• Journal of Korean Neurosurgical Society
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• 제61권6호
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• pp.767-773
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• 2018

Three male patients diagnosed with surfer's myelopathy (19-30 years) were admitted to our hospital. All three patients were novice surfers showing a typical clinical course of rapid progression of paraplegia following the onset of back pain. Typical history and magnetic resonance imaging features indicated the diagnosis of surfer's myelopathy. Two patients received high-dose steroid therapy and the other was treated with induced hypertension. One patient treated with induced hypertension showed almost full recovery; however, two patients who received high-dose steroid therapy remained completely paraplegic and required catheterization for bladder and bowel dysfunction despite months of rehabilitation. Our case series demonstrates the potentially devastating neurological outcome of surfer's myelopathy; however, early recovery in the initial 24-72 hours of presentation can occur in some patients, which is in accordance with previous reports. Ischemic insult to the spinal cord is thought to play a crucial role in the pathophysiology of surfer's myelopathy. Treatment recommendations include hydration, induced hypertension, early spinal angiography with intra-arterial intervention, intravenous tissue plasminogen activator, and high-dose steroid therapy; however, there is no standardized treatment option available. Early recovery appears to be important for long-term neurological outcome. Induced hypertension for initial treatment can be helpful for improving spinal cord perfusion; therefore, it is important for early and long-term neurological recovery. Education and awareness are essential for preventing surfer's myelopathy and avoiding further deterioration of neurological function.

• 대한간호학회지
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• 제48권6호
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• pp.731-742
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• 2018

Purpose: The purpose of this study was to test a hypothesis explaining direct and indirect relationships among the factors affecting self-care behaviors of kidney transplant patients, based on self-determination theory. Methods: Data were collected from 222 outpatients with kidney transplantation. The endogenous and exogenous variables of the hypothetical model consisted of healthcare provider's autonomy support, duration after kidney transplantation, basic psychological need satisfaction, autonomous and controlled motivation, depression, and self-care behaviors. Collected data were analyzed using SPSS/WIN 24.0 and AMOS 24.0. Results: The hypothetical model demonstrated a good fit: RMSEA=.06, SRMR=.04, TLI=.94, CFI=.97. Statistically significant explanatory variables for the self-care behaviors of kidney transplant patients were duration after transplantation and basic psychological need satisfaction. Healthcare provider's autonomy support was indirectly significant, while autonomous motivation, controlled motivation and depression were not statistically significant for self-care behaviors. The variables accounted for 59.5% of the self-care behaviors of kidney transplant patients. Conclusion: It is necessary to develop an autonomy support program for healthcare providers to enhance the self-care behaviors of kidney transplant patients. Preventing the deterioration of self-care behaviors will be possible by conducting this program at one year and six years post-transplantation. In addition, the results suggest the need to developing personalized autonomy support programs for healthcare providers that can meet the basic psychological need satisfaction of kidney transplant patients.

• 한국안전학회지
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• 제33권6호
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• pp.15-21
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• 2018

Ships may collide with reefs or other objects during operation, when arriving or departing ports. The hull plate may be damaged due to the contact with other ships. The total number of domestic powered fishing vessels has decreased, but that of FRP fishing vessels has increased by 0.7% and the ratio of FRP fishing vessels to the total fishing vessels increased to 96%. Recently, fishing vessels has been used as fishing boats for income of non-fishermen as well as fishermen. Therefore, safety management for repair and maintenance is necessary. The penetration of moisture and moisture in the composite material such as FRP may deteriorate the mechanical properties and the salt (NaCl) component of the damaged portion may cause a relatively high deterioration in material strength. The gel coat painting is the final stage of repairs ans maintenance of FRP fishing vessels. The thickness criteria in the domestic and foreign gel coat is 0.3~0.762 mm. The joint specimens, which was immersed in seawater for 120 days, were compared with those without seawater immersion. As a result, the tensile strength was 83 ~ 121.8% and the flexural strength was 83 ~ 113% compared with the specimens without seawater immersion. According to the previous study the tensile strength decreased by more than 29% and the flexural strength decreased by more than 50% when the composite material was immersed in seawater for 1,083 hours without coating. As a result, it was found that the gel coat with 0.5 mm thickness is very effective in preventing the strength decrease of the composite material.

• 한국식품영양학회지
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• 제33권6호
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• pp.614-623
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• 2020

The objective of this study was to produce a nutrient delivery system (NDS) using sialic acid extracted from edible bird's nest (EBN), which improves brain function in patients with Alzheimer's disease and Parkinson's disease, by affinity bead technology (ABT). The inhibitory activity of acetylcholinesterase (AChE) and pyramidal cells in the dentate gyrus of the hippocampus were analyzed to investigate the effect of a sialic acid NDS on Alzheimer's disease. Also, the effect of a sialic acid NDS on Parkinson's disease was evaluated by rota-rod test and pole test in an animal model. Among the groups treated with donepezil, EBN, and sialic acid NDS, the AChE activity was the lowest in the sialic acid NDS-treated group. The results of the hippocampus analysis of the rat model confirmed that the sialic acid NDS inhibited amyloid-beta accumulation depending upon the concentration. Also, the sialic acid NDS group showed more improvement in motor deterioration than the1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced group in both the rota-rod test and pole test. Therefore, the sialic acid NDS had an effect of protecting not only Alzheimer's disease by inhibiting AChE and amyloid-beta accumulation, but Parkinson's disease by preventing neurotoxicity induced by MPTP.

• 보건행정학회지
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• 제32권2호
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• pp.173-179
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• 2022

Background: This study aimed to identify patterns of elderly patients who transferred from long-term care hospitals to emergency rooms and provide the evidence of emergency medical systems to prepare for a super-aged society. Methods: The data source was the National Emergency Department Information System database from January 2014 to December 2019 in Korea. We performed a cross-sectional study among elderly patients (≥65 years) who transferred from a long-term care hospital to an emergency room. Trend analysis was conducted by year. Results: We identified 225,765 elderly patients who were transferred from long-term care hospitals to emergency rooms between January 1, 2014 and December 31, 2019. The proportion of the study population and their mean age were recently increased (p<0.001, respectively). The proportion of elderly patients being re-transferred (p=0.049) and the patients re-transferred to long-term care hospitals is significantly increased (p=0.005). Conclusion: The establishment of efficient emergency medical services for an aging society is important. It is necessary to develop a healthcare network with the government, long-term care hospitals, and medical institutions in the community suitable for preventing disease deterioration.

• 디지털융복합연구
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• 제20권5호
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• pp.593-598
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• 2022

최근 데이터의 생산량은 폭발적인 증가를 이루어왔고, 빅데이터를 안전하고 빠르게 저장하기 위한 대용량 저장 시스템이 다양하게 발전하고 있다. 저장시스템의 대표적인 구성은 빠른 데이터 처리속도를 가지고 있는 SSD를 신뢰성 높은 데이터 유지 보수가 가능한 RAID 그룹으로 사용하는 것이다. 그러나 SSD를 구성하는 낸드 플래시 메모리는 특정 횟수 이상 쓰기를 반복할 경우 열화가 발생하는 특징이 있기 때문에 RAID 그룹의 여러 SSD에서 동시에 불량이 발생할 가능성을 증가시킬 수 있다. 그리고 이러한 동시성 불량은 데이터를 복구할 수 없는 심각한 신뢰성의 문제를 초래할 수 있다. 따라서 본 논문에서는 이러한 문제를 해결하기 위해 RAID 그룹 내에서 각 SSD가 차등으로 수명 마감이 유도되도록 IO를 조절하는 방법을 제안한다. 본 논문에서 제안하는 기법은 SMART를 활용하여 각 SSD의 상태와 사용된 데이터 패턴에 따라 할당되는 IO 횟수를 단계별로 조절한다. 그리고 이 방법은 SSD의 차등 수명마감을 유도하기 때문에 RAID에서 대량의 동시성 불량이 발생하는 것을 방지하는 장점이 있다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.115-117
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• 2022

화이트박스 암호 기법은 암호 키 정보를 소프트웨어 기반 암호화 알고리즘에 섞어 암호 키의 노출을 막는 방식이다. 화이트박스 암호 기법은 허가되지 않은 역공학 분석으로 메모리에 접근하여 기밀 데이터와 키를 유추하기 어렵게 만들어서 종래의 하드웨어 기반의 보안 암호화 기법을 대체하는 기술로 주목받고 있다. 하지만, 암복호화 과정에서 연산 결과와 암호 키를 숨기기 위해 크기가 큰 룩업테이블을 사용하기 때문에 암복호 속도가 느리고, 메모리 사이즈가 커지는 문제가 발생한다. 특히 최근 저가, 저전력, 경량의 사물인터넷 제품들은 제한된 메모리 공간과 배터리 용량 때문에 화이트박스 암호을 적용하기 어렵다. 또한, 실시간 서비스를 지원해야 하는 네트워크 환경에서는 화이트박스 암호의 암복호화 속도로 인해 응답 지연 시간이 증가하여 통신 효율이 열화된다. 따라서 본 논문에서는 S.Chow가 제안한 AES 기반 화이트박스(WBC-AES)를 사용하여 속도와 메모리 요구조건을 만족할 수 있는지 실험 결과를 토대로 분석한다.

• Advances in nano research
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• 제15권4호
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• pp.355-366
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• 2023

Biological corrosion, a crucial aspect of metal degradation, has received limited attention despite its significance. It involves the deterioration of metals due to corrosion processes influenced by living organisms, including bacteria. Soil represents a substantial threat to pipeline corrosion as it contains chemical and microbial factors that cause severe damage to water, oil, and gas transmission projects. To combat fouling and corrosion, corrosion inhibitors are commonly used; however, their production often involves expensive and hazardous chemicals. Consequently, researchers are exploring natural and eco-friendly alternatives, specifically nano-sized products, as potent corrosion inhibitors. This study aims to environmentally synthesize silver nanoparticles using an extract from Lagoecia cuminoides L and evaluate their effectiveness in preventing biological corrosion of buried pipes in soil. The optimal experimental conditions were determined as follows: a volume of 4 ml for the extract, a volume of 4 ml for silver nitrate (AgNO3), pH 9, a duration of 60 minutes, and a temperature of 60 degrees Celsius. Analysis using transmission electron microscopy confirmed the formation of nanoparticles with an average size of approximately 28 nm, while X-ray diffraction patterns exhibited suitable peak intensities. By employing the Scherer equation, the average particle size was estimated to be around 30 nm. Furthermore, antibacterial studies revealed the potent antibacterial activity of the synthesized silver nanoparticles against both aerobic and anaerobic bacteria. This property effectively mitigates the biological corrosion caused by bacteria in steel pipes buried in soil.

• 한국전문물리치료학회지
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• 제30권4호
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• pp.306-313
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• 2023

Background: As social problems due to the acceleration of the aging era and the increase in the elderly population are becoming serious, virtual reality (VR)-based healthcare is emerging as an approach for preventing and managing health issues. Objects: This study used validity and reliability analyses to examine the clinical efficacy that is, the clinical value and usability of a novel VR cognitive evaluation system index that we developed. Methods: We developed a VR cognitive evaluation system based on motion recognition analysis evaluation for individuals aged 65 to 85. After conducting the Korean version of the Mini-Mental State Exam (K-MMSE) cognitive evaluation, the evaluation score was verified through correlation analysis in the VR cognitive evaluation system. To verify the construct validity of the two groups, the Global Deterioration Scale (GDS) grades were categorized into a normal cognitive group (GDS grade 1) and a cognitive impairment group (GDS grades 2 and 3). The data were measured twice to determine the reliability between the two measurements and assess the stability and clinical value of the evaluation system. Results: Our evaluation system had a high correlation of 0.85 with the widely used K-MMSE cognitive evaluation. The system had strong criterion-related validity at the 95% confidence interval. Compared to the average score of GDS grade 1 in the VR cognitive evaluation system, the average score of GDS grades 2 and 3 in the VR cognitive evaluation system was statistically significantly lower while also having strong construct validity at the 95% confidence interval. To measure the reliability of the VR cognitive evaluation system, tests-retests were conducted using the intraclass correlation coefficient (3,1), which equaled 0.923 and was statistically significant. Conclusion: The VR cognitive evaluation system we developed is a valid and reliable clinical tool to distinguish between normal cognitive status and mild cognitive impairment.

• 반도체디스플레이기술학회지
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• 제22권3호
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• pp.130-135
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• 2023

Plasma-resistant ceramic (PRC) is a material used to prevent internal damage in plasma processing equipment for semiconductors and displays. The challenge is to suppress particles falling off from damaged surfaces and increase retention time in order to improve productivity and introduce the latest miniaturization process. Here, we confirmed the effect of suppressing plasma deterioration and reducing the etch rate through surface treatment of existing PRC with an initial illumination level of 200 nm. In particular, quartz glass showed a decrease in etch rate of up to 10%. Furthermore, it is believed that micro-scale secondary particles formed on the microstructure of each material grow as crystals during the fluoridation process. This is a factor that can act as a killer defect when dropped, and is an essential consideration when analyzing plasma resistance. The plasma etching suppression effect of the initial illumination is thought to be due to partial over etching at the dihedral angle of the material due to the sputtering of re-emission of Ar+-based cations. This means that plasma damage due to densification can also be interpreted in existing PRC studies. The research results are significant in that they present surface treatment conditions that can be directly applied to existing PRC for mass production and a new perspective to analyze plasma resistance in addition to simple etching rates.