• Journal of Korean Neurosurgical Society
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• v.62 no.2
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• pp.136-143
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• 2019

Moyamoya disease (MMD) is a progressive cerebrovascular disease with unknown etiology, characterized by bilateral steno-occlusive changes at the terminal portion of the internal carotid artery and an abnormal vascular network formation at the base of the brain. MMD has an intrinsic nature to convert the vascular supply for the brain from internal carotid (IC) system to the external carotid (EC) system, as indicated by Suzuki's angiographic staging. Insufficiency of this 'IC-EC conversion system' could result not only in cerebral ischemia, but also in intracranial hemorrhage from inadequate collateral anastomosis, both of which represent the clinical manifestation of MMD. Surgical revascularization prevents cerebral ischemic attack by improving cerebral blood flow, and recent evidence further suggests that extracranial-intracranial bypass could powerfully reduce the risk of re-bleeding in MMD patients with posterior hemorrhage, who were known to have extremely high re-bleeding risk. Although the exact mechanism underlying the hemorrhagic presentation in MMD is undetermined, most recent angiographic analysis revealed the characteristic angio-architecture related to high re-bleeding risk, such as the extension and dilatation of choroidal collaterals and posterior cerebral artery involvement. We sought to update the current management strategy for hemorrhagic MMD, including the outcome of surgical revascularization for hemorrhagic MMD in our institute. Further investigations will clarify the optimal surgical strategy to prevent hemorrhagic manifestation in patients with MMD.

• Journal of Korea Trade
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• v.26 no.8
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• pp.1-20
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• 2022

Purpose - The paper aims to develop the theory of TAM and perceived risk through a more comprehensive and rigorous understanding of the influencing factors of the consumer's adoption of LG HomNet smart home from the perspective of trade-offs. Design/methodology - Based on the TAM and perceived risk theory, combined with the individual characteristics of consumers in the context of information technology as the external factors of the technology acceptance model, this paper constructs a theoretical model of the factors affecting the use intention of the consumer. It was empirically tested by using SEM, and survey data was collected from 458 respondents. Findings - The research results show that 9 hypotheses of the research model are supported and have reliable prediction accuracy. Consumers' perceived interest, perceived connectivity and perceived controllability have a significant positive impact on their intention to use. In addition, this paper also confirmed the mediating effect of perceived usefulness and perceived ease of use. Originality/value - Consumers are very concerned about gains and losses. Low-level performance risks, security risks, and financial risks will drive the consumer to have a stronger intention to use, and financial risks have the strongest impact. This research provides a useful implication and guidance for smart home equipment manufacturers and service providers in product and service innovation and marketing and promotion strategies.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.728-735
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• 2022

Roofers get exposed to increased risk of knee musculoskeletal disorders (MSDs) at different phases of a sloped shingle installation task. As different phases are associated with different risk levels, this study explored the application of machine learning for automated classification of seven phases in a shingle installation task using knee kinematics and roof slope information. An optical motion capture system was used to collect knee kinematics data from nine subjects who mimicked shingle installation on a slope-adjustable wooden platform. Four features were used in building a phase classification model. They were three knee joint rotation angles (i.e., flexion, abduction-adduction, and internal-external rotation) of the subjects, and the roof slope at which they operated. Three ensemble machine learning algorithms (i.e., random forests, decision trees, and k-nearest neighbors) were used for training and prediction. The simulations indicate that the k-nearest neighbor classifier provided the best performance, with an overall accuracy of 92.62%, demonstrating the considerable potential of machine learning methods in detecting shingle installation phases from workers knee joint rotation and roof slope information. This knowledge, with further investigation, may facilitate knee MSD risk identification among roofers and intervention development.

• Ocean Systems Engineering
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• v.12 no.3
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• pp.267-284
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• 2022

A subsea pipeline designed across active shipping lane prones to failure against external interferences such as anchorage activities, hence risk assessment is essential. It requires quantifying the geometric probability derived from ship traffic distribution based on Automatic Identification System (AIS) data. The actual probability density function from historical vessel traffic data is ideal, as for rapid assessment, conceptual study, when the AIS data is scarce or when the local vessels traffic are not utilised with AIS. Recommended practices suggest the probability distribution is assumed as a single peak Gaussian. This study compares several fitted Gaussian distributions and Monte Carlo simulation based on actual ship traffic data in main ship direction in an active shipping lane across a subsea pipeline. The results shows that a Gaussian distribution with five peaks is required to represent the ship traffic data, providing an error of 0.23%, while a single peak Gaussian distribution and the Monte Carlo simulation with one hundred million realisation provide an error of 1.32% and 0.79% respectively. Thus, it can be concluded that the multi-peak Gaussian distribution can represent the actual ship traffic distribution in the main direction, but it is less representative for ship traffic distribution in other direction. The geometric probability is utilised in a quantitative risk assessment (QRA) for subsea pipeline against vessel anchor dropping and dragging and vessel sinking.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.421-427
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• 2023

Bladder exstrophy is a rare congenital condition of the pelvis, bladder, and lower abdomen that opens the bladder against the abdominal wall, produces aberrant growth, short penis, upward curvature during erection, wide penis, and undescended testes. Exstrophy affects 1/30,000 newborns. The bladder opens against the abdominal wall in bladder exstrophy, a rare genitourinary condition. This study is vital to provide appropriate therapy choices as a basis to improve patient outcomes. This study may explain bladder exstrophy and provide treatment. Epispadias, secretory placenta, cloacal exstrophy, and other embryonic abnormalities comprise the exstrophy-spades complex. The mesenchymal layer does not migrate from the ectoderm and endoderm layers in the first trimester, affecting the cloacal membrane. Embryological problems define the exstrophy-aspidistra complex, which resembles epimedium, classic bladder, cloacal exstrophy, and other diseases. Urogenital ventral body wall anomalies expose the bladder mucosa, causing bladder exstrophy. Genetic mutations in the Hedgehog cascade pathway, Wnt signal, FGF, BMP4, Alx4, Gli3, and ISL1 cause ventral body wall closure and urinary bladder failure. External factors such as high maternal age, smoking moms, and high maternal body mass index have also been associated to bladder exstrophy. Valproic acid increases bladder exstrophy risk; chemicals and pollutants during pregnancy may increase bladder exstrophy risk. Bladder exstrophy has no identified cause despite these risk factors. Exstrophy reconstruction seals the bladder, improves bowel function, reconstructs the vaginal region, and restores urination.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.1
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• pp.75-80
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• 2023

The prevalence of aneurysm formation in adults with Moyamoya disease (MMD) is higher than that in the general population. The treatment strategy is often individualized based on the patient's disease characteristics. A 22-year-old man was diagnosed with MMD after presenting a small thalamic intracerebral and subarachnoid hemorrhage in the quadrigeminal cistern. Cerebral angiography revealed a small aneurysm (2.42 mm) in the left anterior choroidal artery. Since the hemodynamics in the left hemisphere was compromised, an indirect bypass surgery was performed. The patient's condition deteriorated postoperatively because of poor perfusion of the internal carotid artery, and massive hydration was required. During neurocritical care, the aneurysm increased in size (5.33 mm). An observation strategy was adopted because of the distal aneurysmal location and the high risk involved. Subsequently, the patient recovered, and newly developed collateral flow appeared from the external carotid artery. Additionally, a dramatic size reduction of the aneurysm (1.51 mm) was noticed. Our case suggests that MMD-related dissecting aneurysms on a distal cerebral artery, which present a high risk of embolization, could be managed by indirectly reducing the hemodynamic burden. Massive hydration in such cases should be avoided or balanced to avoid the risk of rapid growth and aneurysm rupture.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.1
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• pp.60-70
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• 2007

Statement of problem: The cement-type abutment would be needed for the reduction of its body in order to correct the axis and to assure occlusal clearance. In the case of intraoral preparation, there is a potential risk that generated heat could be transmitted into the bone-implant interface, where it can cause deterioration of tissues around the implant and failed osseointegration. Purpose: The purpose of this study was to assess the difference of the heat transmitting effect on external and internal connection implant types under various conditions. Material and method: For evaluating the effects of alternating temperature, the thermocoupling wires were attached on 3 areas of the implant fixture surface corresponding to the cervical, middle, and apex. The abutments were removed 1mm in depth horizontally with diamond burs and were polished for 30 seconds at low speed with silicone points using pressure as applied in routine clinical practice. Obtained data were analyzed using Mann-Whitney rank-sum test and Wilcoxon / Kruskal-Wallis Tests. Result: Increased temperature on bone-implant interface was evident without air-water spray coolant both at high speed reduction and low speed polishing (p<.05). But, the difference between connection types was not shown. Conclusion: The reduction procedure of abutment without using proper coolant leads to serious damage of oral tissues around the implant irrespective of external and internal connection type.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2717-2726
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• 2013

This study was conducted in order to analyze the theories behind external protective factors. In particular, it sought to understand the influence of adolescent resilience on learning motivation. Students of a public high school located in Gyeonggi Province participated in various questionnaires during the week of March 5th, 2013. Frequency analysis, one-way ANOVA (analysis of variance), correlation analysis, and multiple regression analysis were utilized to analyze the acquired data. The results revealed that when family relationships were strong and local community expectations were high, the students' 'attention to implementation processes,' one aspect of intrinsic motivation to learn, was also high. 'Suitable levels of adventurousness and risk-taking,' another aspect of intrinsic motivation to learn, was high when school expectations were also high and when relationships at the school level were weaker. The study results verified that the theory that intrinsic motivation to learn can be enhanced by strengthening external factors to protect adolescent resilience. This study is significant in that it establishes theoretical grounds to address adolescent issues, to develop programs to prevent school dropouts, and to apply the results to future legislative policies.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.240-250
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• 2013

The early detection of suicidal ideation is essential for the prevention of suicide. This study aimed to develop a brief screening tool that can be easily administered in medical settings. The Suicide Risk Screening Tool was designed for use by physicians to provide a screening process that would be reliable, standardized, quick and feasible to implement. A 2-item screening tool was derived from the Screening for Depression and Thoughts of Suicide in the Norton Sound region of Alaska, USA. The scale was modified to reflect the current situation in Korea including the elimination of the personal identification number, and was labeled the Korean Suicide Risk Screening Tool. Its reliability and applicability for medical setting were examined by explanatory study of 7 clinicians. Its validity was examined among a further 325 patients of four different medical institutions, using the results of interviewer-administered survey included demographic, clinical characteristics, and present mental status as the external criterion. A brief 2-item suicide risk screening tool can be used by mental and non-mental health clinicians to accurately detect suicidality in patients.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.139-147
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• 2015

This study deals with actual commuting distance and influence of risk factors depending on commuting distance and mode in order to reestablish actual commuting zone of primary school students. Data mining analysis(CHAID) was applied for this reestablishment using survey results from 6,927 primary school students in Seoul Metro. Six risk factors; convenience level of commuting path condition, convenience level of road crossing condition, vehicle speed on commuting path, segregation level between commuter and vehicle, congestion level of commuting path, and public security level and two mode; walking and cycle are considered in the analysis. As the results of CHAID analysis, commuting distance was divided into four zones; Internal Zone(0.491km under), External Zone(0.492 ~ 1.492km, 1.493 ~ 2.699km), Commutable Zone(2.70km over), and awareness level on safety is declined as commuting distance is increased. The risk factor affecting on safety is recognized differently by students depending on commuting distance and mode. For students commuting by walking, vehicle speed on commuting path and convenience level of commuting path condition are recognized as the prime risk factor within Internal Zone and Commutable Zone, respectively. For students commuting by cycle, convenience level of road crossing condition and vehicle speed on commuting path are recognized as the prime risk factor within Commutable Zone. Analysis results show that improved plan and program for commuting path for primary school students are required considering actual commuting distance and method.