Miscellaneous chromonychia

( Hyunsun Park ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.2

Up-to-date of emerging treatment of alopecia areata

( Hyunsun Park ) 대한피부과학회 2021 대한피부과학회 학술발표대회집 Vol.73 No.-

Up-to-date of emerging treatment of alopecia areata

( Hyunsun Park ) 대한피부과학회 2021 대한피부과학회 학술발표대회집 Vol.73 No.1

Hair disease, microbiome, and probiotics

( Hyunsun Park ) 대한피부과학회 2021 대한피부과학회 학술발표대회집 Vol.73 No.1

Hair disease, microbiome, and probiotics

( Hyunsun Park ) 대한피부과학회 2021 대한피부과학회 학술발표대회집 Vol.73 No.-

Do Successful Jacks Make a Successful Team? Members’ Functional Experience and Team Performance

Hyunsun Park(박현선),Hyuntak Roh(노현탁) 연세대학교 경영연구소 2021 연세경영연구 Vol.58 No.2

본 연구는 팀 구성원의 경력(직무경험) 특성이 팀 성과에 미치는 영향력을 살펴보는 것을 주요한 목적으로 한다. 팀을 구성하는 개별 구성원들의 경험특성이 집단 성과에 갖는 영향력에 대한 논의는 그동안 학계 및 기업 현장에서 오랜 관심의 대상이었음에도 불구하고, 관련 이론적 논의 및 실증적 검증은 아직 충분히 이루어지지 않았다. 본 연구는 이러한 문제의식에 대한 나름의 해답 및 실증적 근거를 제시하기 위하여, 먼저 팀 구성원의 직무경험 다양성(경험의 범위, 넓이)이 팀 성과에 미치는 영향력을 비선형적 관계(역 U자 형태)로 설정하고 이를 실증적으로 검증하고자 하였다. 또한 본 연구에서는 개인의 경험특성으로 경험의 넓이(다양성) 뿐 아니라 경험의 질(성공경험)을 함께 고려하여, 직무경험 다양성과 팀 성과 간 비선형적 관계가 경험의 질에 의해 어떻게 조절되는지에 대한 이론적, 실증적 검증 역시 수행하였다. 실증검증을 위해 2015년 미국 할리우드에서 개봉한 장편영화 200편과 해당 작업을 수행한 주연배우의 경력 데이터를 수집하여 이를 분석에 활용하였다. 분석 결과, 본 연구의 가설에서 제안한 바와 같이, 팀 구성원의 경험다양성과 팀 성과 간 역U자 형태의 비선형 관계가 존재함을 확인하였다. 또한 이러한 비선형 관계는 팀 구성원의 성공경험 수준이 높을 때 더 명확하게 나타나는 것을 확인할 수 있었다. Applying the new conceptualization of intrapersonal functional diversity, this study explores the link between team’s functional breadth (i.e., team members’ aggregate breadth of functional experience) and team performance. Considering that team members’ aggregate functional breadth brings cognitive and motivational advantages as well as cognitive and relational difficulties, we predicted a curvilinear relationship that is contingent on the level of aggregate functional breadth. We further examined the interaction effects between team members’ aggregate breadth and success of functional experience on team performance. Our hypotheses were tested in the setting of Hollywood feature film industry using a large-scale, lifetime functional experience dataset of 897 main cast actors and actresses who participated in 200 films released in the year of 2015. Our analyses revealed that there indeed exists an inverted U-shaped relationship between main cast members’ aggregate job breadth and box office revenue. Consistent with our expectation, the main effect relationship was moderated by main cast members’ aggregate job success, such that the inverted U-shape became more apparent under a high level of aggregate job success.

Deep Learning-Enabled Detection of Pneumoperitoneum in Supine and Erect Abdominal Radiography: Modeling Using Transfer Learning and Semi-Supervised Learning

Park Sangjoon,Ye Jong Chul,Lee Eun Sun,Cho Gyeongme,Yoon Jin Woo,Choi Joo Hyeok,Joo Ijin,Lee Yoon Jin 대한영상의학회 2023 Korean Journal of Radiology Vol.24 No.6

Objective: Detection of pneumoperitoneum using abdominal radiography, particularly in the supine position, is often challenging. This study aimed to develop and externally validate a deep learning model for the detection of pneumoperitoneum using supine and erect abdominal radiography. Materials and Methods: A model that can utilize “pneumoperitoneum” and “non-pneumoperitoneum” classes was developed through knowledge distillation. To train the proposed model with limited training data and weak labels, it was trained using a recently proposed semi-supervised learning method called distillation for self-supervised and self-train learning (DISTL), which leverages the Vision Transformer. The proposed model was first pre-trained with chest radiographs to utilize common knowledge between modalities, fine-tuned, and self-trained on labeled and unlabeled abdominal radiographs. The proposed model was trained using data from supine and erect abdominal radiographs. In total, 191212 chest radiographs (CheXpert data) were used for pre-training, and 5518 labeled and 16671 unlabeled abdominal radiographs were used for fine-tuning and self-supervised learning, respectively. The proposed model was internally validated on 389 abdominal radiographs and externally validated on 475 and 798 abdominal radiographs from the two institutions. We evaluated the performance in diagnosing pneumoperitoneum using the area under the receiver operating characteristic curve (AUC) and compared it with that of radiologists. Results: In the internal validation, the proposed model had an AUC, sensitivity, and specificity of 0.881, 85.4%, and 73.3% and 0.968, 91.1, and 95.0 for supine and erect positions, respectively. In the external validation at the two institutions, the AUCs were 0.835 and 0.852 for the supine position and 0.909 and 0.944 for the erect position. In the reader study, the readers’ performances improved with the assistance of the proposed model. Conclusion: The proposed model trained with the DISTL method can accurately detect pneumoperitoneum on abdominal radiography in both the supine and erect positions.

Efficient generation of conditional mutant mice by CRISPR RNP electroporation and AAV donor infection

Hyunsun Park,Hye-Ryun Kim,Haengseok Song 한국실험동물학회 2021 한국실험동물학회 학술발표대회 논문집 Vol.2021 No.7

Objective: CRISPR/Cpf1 is versatile genome editing tool for studying the functions of genetic elements. Electroporation (EP)-based CRISPR technologies offer significant advantages over microinjection since it can be used for a large-scale manipulation in a short period of time and delivers a variety of molecules to zygotes. Adeno-associated virus (AAV) has been recently used as a trans-zona pellucida delivery vector of DNA donor for EP-based CRISPR system. In this study, we applied CRISPR/AsCpf1 ribonucleoprotein (RNP) EP with AAV to generate knock-in mice that had an Elk-3 conditional allele. Materials and Methods: RNP was electroporated into zygotes that were infected with AAV containing a conditional allele of Elk-3 gene which serves as a long DNA donor. Electroporated zygotes were cultured in vitro to the blastocyst stage for evaluating recombination efficiency of homology-directed repair or transferred at the two-cell stage to pseudopregnant mice to obtain live pups. Integration of loxP site(s) was determined by RFLP analyses, digestion with restriction enzyme(s), and/or Sanger sequencing. Results: Transduction efficiency of AAV1 and AAV6 serotypes was compared using AAV-CMV-GFP in pre-implantation embryos. The fluorescence intensity was much higher in AAV1 than in AAV6 and AAV-Elk-3 was then generated using AAV1. When introns 1 and 2 of the Elk-3 gene was targeted in zygotes that were infected with AAV1-Elk-3, most zygotes (39/40, 97.5%) became two-cell, and 74.3% (29/39) of the two-cell embryos developed into the blastocysts. PCR genotyping for loxP sites showed that 37.9% (11/29) of the blastocysts had loxP sites in introns 1 and 2. A Cre recombination assay validated that 4 of 11 blastocysts (36.3%) and 2 of 5 live pups (40%) contained two loxP sites in the same allele. Collectively, this study provides that RNP EP with AAV infection is a fast and efficient method to generate mice with conditional alleles. This work was supported by grants from the (NRF) (NRF- 2019R1A6A1A03032888) and (NRF-2020R1A2C2005012).

A Multistep Tag Comparison Method for a Low-Power L2 Cache

Hyunsun Park,Sungjoo Yoo,Sunggu Lee IEEE 2012 IEEE transactions on computer-aided design of inte Vol.31 No.4

<P>Tag comparison in a highly associative cache consumes a significant portion of the cache energy. Existing methods for tag comparison reduction are based on predicting either cache hits or cache misses. In this paper, we present novel ideas for both cache hit and miss predictions. We present a partial tag-enhanced Bloom filter to improve the accuracy of the cache miss prediction method and hot/cold checks that control data liveness to reduce the tag comparisons of the cache hit prediction method. We also combine both methods so that their order of application can be dynamically adjusted to adapt to changing cache access behavior, which further reduces tag comparisons. To overcome the common limitation of multistep tag comparison methods, we propose a method that reduces tag comparisons while meeting the given performance bound. Experimental results showed that the proposed method reduces the energy consumption of tag comparison by an average of 88.40%, which translates to an average reduction of 35.34% (40.19% with low-power data access) in the total energy consumption of the L2 cache and a further reduction of 8.86% (10.07% with low-power data access) when compared with existing methods.</P>

What you need to know about ingrown toenails

( Hyunsun Park ) 대한피부과학회 2020 대한피부과학회 학술발표대회집 Vol.72 No.1