• Journal of Korean Neurosurgical Society
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• v.41 no.6
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• pp.382-386
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• 2007

Objective : Various techniques of cervical laminoplasty have been developed to decompress the spinal canal in patients with multilevel cervical spondylotic myelopathy. This study compared the early surgical outcomes between unilateral open-door laminoplasty and midline splitting cervical laminoplasty. Materials and Methods : From March 2004 to August 2005, we performed cervical laminoplasty in 34 patients with cervical myelopathy. Of these patients, 24 were treated by unilateral open-door laminoplasty [open-door group] and 10 by midline splitting cervical laminoplasty [splitting group]. The mean duration of follow up was 9.2 months in the open-door group and 15.8 months in the splitting group. We retrospectively analyzed neurological outcomes using the Japanese Orthopedic Association [JOA] score, and compared the radiological changes between the two groups. Results : Postoperative JOA score and recovery rate were $13.29{\pm}4.01$ and $56.28{\pm}44.91%$ in the open-door group and $15.75{\pm}0.88$ and $72.69{\pm}19.99%$ in the splitting group. There was no statistical difference between the two groups [p>0.05]. Regarding the radiological assessment, the increase of postoperative axial canal area was $63.23{\pm}23.24%$ in the open-door group and $42.30{\pm}14.96%$ in the splitting group [p<0,05]. Conclusion : There was no statistical difference in the neurological outcome when the early surgical outcomes of the open-door group and the splitting group were compared. However, the open-door group showed wider cervical spinal canal areas than the splitting group.

• Journal of Oriental Neuropsychiatry
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• v.30 no.1
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• pp.31-38
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• 2019

Objectives: To identify the cost effectiveness of early dementia diagnosis using the 2014 Health Insurance Review & Assessment Service-National Patients Sample (HIRA-NPS). Methods: The medical costs of dementia between Western medical care and Korean medical care were compared through the reimbursement and non-reimbursement item code for dementia examination. In addition, the medical expenses of patients with dementia and mild cognitive impairment were compared and analyzed with respect to Western and Korean medical care. Results: There were 87,434 claims, of which 16,101 patients were diagnosed with dementia and 38,680,789,560 won was found to be the medical expenses. 12,881 patients (80.0%) with dementia, 3,144 patients (19.5%) with mild cognitive impairment, and 76 patients (0.5%) progressing from mild cognitive impairment to dementia. The proportion of medical expenses was 97.6% for dementia patients, 2.3% for mild cognitive impairment, and 1% for patients progressing from mild cognitive impairment to dementia. 86,070 claims (98.4%) were from Western medical care, with16,824 patients (98.2%), and the medical expenses was 38,546,895,400 won (99.7%). 1,361 claims (1.6%) were from Korean medical care, with 303 patients (1.8%), and the medical expenses was 133,894,160 won (0.3%). Conclusions: This study compared and analyzed the medical costs of dementia patients and the diagnosis of both Korean and Western medical care. The results of this study are expected to be used as basic research data for investigating cost effectiveness of developing early diagnosis of dementia.

• International Journal of Computer Science & Network Security
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• v.23 no.8
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• pp.17-25
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• 2023

The alarming global prevalence of Type 2 Diabetes Mellitus (T2DM) has catalyzed an urgent need for robust, early diagnostic methodologies. This study unveils a pioneering approach to predicting T2DM, employing the Extreme Gradient Boosting (XGBoost) algorithm, renowned for its predictive accuracy and computational efficiency. The investigation harnesses a meticulously curated dataset of 4303 samples, extracted from a comprehensive Chinese research study, scrupulously aligned with the World Health Organization's indicators and standards. The dataset encapsulates a multifaceted spectrum of clinical, demographic, and lifestyle attributes. Through an intricate process of hyperparameter optimization, the XGBoost model exhibited an unparalleled best score, elucidating a distinctive combination of parameters such as a learning rate of 0.1, max depth of 3, 150 estimators, and specific colsample strategies. The model's validation accuracy of 0.957, coupled with a sensitivity of 0.9898 and specificity of 0.8897, underlines its robustness in classifying T2DM. A detailed analysis of the confusion matrix further substantiated the model's diagnostic prowess, with an F1-score of 0.9308, illustrating its balanced performance in true positive and negative classifications. The precision and recall metrics provided nuanced insights into the model's ability to minimize false predictions, thereby enhancing its clinical applicability. The research findings not only underline the remarkable efficacy of XGBoost in T2DM prediction but also contribute to the burgeoning field of machine learning applications in personalized healthcare. By elucidating a novel paradigm that accentuates the synergistic integration of multifaceted clinical parameters, this study fosters a promising avenue for precise early detection, risk stratification, and patient-centric intervention in diabetes care. The research serves as a beacon, inspiring further exploration and innovation in leveraging advanced analytical techniques for transformative impacts on predictive diagnostics and chronic disease management.

• Korean Journal of Radiology
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• v.24 no.5
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• pp.444-453
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• 2023

Objective: Meningeal lymphatic vessels are predominantly located in the parasagittal dural space (PSD); these vessels drain interstitial fluids out of the brain and contribute to the glymphatic system. We aimed to investigate the ability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the dynamic changes in the meningeal lymphatic vessels in PSD. Materials and Methods: Eighteen participants (26-71 years; male:female, 10:8), without neurological or psychiatric diseases, were prospectively enrolled and underwent DCE-MRI. Three regions of interests (ROIs) were placed on the PSD, superior sagittal sinus (SSS), and cortical vein. Early and delayed enhancement patterns and six kinetic curve-derived parameters were obtained and compared between the three ROIs. Moreover, the participants were grouped into the young (< 65 years; n = 9) or older (≥ 65 years; n = 9) groups. Enhancement patterns and kinetic curve-derived parameters in the PSD were compared between the two groups. Results: The PSD showed different enhancement patterns than the SSS and cortical veins (P < 0.001 and P < 0.001, respectively) in the early and delayed phases. The PSD showed slow early enhancement and a delayed wash-out pattern. The six kinetic curve-derived parameters of PSD was significantly different than that of the SSS and cortical vein. The PSD washout rate of older participants was significantly lower (median, 0.09; interquartile range [IQR], 0.01-0.15) than that of younger participants (median, 0.32; IQR, 0.07-0.45) (P = 0.040). Conclusion: This study shows that the dynamic changes of meningeal lymphatic vessels in PSD can be assessed with DCE-MRI, and the results are different from those of the venous structures. Our finding that delayed wash-out was more pronounced in the PSD of older participants suggests that aging may disturb the meningeal lymphatic drainage.

• Hip & pelvis
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• v.35 no.3
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• pp.206-215
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• 2023

Purpose: Delay in performance of hip fracture surgery can be caused by medical and/or administrative reasons. Although early surgery is recommended, it is unclear what constitutes a delayed surgery and whether the impact of delayed surgery can differ depending on the reason for the delay. Materials and Methods: A total of 269 consecutive hip fracture patients over 50 years of age who underwent surgery were prospectively enrolled. They were divided into two groups: early and delayed (time from reaching the hospital to surgery less than or more than 48 hours). Patients were also categorized as fit or unfit based on anesthetic fitness. One-year mortality was recorded, and regression analyses were performed to assess the impact of delay on mortality. Results: A total of 153 patients (56.9%) had delayed surgery with a mean time to surgery of 87±70 hours. A total of 115 patients (42.8%) were considered medically fit to undergo surgery. No difference in one-year mortality was observed between patients with early surgery and those with delayed surgery (P=0.854). However, when assessment of the time to surgery was performed in a continuous manner, mortality increased with prolonged time to surgery, particularly in unfit patients, and higher mortality was observed when the delay exceeded six days (fit: P=0.117; unfit: P=0.035). Conclusion: The effect of delay on mortality was predominantly observed in patients who were not considered medically fit, suggesting that surgical delays might have a greater impact on patients with medical reasons for delay.

• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.189-197
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• 2003

The Level 3 PSA being termed accident consequence analysis is defined to assess effects on health and environment caused by radioisotopes released from severe accidents of nuclear power plants. In this study consequence analysis on health effects depending on release characteristics of radioisotopes has been peformed using the 3 MACCS code in severe accidents. The results of this study may contribute to identifying the relative importance of various parameters occurred in consequence analysis as well as to assessing risk reduction accident management strategies. Especially three parameters for the purpose of consequence analysis, such as the release height, the heat content, and the duration time, are used to analyze the variation of early fatalities and latent cancer fatalities. Also, in this study risk assessment using the concept, 'products of uncertainty and consequences', has been performed using consequence of MACCS and frequency on source term category 19 scenarios from IPE (Individual Plant Examination) analysis.

• Environmental Engineering Research
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• v.11 no.5
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• pp.277-284
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• 2006

The genetic toxicity of environmental pollutants, namely, nonylphenol (NP), bisphenol A (BPA) and chloropyriphos (CP) was investigated in aquatic sentinel species, freshwater crustacean, Daphnia magna, and larva of aquatic midge, Chironomus tentans, using Comet assay. Physiological effect of such pollutants was also investigated by studying the specimens' rates of reproduction, growth and survival. Acute toxicity results showed that, as expected, Daphnia was more sensitive than Chironomus to chemical exposure. The order of acute toxicity was CP > NP > BPA in D. magna and NP > CP > BPA in C. tentans. BPA may exert a genotoxic effect on D. magna and C. tentans, given that DNA strand breaks increased in both species exposed to this compound, whereas NP- and CP-induced DNA damage occurred only in C. tentans. In vivo genotoxic data obtained in aquatic sentinel species could provide valuable information for freshwater quality monitoring. The experiments with NP-exposed D. magna showed that the pollutant has long-term effects on reproduction, whereas no short-term effect on DNA integrity was found, being an example of a false-negative result from the biomarkers perspective. This result could be interpreted that other mechanism than genetic alteration might be involved in NP-induced reproduction failure in D. magna. False-positive results from the genotoxic biomarker obtained in BPA-exposed D. magna and in NP-exposed C. tentans make it difficult to use DNA integrity as an early warning biomarker. However, as the mere presence of genotoxic compounds, which are potentially carcinogenic, is of high concern to human and ecosystem health, it could also be important to rapidly and effectively detect genotoxic compounds in the aquatic system in ways that do not necessarily accompany a higher level of alteration. Considering the potential of D. magna and C. tentans as bioindicator species, and the importance of genotoxic biomarkers in ecotoxicity monitoring, DNA damage in these species could provide useful information for environmental risk assessment.

• The Journal of the Acoustical Society of Korea
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• v.22 no.6
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• pp.512-518
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• 2003

In this paper, resonance durability analysis is performed for the fatigue life assessment considering vibration effect of a vehicle system. In the resonance durability analysis, the frequency response and the dynamic load on frequency domain are used. Multi-body dynamic analysis, finite element analysis, and fatigue life prediction method are applied for the virtual durability assessment. To obtain the frequency response and the dynamic load history, the computer simulations running over typical pothole and Belgian road are carried out by utilizing vehicle dynamic model. The durability estimations on the rear suspension system of the passenger car are performed by using the resonance durability analysis technique and compared with the quasi-static durability analysis. The study shows that the fatigue life considering resonant frequency of vehicle system can be effectively estimated in early design stage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.151-160
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• 2020

Various smart city projects have been actively promoted as important policies of governments in various countries. The key to the success of smart cities led by governments is to develop sustainable governance through the expansion and proliferation of outcomes. This study comparatively analyzed the smart city policies of the USA and Europe from viewpoints of outcome expansion and proposed policy directions for smart cities in Korea. The comparison items were case cities, the expansion of smart city technologies and services, the measurement of outcomes, the accumulation of knowledge and information, and standardization. This study found that the items of each index were linked for the purpose of assessment, expansion, and the creation of successful cases in the USA and Europe. Based on our analysis, four policy directions were proposed that included the early provision of follow-up measures for case cities, the development of a project performance assessment system, the provision of an integrated knowledge accumulation system, and an earnest promotion of industry activation policies.

• Korean Journal of Environmental Agriculture
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• v.31 no.1
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• pp.75-95
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• 2012

BACKGROUND: Increase of heavy metals in agricultural ecosystem has become a social issue nationwide as it is related to public health. This review was performed to find out more systematic and integrated future researches on heavy metals using up to date articles published in the Korean journals related to agricultural environment. METHODS AND RESULTS: Researches on heavy metals in agricultural soils and plant uptake were categorized by the establishment of criteria, analytical methods, monitoring, management of source, characteristics and behavior in soil, plant uptake, bioavailability affecting physico -chemical properties in soil, risk assessment and soil remediation. In the early 1990s, the monitoring for heavy metals in soil has been widely performed. Accumulation of heavy metals in contaminated soil and availability to plants has also attracted interests to study the soil remediation using various physico-chemical methods. The phytoavailability and phytotoxicity of heavy metals have been mainly studied to assess the safety of agro-products using risk assessment techniques in the 2000s. CONCLUSION: Future direction of research on heavy metal in agricultural environment must be carried out by ensuring food safety and sustainability. A steady survey and proper management for polluted regions should be continued. Law and regulation must be modified systematically. Furthermore, studies should expand on mitigation of heavy metal uptake by crops and remediation of polluted fields.