Feasibility of Pediatric Low-Dose Facial CT Reconstructed with Filtered Back Projection Using Adequate Kernels

Hye Ji,유선경,이정은,So Mi Lee,Hyun-Hae Cho,Joon Young Ohm 대한영상의학회 2022 대한영상의학회지 Vol.83 No.3

Purpose To evaluate the feasibility of pediatric low-dose facial CT reconstructed with filtered back projection (FBP) using adequate kernels. Materials and Methods We retrospectively reviewed the clinical and imaging data of children aged < 10 years who underwent facial CT at our emergency department. The patients were divided into two groups: low-dose CT (LDCT; Group A, n = 73) with a fixed 80-kVp tube potential and automatic tube current modulation (ATCM) and standard-dose CT (SDCT; Group B, n = 40) with a fixed 120-kVp tube potential and ATCM. All images were reconstructed with FBP using bone and soft tissue kernels in Group A and only bone kernel in Group B. The groups were compared in terms of image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Two radiologists subjectively scored the overall image quality of bony and soft tissue structures. The CT dose index volume and dose-length product were recorded. Results Image noise was higher in Group A than in Group B in bone kernel images (p < 0.001). Group A using a soft tissue kernel showed the highest SNR and CNR for all soft tissue structures (all p < 0.001). In the qualitative analysis of bony structures, Group A scores were found to be similar to or higher than Group B scores on comparing bone kernel images. In the qualitative analysis of soft tissue structures, there was no significant difference between Group A using a soft tissue kernel and Group B using a bone kernel with a soft tissue window setting (p > 0.05). Group A showed a 76.9% reduction in radiation dose compared to Group B (3.2 ± 0.2 mGy vs. 13.9 ± 1.5 mGy; p < 0.001). Conclusion The addition of a soft tissue kernel image to conventional CT reconstructed with FBP enables the use of pediatric low-dose facial CT protocol while maintaining image quality.

단어 형성 기제로서의 유추에 대한 재고찰 -유추의 유형 분류를 중심으로-

김혜지 ( Kim¸ Hye-ji ) 국어학회 2021 국어학 Vol.- No.99

본 연구는 단어 형성 기제인 유추에 대하여 살펴보는 것을 목적으로 한다. 어휘부에 존재하는 기존 단어에 기반하여 새로운 단어를 만드는 과정인 유추는 개별 단어 차원에서 이루어지거나 같은 형식을 공유하는 계열체로부터 형성된 틀을 통하여 실현될 수 있다. 본고는 유추의 유형을 개별 단어에 의한 유추, 틀에 의한 유추의 둘로 나누고, 개별 단어에 의한 유추는 유추 과정에서 모형 단어와 표적 간에 존재하는 유사성의 종류에 따라 다시 음운론적 유사성에 기반한 유추, 형태론적 유사성에 기반한 유추, 의미론적 유사성에 기반한 유추의 세 가지로 나누어 신어의 형성 과정에서 각 유형의 유추가 실현되는 양상을 살펴보았다. 한편 본고에서는 복합유추의 개념을 제안함으로써 유추 과정을 통하여 새로운 단어가 형성될 때에 각 유형의 유사성들이 개별적으로 작용할 수도 있으나 서로 다른 유사성이 결합되어 실현되기도 함을 확인하였다. The purpose of this paper is to examine the analogy, which is the mechanism for word formation. Analogy, the process of creating new words based on existing words in the lexicon, can be realized through similarities between individual words or through a schema formed from words that share the same form. In this paper, the type of analogy is divided into two: analogy by individual words and analogy via schema. In addition, we explore the aspects in which analogy by individual words are realized in the formation of new words by dividing them into three categories of similarities between model words and targets: analogies based on phonological similarity, analogies based on morphological similarity, and semantic similarity. In the meantime, this paper proposed the concept of combined analogy by confirming that each type of similarity may act individually when a new word is formed through the analogy process, but that three similarities may also appear in combination.

코로나19와 여가제약: 위계적 여가제약 모델 검증

사혜지 ( Sa¸ Hye Ji ),한지훈 ( Han¸ Jee Hoon ) 한국체육학회 2021 한국체육학회지 Vol.60 No.1

본 연구는 팬데믹 선언 이후 여가활동 참여 유형의 변화와 코로나19에 따른 여가제약에 주목하였다. 코로나19 발병에 따른 여가제약의 차이 변화를 살펴보고, 위계적 여가제약 이론을 통하여 여가제약 요인들이 어떻게 단계적으로 작용하는지 살펴보고 팬데믹 시대에 여가현상을 폭넓게 이해하는데 그 목적이 있다. 연구의 수행을 위해 설문지를 측정도구로 사용하였으며, 비확률 표집 방법 중 편의 추출법을 사용하여 총 317개의 자료를 수집한 후 분석하였다. 자료처리에서는 SPSS와 AMOS 프로그램을 사용하였다. 코로나 발병 전에는 신체적 활동, 사회적 활동, 자연적 활동, 문화적 활동, 지적활동의 순서로 나타났다. 하지만, 코로나 발병 이후에는 자연적 활동, 지적 활동, 신체적 활동, 사회적 활동, 문화적 활동의 순서로 나타났다. 둘째, 코로나19 발병에 따른 내재적, 대인적, 구조적 제약의 차이를 알아보기 위하여 전과 후로 나누어 분석한 결과 모두 통계적으로 유의한 차이가 나타났다. 마지막으로 코로나19 전과 후 모두 제약을 직면하는 순서는 내재적, 대인적, 구조적 순서로 나타났다. This study focused on the change in the type of leisure activity participation after the pandemic and the leisure constraints caused by COVID-19. Also, examine the differences in leisure constraints following the COVID-19 outbreak, and how the leisure constraint factors work step by step through the hierarchical leisure constraint theory in the pandemic era. To achieve the goal of the study, a total 317 questionnaires were collected from Korea. The collected data were analyzed and interpreted by SPSS and AMOS. Prior to the COVID-19 outbreak, physical activity, social activity, natural activity, cultural activity, and intellectual activity appeared in the order. However, after the COVID-19 outbreak, it appeared in the order of natural activity, intellectual activity, physical activity, social activity, and cultural activity. Second, in order to find out the difference between the intrapersonal, interpersonal, and structural constraints of the outbreak of COVID-19, the results of analysis by dividing into before and after showed statistically significant differences. Finally, the order of confronting constraints both before and after COVID-19 is in the order of intrapersonal, interpersonal, and structural.

Prevalence of Pediatric Autism Spectrum Disorder in Korea Using National Statistics Including the COVID-19 Pandemic, 2011 to 2021

Hyeji Eom(Hyeji Eom),Minji Kim(Minji Kim),Jung Kyung Yoo(Jung Kyung Yoo),Eunjoo Bae(Eunjoo Bae),Jeonghyeon Yi(Jeonghyeon Yi),Ji Young Lee(Ji Young Lee) 대한소아신경학회 2022 대한소아신경학회지 Vol.31 No.1

Purpose: Regularly analyzing the prevalence of autism spectrum disorder (ASD) is important to inform policies and strategies for proper management. The present study aimed to esti-mate trends in ASD prevalence according to age and time in Korean children. Methods: We monitored the annual prevalence of ASD in children aged 2 to 18 years based on information from Statistics Korea and the Korean National Health Insurance Service. We estimated changes in prevalence between 2011 and 2021 after stratifying partici-pants into three age groups. Furthermore, we analyzed the prevalence of ASD by birth year. Results: The highest level of prevalence appeared in children aged 6 years, and thereafter, it de-clined with age. The prevalence of ASD in children aged 2 to 18 years increased from 0.05% in 2011 to 0.12% in 2021. During the same time, the prevalence in preschool children (2 to 5 years) remarkably increased from 0.04% in 2011 to 0.12% in 2021, while the prevalence in adolescents (13 to 18 years) increased from 0.05% in 2011 to 0.09% in 2021. The prevalence of ASD notably increased during the coronavirus disease 2019 (COVID-19) pandemic (2020 to 2021). Among children born between 2011 and 2015, the prevalence of ASD was higher for children with recent birth years, especially during the COVID-19 pandemic. Conclusion: The overall ASD prevalence in children and adolescents in Korea seems to be increasing, especially in preschool children during the COVID-19 pandemic. Early and more effec-tive interventions are necessary for Korean children.

Low-complexity CRC-aided early stopping unit for parallel turbo decoder

Hyeji Kim,Youngjoo Lee,Ji-Hoon Kim IET 2015 Electronics letters Vol.51 No.21

<P>A low-complexity distributed cyclic redundancy check (CRC) architecture for the CRC-aided early stopping unit is proposed. In the previous distributed CRC unit, the general high-order Galois field (GF) multiplier occupies almost the area of the CRC unit and requires high-hardware cost and long critical path-delay. Accordingly, a computation algorithm based on GF arithmetic is analysed and an optimal CRC unit with the small order of the GF multiplier and newly designed linear feedback shift register is proposed. The proposed CRC architecture is implemented in 65 nm CMOS process for radix-2<SUP>2</SUP> and radix-2<SUP>4</SUP> parallel turbo decoders based on LTE-Advanced. In the radix-2<SUP>2</SUP> system, reductions of about 57.1% of gate count, 31.7% of critical path-delay and 44.1% of power consumption are achieved compared with the previous work.</P>

Obstacle Detection and Collision Estimation using Kalman Filter and CPA algorithm for UAV Autonomous Landing

Hyeji Kim,Cheonman Park,Dongjin Lee 제어로봇시스템학회 2020 제어로봇시스템학회 국제학술대회 논문집 Vol.2020 No.10

Effect of Insulin and Epidermal Growth Factor Treatment During In Vitro Growth Culture on Growth and Development of Pig Oocytes Derived From Small Antral Follicles

Hyeji Shin,Minji Kim,Ji Eun Park,Joohyeong Lee,Seung Tae Lee,Eunsong Lee 한국수정란이식학회 2018 한국수정란이식학회 학술대회 Vol.2018 No.11

This study was conducted to evaluate the effects of insulin and epidermal growth factor (EGF) in a in vitro growth (IVG) medium on oocyte growth, in vitro maturation (IVM) and embryonic development of pig oocytes derived from small antral follicles (SAF) less than 3 mm in diameter. SAF oocytes were cultured for 2 days to induce IVG in alpha-minimal essential medium supplemented with 1 mM dbcAMP and 15% (v/v) fetal bovine serum. After IVG culture, oocyte maturation was induced by culturing IVG oocytes in IVM medium for 44 h. IVM oocytes that extruded the first polar body were selected and induced for parthenogenesis (PA) by applying electric stimulus. SAF oocytes cultured under the insulin treatment showed a significantly increased (P < 0.05) nuclear maturation (73.8%) compared to those cultured with insulin and EGF (59.8%). After PA, the proportions of blastocysts based on the number of metaphase II oocytes were significantly higher (P < 0.05) in oocytes that were cultured for IVG with insulin, EGF, and insulin + EGF (32.4%, 35.2%, and 34.8%, respectively) than in control (22.9%). IVG oocytes treated with insulin showed an increased oocyte diameter (116.3 μm) compared to those treated with insulin and EGF (114.0 μm) (P < 0.05). Intra-oocyte GSH content significantly increased (1.07 pixels/oocyte) by insulin treatment during IVG compared to that of oocytes treated with insulin + EGF (0.78 pixels/oocyte). These results demonstrate that IVG culture of SAF oocytes under insulin or/and EGF treatment supports oocyte maturation and improves embryonic development to the blastocyst stage after PA in pigs.

A Two-level Decision Fusion Rule for Cooperative Sensing in Cognitive Radio Systems

Hyeji Kim(김혜지),Jun-pyo Hong(홍준표),Wan Choi(최완) 한국통신학회 2010 한국통신학회 학술대회논문집 Vol.2010 No.6

Investigating Research Trend of User Experience Based on a Literature Survey

Hyeji Jang,Sung H. Han,Jiyoung Kwahk,Dong Yeong Jeong,Joohwan Park,Mingyu Lee,Kyudong Park,Ju Hwan Kim,Dawoon Jeong 대한인간공학회 2017 대한인간공학회 학술대회논문집 Vol.2017 No.4

The aim of this study is to investigate research trend of user experience (UX) and find limitations of current researches. UX have obtained attention as one of the important trend in various fields. With the advent of the 4th industrial revolution, use behavior of product and service is changed. Although there is needs to consider and research this change in academia, it is not that mature yet. In order to systematically understand the research trend and find limitations of current researches, we collected literature published after 2000 from various fields. Total 347 literatures are collected. Collected literatures were analyzed from several perspectives such as definition of UX and research type. Based on the result, three limitations are drawn. There are two issues, target of interaction and scope of interaction, related to the definition of UX. UX researches have been conducted for several purposes such as UX occurrence principle and evaluation criteria. However, there are still some limitations of current researches. Among them, three limitations we suggest are in the following: First, it is limited to one-to-one relationship between user and product/service. Second, most researches are focused only on the direct interaction with product or service. Third, evaluation of UX mainly depends on the subjective criteria. The result of this study is expected to be helpful when researchers decide direction of future UX research.

An autopsy case of cerebral arterial thrombosis after vaccination with ChAdOx1 nCOV-19

Hyeji Yang,Jaeyoon Ha,Hyun Wook Kang 제주대학교 의과학연구소 2022 The Journal of Medicine and Life Science Vol.19 No.2

We present a fatal case of cerebral arterial thrombosis after corona virus disease 19 (COVID-19) vaccination with ChAdOx1 nCOV-19. The deceased was a 63-year-old woman with no relevant medical history. She presented symptoms of nausea, fatigue, and headache immediately after vaccination. Ten days after vaccination, she suddenly started vomiting and developed high blood pressure. The patient eventually died 23 days after vaccination. Autopsy findings showed that the cerebral arteries and internal carotid arteries were fully enlarged and were compacted with thrombi. The brain stem showed ischemic necrosis, and extravasation from this necrotic lesion led to focal subarachnoid hemorrhage around the brain stem where large blood clots still remained. No aneurysms or atherosclerotic changes were found in these arteries. We note the following three facts. Firstly, all symptoms occurred immediately after vaccination; secondly, the main cause of death was consistent with known side effects of the vaccine; and lastly, the mechanism of thrombus formation in this case goes beyond the general category of thrombogenesis known so far. While the authors know that this case does not fall into known categories of vaccine side effects, we presenting this case to demonstrate that a comprehensive review of various possibilities related to vaccine side effects is needed to establish a COVID-19 defense system.