hemiparesis, and this may be used as a practical adjunct to routine rehabilitation therapy.

• Korean Journal of Psychosomatic Medicine
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• v.23 no.1
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• pp.66-69
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• 2015

In addition to classical triad such as gait disturbance, urinary incontinence and dementia, parkinsonian extrapyramidal motor signs and neuropsychiatric symptoms can be observed in patients with normal pressure hydrocephalus (NPH). In our case, a 46 year old female patient showed extrapyramidal symptoms such as bradykinesia, rigidity and neuropsychiatric symptoms such as agitation, anxiety, restlessness and regressed behavior beside two(gait disturbance & urinary incontinence) symptoms of three classical triad. It was difficult to diagnose this patient as NPH from the beginning because of her relatively young age and previous psychiatric mediation history for controlling advanced anxiety and affective disorder. Antiparkinsonian agents and discontinuation of psychiatric medications did not work for this patient. Patient's brain computed tomographic finding showed enlarged ventricles. We suspected NPH and did empirical drainage of 30mL CSF. Finally, patient's pyramidal and neuropsychiatric symptoms as well as two of three classical triad of NPH were improved dramatically within several days. It is important to consider NPH as one of the differential diagnosis in patient with parkinsonian symptoms and various neuropsychiatric symptoms who did not respond to usual clinical management especially in case of ventricular enlargement in neuroimaging because of its treatable property by CSF shunt operation.

• Journal of Aerospace System Engineering
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• v.15 no.5
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• pp.24-32
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• 2021

Personal Air Vehicle (PAV), Cargo UAS (Cargo UAS), and existing manned and unmanned aircraft are key vehicles for urban air mobility (UAM), and should demonstrate compatibility for the design of aircraft systems. The safety assessment required by for certification to ensure safety and reliability should be systematically performed throughout the entire cycle from the beginning of the aircraft development process. However, with the increasing complexity of safety critical aviation systems and the application of state-of-the-art systems, conventional experience-based and procedural-based safety evaluation methods make ir difficult to objectively assess safety requirements and system safety. Therefore, Model-Based Safety Assessment (MBSA) using modeling and simulation techniques is actively being studied at domestic and foreign countries to address these problems. In this paper, we propose a Model-Based Safety Evaluation framework utilizing modeling and simulation-based integrated flight simulators. Our case studies on the Traffic Collision Availability System (TCAS) and Wheel Brake System (WBS) confirmed that they are practical for future safety assessments.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.3
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• pp.58-72
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• 2021

In July 2021, UNCTAD classified Korea as a developed country. After the Korean War in the 1950s, economic development was promoted despite difficult conditions, resulting in epoch-making national growth. However, in order to respond to the rapidly changing global economy, it is necessary to continuously study the domestic industrial ecosystem and prepare strategies for continuous change and growth. This study analyzed the industrial ecosystem of the automobile industry where it is possible to obtain transaction data between companies by applying complexity spatial network analysis. For data, 295 corporate data(node data) and 607 transaction data (link data) were used. As a result of checking the spatial distribution by geocoding the address of the company, the automobile industry-related companies were concentrated in the Seoul metropolitan area and the Southeastern(Dongnam) region. The node importance was measured through degree centrality, betweenness centrality, closeness centrality, and eigenvector centrality, and the network structure was confirmed by identifying density, distance, community detection, and assortativity and disassortivity. As a result, among the automakers, Hyundai Motor, Kia Motors, and GM Korea were included in the top 15 in 4 indicators of node centrality. In terms of company location, companies located in the Seoul metropolitan area were included in the top 15. In terms of company size, most of the large companies with more than 1,000 employees were included in the top 15 for degree centrality and betweenness centrality. Regarding closeness centrality and eigenvector centrality, most of the companies with 500 or less employees were included in the top 15, except for automakers. In the structure of the network, the density was 0.01390522 and the average distance was 3.422481. As a result of community detection using the fast greedy algorithm, 11 communities were finally derived.

• Journal of IKEEE
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• v.25 no.3
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• pp.485-492
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• 2021

In this paper, we propose the development of a defect inspection system for polygonal containers. Embedded board consists of main part, communication part, input/output part, etc. The main unit is a main arithmetic unit, and the operating system that drives the embedded board is ported to control input/output for external communication, sensors and control. The input/output unit converts the electrical signals of the sensors installed in the field into digital and transmits them to the main module and plays the role of controlling the external stepper motor. The communication unit performs a role of setting an image capturing camera trigger and driving setting of the control device. The input/output unit converts the electrical signals of the control switches and sensors into digital and transmits them to the main module. In the input circuit for receiving the pulse input related to the operation mode, etc., a photocoupler is designed for each input port in order to minimize the interference of external noise. In order to objectively evaluate the accuracy of the development of the proposed polygonal container defect inspection system, comparison with other machine vision inspection systems is required, but it is impossible because there is currently no machine vision inspection system for polygonal containers. Therefore, by measuring the operation timing with an oscilloscope, it was confirmed that waveforms such as Test Time, One Angle Pulse Value, One Pulse Time, Camera Trigger Pulse, and BLU brightness control were accurately output.

• Journal of Korean Society of Spine Surgery
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• v.25 no.4
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• pp.180-184
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• 2018

Study Design: Case report Objectives: To document fistula formation between the disc and dura by an unrecognized dural tear after percutaneous endoscopic lumbar discectomy (PELD). Summary of Literature Review: The risk of durotomy is relatively low with PELD, but cases of unrecognized durotomies have been reported. An effective diagnostic tool for such situations has not yet been identified. Materials and Methods: A patient twice underwent transforaminal PELD under the diagnosis of a herniated lumbar disc at L4-5. She still complained of intractable pain and motor weakness around the left lower extremity at 6 months postoperatively. Magnetic resonance imaging showed no specific findings suggestive of violation of the nerve root. However, L5 and S1 nerve root injury was noted on electromyography. An exploratory operation was planned to characterize damage to the neural structures. Results: In the exploration, a dural tear was found at the previous operative site, along with a fistula between the disc and dura was also found at the dural tear site. The durotomy site was located on the ventrolateral side of the dura and measured approximately 5 mm. The durotomy site was repaired with Nylon 5-0 and adhesive sealants. The patient's preoperative symptoms diminished considerably. Conclusions: Fistula formation between the disc and dura can be caused by an unrecognized dural tear after PELD. Discography is a reliable diagnostic tool for fistulas formed by an unrecognized durotomy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.642-648
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• 2019

This paper presents a fast back-type transfer device for snack food processing that uses the inertia of transferred material. A conventional conveying system is a drive system that uses a belt conveyor and mechanical crank, which generate noise and vibration and cause environmental pollution. Vibration and noise are reduced in the proposed fast back feeding device by using a counterweight. The crank drive unit was replaced with a linear servomotor, and an equilibrium device was designed to balance the force due to acceleration. This makes it is possible to adjust the forward and backward speed and acceleration through PLC control. A vibration damper device offsets the vibration force of the periodic shock form. The main cause of the vibration was identified through vibration analysis, and reduction measures were established. We verified the effectiveness of the vibration by making a prototype and performing about 10 vibration tests. Because no mechanical transducer is needed, energy loss, noise, and vibration do not occur, and the operating speed is not limited.