• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.173-173
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• 2023

The Mekong River Basin (MRB) is a crucial watershed in Asia, impacting over 60 million people across six developing nations. Accurate satellite-based precipitation products (SPPs) are essential for effective hydrological and watershed management in this region. However, the performance of SPPs has been varied and limited. The APHRODITE product, a unique gauge-based dataset for MRB, is widely used but is only available until 2015. In this study, we present a novel framework for correcting SPPs in the MRB by employing a deep learning approach that combines convolutional neural networks and encoder-decoder architecture to address pixel-by-pixel bias and enhance accuracy. The DLF was applied to four widely used SPPs (TRMM, CMORPH, CHIRPS, and PERSIANN-CDR) in MRB. For the original SPPs, the TRMM product outperformed the other SPPs. Results revealed that the DLF effectively bridged the spatial-temporal gap between the SPPs and the gauge-based dataset (APHRODITE). Among the four corrected products, ADJ-TRMM demonstrated the best performance, followed by ADJ-CDR, ADJ-CHIRPS, and ADJ-CMORPH. The DLF offered a robust and adaptable solution for bias correction in the MRB and beyond, capable of detecting intricate patterns and learning from data to make appropriate adjustments. With the discontinuation of the APHRODITE product, DLF represents a promising solution for generating a more current and reliable dataset for MRB research. This research showcased the potential of deep learning-based methods for improving the accuracy of SPPs, particularly in regions like the MRB, where gauge-based datasets are limited or discontinued.

• The Journal of Internal Korean Medicine
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• v.44 no.5
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• pp.1033-1040
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• 2023

Objectives: The aim of this study is to describe the effects of traditional Korean medicine treatment on a patient with vascular dementia caused by an intracerebral hemorrhage. Methods: The patient was treated with herbal medicine (modified Guibi-tang) and acupuncture. The effects of these treatments were evaluated using the Korean Mini Mental Status Examination (K-MMSE-2), Cognitive Dementia Rating (CDR), Manual Muscle Test (MMT), Korean version of Modified Barthel Index (K-MBI), and Videofluoroscopic Swallow Study (VFSS). Results: After treatment, the K-MMSE-2 score, CDR score, MMT, K-MBI, and VFSS improved. Conclusion: The results suggest that traditional Korean medicine may be effective for the symptoms of vascular dementia caused by intracerebral hemorrhage.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.782-787
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• 2023

Korea augmentation satellite system (KASS) integration, verification, qualification (IVQ) activity is verification of requirements for KASS system and its sub-system that were performed based on the inspection, analysis, review of design, test (IART) method from factory acceptance test (FAT) to test readiness review (TRR) after critical design review (CDR) was closed. In the FAT phase, developed equipment was installed on the test platform and we were verified interfaces between sub-systems and coupling test with the kass control station (KCS). In the site aceeptance test (SAT) phase, on-site verification was conducted by installing equipment verified by FAT such as kass reference station (KRS), kass processing station (KPS), kass uplink station (KUS), KCS. However, considering the developed plan and status, SAT was divided into 3 phases and coupling test was performed. In the TRR phase, the KASS system verification was performed through FAT's test list and additional test list using the satellite based augmentation system (SBAS) broadcast signal from geostationary earth orbit (GEO) 1.

• Dementia and Neurocognitive Disorders
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• v.23 no.2
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• pp.95-106
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• 2024

Background and Purpose: Ventricle enlargement has been implicated in the pathophysiology of Alzheimer's disease (AD). We studied the relationship between ventricular size and cognitive function in patients with AD. We focused on the effect of the initial ventricle size on the rate of cognitive decline in patients with AD. Methods: A retrospective analysis of probable clinical AD participants with more than 2 magnetic resonance imaging images was performed. To measure ventricle size, we used visual rating scales of (1) Cardiovascular Health Study (CHS) score and (2) conventional linear measurement method. Results: Increased clinical dementia rating (CDR) was correlated with a decreased Mini-Mental Status Examination (MMSE) score, and increased medial temporal lobe atrophy (MTLA) and global ventricle size (p<0.001, p<0.001, p=0.021, respectively). There was a significant correlation between the change in cognitive function in the group (70%-100%ile) with a large initial ventricle size (p=0.021 for ∆CDR, p=0.01 for ∆MMSE), while the median ventricle size (30%-70%ile) showed correlation with other brain structural changes (MTLA, frontal atrophy [FA], and white matter) (p=0.036 for initial MTLA, p=0.034 for FA). Conclusions: In this study, the initial ventricle size may be a potential new imaging biomarker for initial cognitive function and clinical progression in AD. We found a relationship between the initial ventricle size and initial AD-related brain structural biomarkers.

• Dementia and Neurocognitive Disorders
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• v.21 no.2
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• pp.59-70
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• 2022

Background and Purpose: Neurofilament light chain (NfL) has been considered as a biomarker for neurodegenerative diseases including Alzheimer's disease (AD). We measured plasma NfL levels in older adults with cognitive complaints and evaluated their clinical usefulness in AD. Methods: Plasma levels of NfL, measured by using the single molecule array method, were acquired in a total of 113 subjects consisting of subjective cognitive decline (SCD; n=14), mild cognitive impairment (MCI; n=37), or dementia of Alzheimer type (DAT; n=62). Plasma NfL level was compared among three groups, and its association with cognitive and functional status was also analyzed. Results: After adjusting for age, plasma NfL level was higher in subjects with DAT (65.98±84.96 pg/mL), compared to in subjects with SCD (16.90±2.54 pg/mL) or MCI (25.53±10.42 pg/mL, p=0.004). NfL levels were correlated with scores of the mini-mental state examination (r=-0.242, p=0.021), clinical dementia rating (CDR) (r=0.291, p=0.005), or CDR-sum of boxes (r=0.276, p=0.008). Just for participants who performed amyloid positron emission tomography (PET), the levels were different between subjects with PET (-) (n=17, 25.95±13.25 pg/mL) and PET (+) (n=16, 63.65±81.90 pg/mL, p=0.010). Additionally, plasma NfL levels were different between vascular dementia and vascular MCI, and between Parkinson's disease- dementia and no dementia. Conclusions: This pilot study shows that in subjects with DAT, plasma NfL levels increase. Plasma NfL level correlated with cognitive and functional status. Further longitudinal studies may help to apply the plasma NfL levels to AD, as a potential biomarker for the diagnosis and predicting progression.

• Korean Journal of Psychosomatic Medicine
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• v.27 no.2
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• pp.155-163
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• 2019

Objectives : The aim of this study was to compare severity, neurocognitive functions, and behavioral and psychological symptoms of dementia (BPSD) according to the degree of temporal lobe atrophy (MTA) in Korean patients with dementia due to Alzheimer's disease and mild cognitive impairment due to Alzheimer's disease. Methods : Participants were 114 elderly subjects diagnosed with Alzheimer's disease or mild cognitive impairment in this cross-sectional study. MTA in brain MRI was rated with standardized visual rating scales (Scheltens scale) and the subjects were divided into two groups according to Scheltens scale. Severity was evaluated with Clinical Dementia Rating (CDR) and Global Deterioration Scale (GDS). Neurocognitive functions was evaluated with the Korean version of Short Blessed Test (SBT-K) and the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease assessment packet (CERAD-K). BPSD was evaluated with the Korean version of the Neuropsychiatric Inventory (K-NPI). Independent t-test was performed to compare severity, neurocognitive functions, and BPSD between two groups. Results : The group with high severity of MTA showed significantly lower scores in CDR, SBT-K, MMSE-KC, modified Boston naming test, word list recognition, and word list memory (p<0.05). There were no differences in K-NPI scores between two groups. Conclusions : Severity and neurocognitive functions of dementia had significant positive association with MTA, but BPSD had no association with MTA. Evaluating MTA seems to have potential benefit in diagnosing and treating neurocognitive impairments in the elderly. Further evaluation is needed to confirm the association between certain brain structures and BPSD.

• Journal of Korean Institute of Industrial Engineers
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• v.2 no.1
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• pp.93-100
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• 1976

Given a fixed production process and facility capacity, the ability to respond to market fluctuations in terms of changes in production, work force, and inventory is the major task of production management. The costs involved are primarily payroll (regular and overtime), inventory carrying, and hiring and firing. The magnitude of these costs is usually a significant portion of the operating costs of the firm and consequently a small percentage saving due to astute aggregate scheduling can mean substantial absolute saving. At least three demonstrably optimal techniques have been developed for solving this aggregate scheduling problem. These three optimal are apparently LDR, PPP, and SDR. By combining these three different approaches, another optimal solution was obtained by me. I call this CDR (Combined Decision Rule). This approach appears to be useful. This approach may be generalizable to aggregate scheduling involving a short term resources.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.365-368
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• 2007

Information institutes in the world provide users with collaborative digital reference service for answering users' questions. Korea Institute of Science and Technology Information has conducted Question포인트+ that is CDRS using global mechanism. KISTI has developed two types of global collaboration mechanism on CDRS: one is using Global Network, the other one is direct cooperation between KISTI and a German organization ZLB. This study analyzes the current global collaboration mechanism of CDRS at KISTI and suggests the future model of global collaboration mechanism to satisfy the users' needs.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1821-1828
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• 2010

In this study we suggest a method of optimization of verification hierarchy structure and system requirements management by using a verification matrix with traceability consideration. Verification items were gathered in the process of CDR(Critical Design Review), and analyzed with respect to requirements traceability structure. Missed or overlapped items were adjusted, and cross-correlated items between sub-systems were clustered and rearranged in order to structurize verification requrements (VRs). Those VRs are to be used as a guideline for the test and evaluation planning, development of test items and procedure, and system requirements management throughout the system integration stages.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.300-301
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• 2000

DVD는 CD사이즈의 광디스크에 고화질기 MPEG2 디지털 압축동화를 두 시간이상 수록할 수 있는 기록 및 재생기기로써 최초의 규격서가 1996년 8월에 발행되었다. 650nm의 적색반도체레이저와 개구수 0.6의 대물렌즈를 채용한 광픽업으로 직경 12cm의 단면디스크에 CD-ROM의 약 7배인 4.7GB에서 17GB까지의 용량저장이 가능하다. 변조방식은, DC성분을 억제할 수 있고, 또한 DR(Density Ratio)이 큰 EFM-Plus 변조를 채용하고, 에러정정방식은 32kB를 하나의 블록으로 하는 Reed Solomon Product code이다. File system은, 음성, 화상데이터와 컴퓨터 데이터를 통합할 수 있도록 계층구조로 하고, ISO9669 파일시스템과 UDF파일시스템을 함께 사용하고 있다. (중략)