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Park, Hyeree,Lee, Joonhyuk,Park, Sung-Hong,Choi, Seung Hong The Korean Society of Radiology 2019 KOREAN JOURNAL OF RADIOLOGY Vol.20 No.2
<P><B>Objective</B></P><P>Alternate ascending/descending directional navigation (ALADDIN) is a novel arterial spin labeling technique that does not require a separate spin preparation pulse. We sought to compare the normalized cerebral blood flow (nCBF) values obtained by ALADDIN and dynamic susceptibility contrast (DSC) perfusion magnetic resonance imaging (MRI) in patients with primary brain tumors.</P><P><B>Materials and Methods</B></P><P>Sixteen patients with primary brain tumors underwent MRI scans including contrast-enhanced T1-weighted imaging, DSC perfusion MRI, and ALADDIN. The nCBF values of normal gray matter (GM) and tumor areas were measured by both DSC perfusion MRI and ALADDIN, which were compared by the Wilcoxon signed rank test. Subgroup analyses according to pathology were performed with the Wilcoxon signed rank test.</P><P><B>Results</B></P><P>Higher mean nCBF values of GM regions in the bilateral frontal lobe, temporal lobe, and caudate were detected by ALADDIN than by DSC perfusion MRI (<I>p</I> <0.05). In terms of the mean or median nCBF values and the mean of the top 10% nCBF values from tumors, DSC perfusion MRI and ALADDIN did not statistically significantly differ either overall or in each tumor group.</P><P><B>Conclusion</B></P><P>ALADDIN tended to detect higher nCBF values in normal GM, as well as higher perfusion portions of primary brain tumors, than did DSC perfusion MRI. We believe that the high perfusion signal on ALADDIN can be beneficial in lesion detection and characterization.</P>
An Overview of the Korean Longitudinal Study on Health and Aging
JoonHyuk Park,Soo Lim,JaeYoung Lim,KwangIl Kim,MoonKu Han,InYoung Yoon,JongMin Kim,YoonSeok Chang,ChongBum Chang,HoJun Chin,EunAe Choi,SeokBum Lee,YoungJoo Park,NamJong Paik,TaeKyun Kim,Hak C. Jang,Ki 대한신경정신의학회 2007 PSYCHIATRY INVESTIGATION Vol.4 No.2
Objective-The Korean Longitudinal Study on Health and Aging (KLoSHA) was developed 1) to estimate the prevalence, incidence and progression of common geriatric diseases; 2) to determine the risk factors for common geriatric diseases and to develop preventive strategies by managing potentially modifiable determinants; 3) to investigate the influence of common geriatric diseases on the quality of life and general health status; 4) to evaluate the levels of health and functional status of Korean elderly persons. Methods-The KLoSHA was designed as a population-based prospective cohort study on health, aging and common geriatric diseases of Korean elders aged 65 years and over. The baseline study of the KLoSHA was conducted from September 2005 through September 2006 in Seongnam. Follow-up studies will be performed at 4-year intervals without an endpoint. Results-At the baseline study, 992 subjects (714 randomly sampled elderly subjects aged 65 years or over, 278 volunteers aged 85 years or over) were enrolled and completed the study. Prevalences and risk factors of common geriatric disorders in Korean elders were estimated, and the normative data of neuropsychological measures, general health parameters, and laboratory tests were drawn. Conclusion-The KLoSHA may not only provide comprehensive epidemiological data on the health status and common geriatric disorders of Korean elders, but also may stimulate comprehensive multidisciplinary and interdisciplinary researches on aging and geriatric disorders and contribute to policy formulation and planning of health management programs and social services in Korea.
박준혁(Joonhyuk Park),고효인(Hyoin Koh),허현무(Hyunmoo Hur),유원희(Wonhee You),김남포(Nampo Kim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11
Unstable vibrations of railway vehicle wheels generate the curve squeal noise in tight curve. This squeal noise has to be reduced in order to increase the service quality of railway system by eliminating the main factors that make the wheel unstable. In this paper, main parameters which affect the stability of railway vehicle wheel are introduced and the stability analysis is carried out using those parameters in frequency domain. Time domain analysis is also performed. In the time domain analysis, using a conventional Korean subway vehicle model, transient time response of a wheel is analyzed when the vehicle is running in curved track. Finally, the results are compared and discussed.