Changes in the Clinical Characteristics of Kawasaki Disease After Coronavirus Disease (COVID-19) Pandemic: A Database Analysis

Kim Beom Joon,Choi Arum,Kim Hwan Soo,Oh Jin-Hee,Lee Jae-Young,Kim Sukil,Han Ji-Whan,Kim Kyunghoon,Kim Hyun Hee 대한의학회 2022 Journal of Korean medical science Vol.37 No.20

Background: The impact of the coronavirus disease 2019 (COVID-19) pandemic on Kawasaki disease (KD) has not yet been established. We investigated changes in the observed number and severity of KD cases and accompanying coronary artery complications during the COVID-19 pandemic in Korea. Methods: This retrospective observational study included patients aged < 18 years with acute-phase KD diagnosed between March 2018 and February 2021. Data were extracted from the Clinical Data Warehouse that houses data from five affiliated university hospitals in Korea. We analyzed changes in the number of patient admissions and clinical characteristics, including cardiac complications, before and after the onset of the COVID-19 pandemic. Results: A total of 475 admissions were included in the analysis. After March 2020, we observed a significant decrease of 33% in the number of hospitalizations for KD compared with the average number of hospitalizations during the previous 2 years. The number of admissions per month significantly decreased by 7.9 persons/month (95% confidence interval, −13.8 to −2.0; P < 0.05) compared with that before COVID-19. By contrast, the proportion of patients aged < 1 year with KD increased. The proportion of patients with refractory KD and the rate of cardiac complications did not change significantly. Conclusion: Since the onset of the COVID-19 pandemic, the total number of hospital admissions for KD has decreased in Korea. Although the proportion of admissions of infants aged < 1 year increased, no changes were observed in clinical courses and complications.

Prevalence, incidence and birth rate of endometriosis in Korea using big data

( Oyoung Kim ),( Suhyun Shim ),( Youngsin Han ),( Hye Jin Hwang ),( Youn-jee Chung ),( Hyun-hee Cho ),( Mee-ran Kim ),( Mira Kim ),( Chai-young Jung ),( Kyung-hee Chae ),( Sukil Kim ) 대한산부인과학회 2019 대한산부인과학회 학술대회 Vol.105 No.-

Objective: The aim of this study is to estimate the prevalence, incidence and birth rate of endometriosis in Korea using big data. Methods: This study is using administrative data provided by the Korean National Health Insurance Service (NHIS). These data from overall Korean population, totaling 45 million people, with national claims data for the period from January 1, 2002, to December 31, 2016. We selected patients with endometriosis as primary or secondary diagnosis code from the NHIS database and estimated prevalence and incidence rate and birth rate of endometriosis according to time and age group. Results: 433,422 women were diagnosed as endometriosis from January 1, 2002 to December 31, 2016. The overall prevalence of endometriosis is 2.7 per 1000 women. The prevalence increased gradually except a few periods, especially from 2007 to 2008. The estimated incidence is 1.4 per 1000 women. It also increase gradually, especially in the last five years. 39658 patients out of 211884 gave birth after diagnosis. The peak age was 29 in this group. A one year difference between the time of diagnosis and the time of birth was most common. On the other hand, for those who were treated before giving a birth, 2 years of time difference was most common. Among patients who gave birth, 56% of them gave birth without treatment. Conclusion: The prevalence and incidence of endometriosis in Korean women were lower than previous reports in high-risk populations studies. We found a significant trend of increase in diagnosing endometriosis in Korean women with time, especially in young age group.

Temperature Dependence of the Photocurrent in Ge1−xSnx Layers

Sukill Kang,Yeon-Ho Kil,Tae Soo Jeong,Chel-Jong Choi,Kyu-Hwan Shim,Dae-Jung Kim,Yong-Dae Choi,Taek Sung Kim 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.2

The temperature dependence of the photocurrent in Ge1−xSnx layers was measured for different Sn compositions (0.00 x 0.83%). As the Sn composition in the Ge1−xSnx layer increased, the photocurrent peak was clearly red shifted in comparison with that of Ge. As the measurement temperature was increased, the photocurrent peak was also clearly red shifted. The measured temperature dependence of the energy band gap was nicely fitted by using Varshni’s empirical expression. Temperature-dependent bowing parameters were fitted for the equation relationship.

Raman Spectroscopy and Photocurrent of GaAsN/GaAs Multiple Quantum Wells

Hyeoncheol Kim,Kyu-Hwan Shim,Tae Soo Jeong,Sukill Kang,Taek Sung Kim 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.2

The Raman and photocurrent of the GaAsN/GaAs multiple quantum wells (MQWs) was studied. The Raman spectra areobserved to be dominated by the GaAs longitudinal optical (LO) phonon mode as the strongest peaks show up around287–292 cm -1 . Moreover, the weak and broad spectral features in the range of 265–270 cm -1 originate from the peaks associatedwith the GaAs transverse optical (TO) phonon mode. And, the peaks observed in the photoluminescence and thephotocurrent spectra were preliminarily assigned to electron–heavy hole (e 1 –hh) and electron–light hole (e 1 –lh) fundamentaltransitions. Two additional transitions related to MQWs region are observed other than transitions involving the ground state. The structural properties of GaAsN/GaAs MQWs were investigated by using high-resolution X-ray diff raction (HRXRD).

다중 루프의 비 대칭 할당을 통한 병렬 처리

김석일(Sukil Kim) 한국정보과학회 1990 한국정보과학회 학술발표논문집 Vol.17 No.2

다중루프의 병렬처리 기법은 가용한 프로세서의 수를 몇개의 그룹으로 나누고 각각의 그룹이 다중 루프의 각 루프별로 병렬처리하는 방법이다. 기존의 대칭형 루프병렬화 기법은 다중루프의 중첩루프의 레벨에 따라 프로세서를 몇개의 그룹으로 나누고 각 그룹의 프로세서를 내측루프(inner loop)의 병렬처리에 이용하는 방안이다. 그러나 역방향 자료종속관계(backward data-dependence relation) 내에 루프 블럭이 존재하는 다중루프는 대칭형 루프병렬화 기법을 적용해도 최적의 결과를 얻을 수 없다. 본 논문에서는 이러한 루프의 경우에 사용될 수 있는 비대칭형 루프병렬화 기법을 제안하고 시뮬레이션을 통하여 그 효과를 입증하였다.

Temperature dependence of the photocurrent in Ge1−x Sn x layers

Kang, Sukill,Kil, Yeon-Ho,Jeong, Tae Soo,Choi, Chel-Jong,Shim, Kyu-Hwan,Kim, Dae-Jung,Choi, Yong-Dae,Kim, Taek Sung 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.

<P>The temperature dependence of the photocurrent in Ge1-x Sn (x) layers was measured for different Sn compositions (0.00 a parts per thousand currency sign x a parts per thousand currency sign 0.83%). As the Sn composition in the Ge1-x Sn (x) layer increased, the photocurrent peak was clearly red shifted in comparison with that of Ge. As the measurement temperature was increased, the photocurrent peak was also clearly red shifted. The measured temperature dependence of the energy band gap was nicely fitted by using Varshni's empirical expression. Temperature-dependent bowing parameters were fitted for the equation relationship.</P>

Estimation of Supply and Demand for Cardiologists in Korea

Mira Kim,Kyunghee Chae,Ju Mee Wang,Arum Choi,Jang-Whan Bae,Keon-Woong Moon,Sukil Kim 대한심장학회 2024 Korean Circulation Journal Vol.54 No.1

Background and Objectives: The objective of this study was to estimate the supply and demand for cardiologists in Korea and provide evidence for healthcare policy to ensure a stable and adequate workforce for optimal cardiovascular disease management. Methods: Past trends of inflow and outflow of cardiologists were used to make crude projections, which were then adjusted based on demands of services to obtain final projections. Inflow of cardiologists was estimated using second-order polynomial regression and demand for cardiology care was estimated using linear regression. Results: There were 1,139 active cardiologists who were under the age of 65 in clinical practice in Korea. The estimated number of cardiologists from 2022 to 2040 showed that the number of cardiologists would peak at 1,344 in 2032 and gradually decrease thereafter. We also estimated an increase of 947,811 cases of heart-related procedures annually from 2023 to 2032. The number of heart-related procedures per cardiologist would increase 1.4 times from 12,964 in 2023 to 17,862 in 2032. The estimated number of emergency patients per cardiologist under 50 years old would almost double from 544 in 2022 to 987 in 2032. Conclusions: We expect significant shortage of cardiologists in Korea within the next 10 years. The number of emergency patients per cardiologist will increase by nearly 50%, leading to high individual workload for cardiologists. To prevent this imbalance between supply and demand, an organized and collective approach by the specialty of cardiology is imperative to produce a balanced workforce.

이층구조인 클러스터 하이퍼큐브 네트웍의 설계

김석일(Sukil Kim) 한국정보과학회 1994 정보과학회논문지 Vol.21 No.12

본 논문에서는 TCHM(m, p)로 명명된 이층구조의 클러스터 하이퍼큐브를 설계하고 이를 분석하였다. 여기서 TCHM(m, p)는 통신프로세서마다 m개의 통신 포트를 가지고 있으며 연산프로세서와의 연결에 사용되는 포트의 수가 p개이며, 나머지 (m-p)개의 포트는 CP들을 (m-p) 차원 하이퍼큐브를 구성하는 데 사용된다. 표현할 수 있는 네트웍 위상이 star 네트웍인 TCHM(m, m)으로부터 기존의 하이퍼큐브인 TCHM(m, 1)에 이르기까지 다양한 TCHM(m, p) 중에서 TCHM(m, 2)는 시스템을 구성하는 AP의 수가 최대이나 시스템 구성비용이 최소인 비용 최적 시스템이다. 본 논문에서는 TCHM(m, 2)의 특징을 연구하였으며, 적용할 수 있는 통신 알고리즘도 제안하였다. 또한 TCHM(m, 2)의 평균경로길이가 (m-1)차원 하이퍼큐브의 평균경로길이에 비하여 짧음을 확인하였다. This paper designs and analyzes two-level clustered hypercube multiprocessor networks, which we call TCHM(m, p), where m denotes the number of ports of each communication processor (CP), and p is the number of ports interconnecting p application processors (APs) to a CP. Thus, m-p ports are used to connect CPs to construct an m-p dimensional hypercube. Among the wide spectrum of TCHM(m, p) network topologies, from a star, TCHM(m, m) to an ordinary hypercube, TCHM(m, 1), TCHM(m, 2) is an cost optimal topology among TCHM(m, p)s, such that TCHM(m, 2) minimizes the system cost while maximizing the number of APs in the system. 1n this paper, we explore properties of the network and propose a communication algorithm for the system. We also conclude that the average distance on TCHM(m, 2) is less than that on an (m-l) dimensional hypercube.

PALM 시스템의 병렬 라이브러리 설계 및 시스템의 통신과 연산 성능 평가

김석일(Sukil Kim),이영성(Young-Sung Lee) 한국정보과학회 1992 한국정보과학회 학술발표논문집 Vol.19 No.1

PALM시스템은 두개의 연산 프로세서를 버스로 연결하여 하나의 클러스터로 구성하고 각각의 클러스터를 하이퍼큐브 네트웍으로 연결하여 시스템내의 통신을 이중으로 하는 계층구조의 클러스터 컴퓨터로 충북대학교 병렬처리 및 프로그램언어 연구실에서 개발중이다. 본 연구에서는 PALM에 적합한 시스템 프로그램과 병렬처리를 지원하는 루틴을 설계하고 이를 PALM/286 test-bed에서 구현하였으며 시스템에서의 통신과 연산에 관한 성능평가를 수행하였다. 실험결과 PALM/286은 밀결합 다중 프로세서 시스템의 성능을 지니는-메세지 패싱에 의한 프로세서간 통신이 이루어지는-소결합 다중 프로세서 시스템임이 밝혀졌다. 아울러 본 논문에서 제안한 시스템 루틴과 병렬처리 라이브러리의 정확성도 확인되었다.

분산메모리형 다중프로세서 시스템에서 다행관측행렬의 병렬 Downdating기법

김석일(Sukil Kim),이충한(Chung-Han Lee) 한국정보과학회 1995 정보과학회논문지 : 시스템 및 이론 Vol.22 No.12

This paper introduces a new parallel HUGD (Householder Updating and Givens Downdating) algorithm, that would shorten the overall computation-time complexity compared with that of the existing parallel GCFD algorithm. The parallel HUGD algorithm consists of two stages; the first stage is to produce a Cholesky factor of a multiple-row observation matrix by a parallel QR-factorization procedure; the second stage is to downdate the Cholesky factor through the parallel GCFD. Since the parallel GCFD of the second stage performs Columnwise parallel operations, the parallel QR-factorization of the first stage also performs columnwise parallel Householder reflections Such an alignment between two stages would eliminate a parallel transpose of the Cholesky factor, and thus, the overall computation time complexity of the parallel HUGD can be lesser than that of the parallel GCFD. As the proposed algorithm requires recursive message broadcasting, the algorithm can be applicable on distributed memory multiprocessor systems that equip broadcasting features. 본 논문에서는 기존의 병렬 GCFD(Givens Cholesky Factor Downdating)기법과 비교하여 시간복잡도가 개선된 병렬 HUGD(Householder Updating and Givens Downdating)기법을 제안하였다. 병렬 HUGD기법은 다행관측행렬을 병렬 QR-분할을 이용하여 상삼각행렬로 변환하고 계산된 상삼각행렬을 기존의 병렬 GCFD(Givens Cholesky Factor Downdating)로 downdating하는 두 가지 단계로 구성되어 있다. 특히, 제안된 기법의 두 번째 단계에서 수행하는 GCFD기법이 열 단위로 병렬처리하는 특성을 지니고 있으므로 첫 번째 단계에서도 열 단위의 QR-분할이 가능한 병렬 Householder updating을 이용하였다. 그 이유는 첫 번째 단계와 두 번째 단계 사이에서 발생하는 관측행렬의 병렬 전치(parallel transpose) 작업을 배제하여 통신비용을 줄일 수 있으며 이를 통하여 전체적으로 시간복잡도를 개선할 수 있기 때문이다. 제안된 기법은 반복적인 메시지 방송을 위주로 하는 통신 특성을 지니는 알고리즘이므로 메시지 방송이 가능한 구조와 분산메모리형 다중 프로세서 시스템에 적합하다.