• Fire Science and Engineering
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• v.23 no.3
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• pp.40-47
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• 2009

Nowadays the diversity and large-capacity of electric appliances are strong effect on electrical fires augment in an alarming way. But, as the inactive response characteristics of the existing RCD (Residual Current protective Device) used on low voltage power distribution system, so control of overload and electric short circuit faults, major causes of electrical fires, are not enough. Therefore, this paper is confirmed the unreliability of the existing RCD by electrical fault simulator and is proposed a Electrical Fire Disaster Prevention Device (EFDPD) by using a high precision current sensor (namely, reed switch) for the prevention of electrical disasters in low voltage power distribution system caused by overload or electric short circuit faults. The sensitive reed switch in the proposed EFDPD exactly detects the increased magnetic flux with the overload or the short current caused by a number of electrical faults, and the following, the EFDPD has double protection function which operates self circuit breaker or rapidly cuts off the existing RCD. The proposed EFDPD is confirmed the excellent characteristics in response velocity and accuracy in comparison with the conventional circuit breaker through various operation performance analysis. The proposed EFDPD can also prevent electrical disaster, like as electrical fires, which resulted from the malfunction and inactive response characteristics of the existing RCD.

• Journal of Korean Neurosurgical Society
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• v.60 no.5
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• pp.577-583
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• 2017

Objective : Laminoplasty is an effective surgical method for treating cervical degenerative disease. However, postoperative complications such as kyphosis, restriction of neck motion, and instability are often reported. Despite sufficient preoperative lordosis, this procedure often aggravates the lordotic curve of the cervical spine and straightens cervical alignment. Hence, it is important to examine preoperative risk factors associated with postoperative kyphotic alignment changes. Our study aimed to investigate preoperative radiologic parameters associated with kyphotic deformity post laminoplasty. Methods : We retrospectively reviewed the medical records of 49 patients who underwent open door laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL) at Pusan National University Yangsan Hospital between January 2011 and December 2015. Inclusion criteria were as follows : 1) preoperative diagnosis of OPLL or CSM, 2) no previous history of cervical spinal surgery, cervical trauma, tumor, or infection, 3) minimum of one-year follow-up post laminoplasty with proper radiologic examinations performed in outpatient clinics, and 4) cases showing C7 and T1 vertebral body in the preoperative cervical sagittal plane. The radiologic parameters examined included C2-C7 Cobb angles, T1 slope, C2-C7 sagittal vertical axis (SVA), range of motion (ROM) from C2-C7, segmental instability, and T2 signal change observed on magnetic resonance imaging (MRI). Clinical factors examined included preoperative modified Japanese Orthopedic Association scores, disease classification, duration of symptoms, and the range of operation levels. Results : Mean preoperative sagittal alignment was $13.01^{\circ}$ lordotic; $6.94^{\circ}$ lordotic postoperatively. Percentage of postoperative kyphosis was 80%. Patients were subdivided into two groups according to postoperative Cobb angle change; a control group (n=22) and kyphotic group (n=27). The kyphotic group consisted of patients with more than $5^{\circ}$ kyphotic angle change postoperatively. There were no differences in age, sex, C2-C7 Cobb angle, T1 slope, C2-C7 SVA, ROM from C2-C7, segmental instability, or T2 signal change. Multiple regression analysis revealed T1 slope had a strong relationship with postoperative cervical kyphosis. Likewise, correlation analysis revealed there was a statistical significance between T1 slope and postoperative Cobb angle change (p=0.035), and that there was a statistically significant relationship between T1 slope and C2-C7 SVA (p=0.001). Patients with higher preoperative T1 slope demonstrated loss of lordotic curvature postoperatively. Conclusion : Laminoplasty has a high probability of aggravating sagittal balance of the cervical spine. T1 slope is a good predictor of postoperative kyphotic changes of the cervical spine. Similarly, T1 slope is strongly correlated with C2-C7 SVA.

• Journal of Ocean Engineering and Technology
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• v.30 no.5
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• pp.389-399
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• 2016

This paper presents the explorations of hydrothermal vents located in the Marina Arc and Back Arc Basin using the deep-sea ROV Hemire. These explorations were conducted by KRISO and KIOST to demonstrate the capability of Hemire in various applications for deep-sea scientific research. The missions included the following: (1) to search the reported vents, (2) conduct visual inspections, (3) deploy/recover a sediment trap and bait traps, (4) sample sediment/water/rock, (5) measure the magnetic field at the vent site, and (6) acquire a detailed map using multi-beam sonar near the bottom. We installed three HD cameras for precise visual inspection, a high-temperature thermometer, a three-component magnetometer, and a multi-beam sonar to acquire details of the bottom contour or identify vents in the survey area. The explorations were performed in an expedition from March 23 to April 5, 2016, and the missions were successfully completed. This paper discusses the operational process, navigation, and control of Hemire, as well as the exploration results.

• Laboraroty Animal Research
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• v.34 no.4
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• pp.248-256
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• 2018

O-2-$^{18}F$-fluoroethyl-l-tyrosine ($[^{18}F]FET$) has been widely used for glioblastomas (GBM) in clinical practice, although evaluation of its applicability in non-clinical research is still lacking. The objective of this study was to examine the value of $[^{18}F]FET$ for treatment evaluation and prognosis prediction of anti-angiogenic drug in an orthotopic mouse model of GBM. Human U87MG cells were implanted into nude mice and then bevacizumab, a representative anti-angiogenic drug, was administered. We monitored the effect of anti-angiogenic agents using multiple imaging modalities, including bioluminescence imaging (BLI), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET/CT). Among these imaging methods analyzed, only $[^{18}F]FET$ uptake showed a statistically significant decrease in the treatment group compared to the control group (P=0.02 and P=0.03 at 5 and 20 mg/kg, respectively). This indicates that $[^{18}F]FET$ PET is a sensitive method to monitor the response of GBM bearing mice to anti-angiogenic drug. Moreover, $[^{18}F]FET$ uptake was confirmed to be a significant parameter for predicting the prognosis of anti-angiogenic drug (P=0.041 and P=0.007, on Days 7 and 12, respectively, on Pearson's correlation; P=0.048 and P=0.030, on Days 7 and 12, respectively, on Cox regression analysis). However, results of BLI or MRI were not significantly associated with survival time. In conclusion, this study suggests that $[^{18}F]FET$ PET imaging is a pertinent imaging modality for sensitive monitoring and accurate prediction of treatment response to anti-angiogenic agents in an orthotopic model of GBM.

• Journal of radiological science and technology
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• v.43 no.6
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• pp.475-480
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• 2020

The purpose of this study was to reconstruct diffusion tensor tractography (DTT) using stem of garlic and asparagus for in vitro phantom of diffusion tensor imaging (DTI), and to compare and evaluate the fractional anisotropy (FA) value and the apparent diffusion coefficient (ADC) value to determine whether it can be used as materials for in vitro phantoms. Among various plant fibers such as stem of garlic, palmae, cotton, asparagus, etc., stem of garlic and asparagus, which are considered to be the most suitable for making phantoms, and whose shape is considered to be the most suitable for making phantoms, were selected and tests were conducted. Holes were made in a plastic bucket at an angle of 0°, 30°, 60°, 90°, and 120°, then tubes were inserted. In the tube, asparagus and stem of garlic were inserted as far in as possible, and the inserted tube was inserted into the center of the heat bathed gelatin to harden. We were able to reproduce DTT images in asparagus and stem of garlic. Fiber tissues of asparagus and stem of garlic did not show complete connectivity, but the reconstructed images of DTT showed good connectivity. The FA values of asparagus in the tubes were 0.198 at 0° (straight), 0.207 at 30°, 0.187 at 60°, 0.231 at 90°, and 0.204 at 120°. In addition, the FA values of stem of garlic in the tubes were 0.235 at 0°, 0.236 at 30°, 0.216 at 60°, 0.218 at 90°, and 0.257 at 120°. The ADC values of asparagus in the tubes were 1.545 at 0°, 1.677 at 30°, 1.629 at 60°, 1.535 at 90°, and 1.725 at 120°. In addition, the ADC values of stem of garlic in the tubes were 1.252 at 0°, 1.396 at 30°, 1.698 at 60°, 1.756 at 90°, and 1.466 at 120°. For the best expressed DTT reconstruction image, it showed the longest connectivity in the straight line as we hypothesized. In addition, when comparing the FA values and ADC values of fiber tissues of stem of garlic and asparagus, FA value was generally higher in stem of garlic and ADC value was slightly higher in asparagus.

• Journal of the Korean Society of Radiology
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• v.15 no.4
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• pp.555-564
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• 2021

Thalamus is known to play an important role in the regulation of nerve function. Thalamus, located in the center of the brain, is involved in sleep, arousal, and emotional regulation, and has been reported to be associated with multiple sclerosis, essential tremors, and neurodegenerative diseases such as Parkinson's disease. In addition, it has been reported that iron deposits in the thalamus can cause depressive symptoms with age. Although there are discrepancies between studies, it can be deduced that the thalamus region has a clear effect on neurological disorders due to a strong relationship between the thalamus and neurological functions such as emotional control and processing. Through tractography analysis, the connectivity between the detailed areas of each subcortical region was investigated in the form of a matrix, showing strong connectivity and weak interhemispheric connectivity. In the 59> group, the WM connectivity of thalamus was found to be weaker than those of the two groups. Comparisons between the two groups showed that the young groups (10-39 and 40-59) had higher connection intensity than the 59> group and that statistically significant differences in 3 connection pathways were found in each hemisphere. A decrease in thalamus-related connection strength in aging has shown that it can affect emotional and neurological disorders such as anxiety and depression, and network measurements can help assess cognitive impairment across clinical conditions.

• Journal of the Korean Orthopaedic Association
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• v.55 no.2
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• pp.117-126
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• 2020

Total knee arthroplasty is performed widely in degenerative arthritis of the knee joint, and the frequency of use is increasing. Efforts should be made to achieve functional recovery, such as returning to daily life, and the recovery of strength and range of motion after surgery. The procedure should be approached from a range of perspectives, such as patient factors, surgical technique and rehabilitation. The patient's age, degree of obesity, sex, and strength of the quadriceps muscle can affect the functional recovery after surgery. In addition, the patient's mental state, such as expectation value and satisfaction, can also have an effect. For functional recovery, patient education, pain control, and strengthening of the quadriceps muscle can be performed prior to surgery. Postoperative physiotherapy, such as icing and compression, transcutaneous electrical nerve stimulation therapy, neuromuscular electrical stimulation therapy, low frequency low intensity magnetic field therapy, strengthening of quadriceps muscle, and range of motion exercise can also be applied. In recent years, hydrotherapy, which restores the strength and balance of the leg, is being performed increasingly. These treatments are not only performed shortly after surgery, but are also performed continuously. In addition, the surgeon should apply it appropriately considering the patient's condition, compliance, and social and psychological conditions.

• The Korean Society of Law and Medicine
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• v.23 no.2
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• pp.119-139
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• 2022

Brain stimulation technology that administers electrical and magnetic stimulation to a brain has shown a significant level of possibility for treating a wide range of various neurological and psychiatric disorders. Depending on its nature, the technology is defined either as invasive or non-invasive, and deep brain stimulation (DBS) is one of the most well-known invasive brain stimulation technologies. Currently categorized as grade 4 medical device in accordance with Guideline On Medical Devices And Their Grades, a Notification of Ministry of Food and Drug Safety (MFDS), the DBS has been used as a stable treatment for several diseases. At the same time, the DBS technology has recently achieved substantial advancement, encouraging active discussions for its use from various perspectives. On the contrary, debates over legal regulation related to the use of DBS has relatively been smaller in numbers. In this context, this article aims to 1) introduce the DBS technology and its safety in setting out the tone; 2) touch upon major legal issues that would potentially rise from its use for four different purposes of treatment, clinical study, areas of non-standard treatment where no other methods are available, and enhancement; and finally 3) highlight disputes concerning common emerging issues observed in the aforementioned four purposes from the viewpoint of legal responsibility and liability of using the DBS, which are benefit-risk assessment, physicians' duty of information, patients' capacity to consent, control for device, and insurance coverage.

• Journal of the Korean Society of Radiology
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• v.16 no.2
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• pp.177-184
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• 2022

The purpose of this study is surveyed diagnostic radiography (DR) examination in veterinary hospital (VC) including non-ionization radiation such as ultra-sonography and magnetic resonance imaging. From June 1 to June 20. 2021, we surveyed the VC in 00 metropolitan city by using a structural questionnaire which are location of VC and X-ray unit et al.. Data are expressed as a mean with standard deviation for continuous variable or percent for categorical variable using SPSS ver. 26.0. As the first animal to be visited, dogs were the highest with 61.9%, followed by cats with 12.9%. In 87.1% fo cases, DR units were used, and 4 VCs did not. In 27 VCs using DR units, 48.1% separated examination room and control room, 19.8% examined in animal visited, protective clothing was in all VCs, 55.6% were measured radiation exposure dose, 92.6% was responded a necessary for examination education. From the above results, it will help to revise the guidelines for DR units and examination in korea VCs.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.161-168
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• 2023

Converter slag is a by-product generated by refining the pig iron produced into molten steel in the blast furnace, occupying about 15 % of the weight of steel production. It has a high free-CaO content that can generate expansion cracks when used for concrete aggregate. This is the main reason to make it difficult to recycle. To solve this problem, government guideline requires that converter slag has to be aged in an open yard for 90 days. However, aging can not be perfectly performed because it entails time and cost. In this study, we tried to investigate the applicability of converter slag as a cementitious material rather than an aggregate by mixing converter slag with mortar formulations. According to the EDS results of the converter slag in the experiment, we found that screening in the aggregate phase was more effective than that in the powder phase. When the particles separated by a magnet in the aggregate state were pulverized and used for concrete up to a 15 % replacement ratio, various engineering characteristics, such as flow, length change, and compressive strength, showed engineering characteristics similar to those of the control mix.