Development of mouse over-expressing hOPN in podocytes within kidney glomeruli for evaluating renal toxicity

Boyun Choi,A Young Jung,Seung Hee Lee,So-Hye Hong,Jun-young Yang,Jin Hee Lee,Hyun-Kyung Kim,Ji Hyun Seok,Jong Kwon Lee 한국실험동물학회 2019 한국실험동물학회 학술발표대회 논문집 Vol.2019 No.1

20 대 멘탈 헬스를 위한 AI 그림일기 미술치료 앱 서비스 제안, "마치"

강보윤(Boyun Kang),김소정(Sojung Kim),소민경(Minkyoung So),최기은(Keeeun Choi),최준호(Junho Choi) 한국HCI학회 2020 한국HCI학회 학술대회 Vol.2020 No.2

최근 청년 세대에는 우울감을 겪거나 자신의 감정에 대해 무뎌지면서 더욱 자신의 감정을 말로 표현하는 것에 어려움을 느끼고 있다. 이를 위해 특히, 20 대를 위한 멘탈 헬스 어플을 제안한다. 마치 서비스는 말로 표현하기 어려운 자신의 감정을 그림으로써 더욱 쉽고 흥미로운 방식으로 감정 표현을 유도하고자 한다. 미술치료의 기법 중 가장 대중적으로 접근 가능한 그림 일기방식을 차용하여 서비스에 녹이고자 한다. 이에 대한 세부적인 기획을 위해 전문가 인터뷰와 사용자에게 유저 다이어리, 심층 인터뷰를 진행하였다. 이를 통한 기획 및 컨셉 도출 후, AI 챗봇 캐릭터의 퍼소나를 설정하고, 시나리오를 바탕으로 프로토타입을 제작하였다. 최종적으로 사용성 평가를 진행하여 기획한 컨셉에 대한 확인 과정을 거쳤다. 본 연구는 기존 멘탈 헬스 케어 앱의 텍스트 인터랙션 방식이 아닌 그림을 통한 새로운 인터랙션 방식을 제안한다는 점에 의의가 있다.

공유가치창출(CSV)전략이 반영된 시각장애인을 위한 제품 디자인 사례분석

최보윤(Choi, Boyun),구유리(Koo, Yoori) 한국디자인학회 2017 한국디자인학회 학술발표대회 논문집 Vol.2016 No.10

Effects of mirror polishing brick surface on process yield of multi-wire slicing for thin single-crystalline silicon solar cells

Choi, Sunho,Jang, Boyun,Kim, Joonsoo,Song, Heeun,Baek, Taehyeon,Han, Moonhee Elsevier 2015 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.122 No.-

<P><B>Abstract</B></P> <P>Thin silicon (Si) wafers with thickness of 100–140μm were obtained by using a multi-wire slicing process with a SiC slurry. We investigated the process yields of wafer slicing as well as physical/electrical properties of the sliced wafers with various thicknesses. As the wafer thickness decreases, the process yield abruptly decreased due to wafer breakage during the slicing process, and conventional polishing the brick surface was not enough to gain a considerable process yield. However, elimination of defects on the brick surface by mirror polishing resulted in an 83.1% enhancement of yield even for wafers with a thickness of 100μm. The number of wafers obtained was even higher than that of conventional 180μm-thick wafers (479 vs. 415 wafers in this research). Investigation of the microstructure of brick surfaces revealed that surface defects on bricks were main parameter to determine the yield of slicing process. Surface defects containing the micro-cracks introduced residual stress, which decreased the slicing process yield especially for thinner wafers. From measurements of physical and electrical properties, it was revealed that the relative total thickness variations (TTVs) and bowings increased and the characteristic fracture strength of sliced wafer and conversion efficiencies decreased as the wafer thickness decreased. For the wafer with thickness of 100μm, the relative TTV and bowing were 14.1% and 22.5mm, respectively. The conversion efficiency of a solar cell using this wafer was 17.6%, while that of a conventional Si solar cell using a 180μm-thick wafer was 18.4%.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Thin silicon wafers with thickness of 100–140μm were sliced by multi-wire slicing. </LI> <LI> Physical and electrical properties of thin Si wafers were investigated. </LI> <LI> Subsurface defects of the brick surface critically determined process yield in slicing Si wafers. </LI> </UL> </P>

마이봄샘 기능부전을 동반한 안구건조증 환자에 대한 펄스광선 치료의 임상효과

김보윤(Boyun Kim),권형구(Hyunggoo Kwon),최아영(Ayoung Choi),김주혜(Juhye Kim),전소희(Sohee Jeon) 대한안과학회 2021 대한안과학회지 Vol.62 No.3

목적: 마이봄샘 기능부전을 포함한 안구건조증 환자를 대상으로 펄스광선 치료(intense pulsed light;IPL)를 시행한 후 안구건조증에 대한 임상적 분석을 통해 치료 효과를 알아보고자 하였다. 대상과 방법: 마이봄샘 기능부전으로 진단된 환자 62명 124안을 대상으로 후향적 연구를 시행하였다. 대상 환자는 3주 간격으로 3차례의 IPL을 치료받았으며;치료 전과 3주 간격의 시간에 따른 Meibomian gland expressibility (MGE);Meibomian gland secretion score (MGS);눈물띠검사(TMH);비침습적 눈물막파괴시간(noninvasive break-time;NIBUT);플루오레신 각막염색 점수(Oxford scale);환자의 증상(Ocular Surface Diseases Index [OSDI];주관적인 증상 개선 정도)를 비교하였다. 결과: IPL 치료 후 마이봄샘 기능관련 지표(MGE;MGS);안구 표면 관련 지표(NIBUT;Oxford scale);안구건조 증상(OSDI score;주관적인 증상 개선 정도)은 치료 전과 비교하여 IPL 1차 후;IPL 3차 후 통계적으로 유의하게 개선되었다(모두 p<0.05). 하지만 눈물띠검사는 IPL 치료 전후 비교에서 통계적으로 유의한 변화를 보이지 않았다. 결론: 마이봄샘 기능부전을 가진 안구건조증 환자에게 IPL 치료는 눈물막을 안정시키고;마이봄샘 기능 이상 및 주관적인 증상을 개선시키므로 안구건조증의 효과적인 치료가 될 수 있음을 확인하였다. Purpose: To evaluate the therapeutic effect of intense pulsed light (IPL) therapy for the treatment of dry eye with meibomian gland dysfunction (MGD). Methods: A retrospective study was conducted for 124 eyes of 62 patients with dry eye with MGD who underwent 3 IPL sessions at 3 week intervals. All patients underwent clinical examination before and during treatment as well as 3 weeks after the last treatment. Measured parameters include Meibomian gland expressibility (MGE);Meibomian gland secretion (MGS) score;tear meniscus height (TMH);noninvasive break-time (NIBUT);corneal staining score (Oxford scale);Ocular Surface Diseases Index (OSDI);and subjective ocular discomfort improvement. Results: Meibomian gland function (MGE;MGS);ocular surface parameters (NIBUT;Oxford scale) and dry eye symptom (OSDI;subjective ocular discomfort improvement) of patients were significantly improved from baseline to after the 1st IPL;and the 3rd IPL weeks (p < 0.05 for all). However;no significant difference in TMH was observed. Conclusions: This study showed that IPL was a useful and effective treatment in patients of dry eye with MGD to stabilizes the tear film and improve meibomian gland function and ocular symptoms.

Formation of SiO_x shell on Si nanoparticles and its effects on electrochemical properties as a Li-ion battery's anode

Jang, Boyun,Koo, Jeongboon,Choi, Sunho,Kim, Joonsoo Elsevier 2018 Materials chemistry and physics Vol.215 No.-

<P><B>Abstract</B></P> <P>Crystalline Si core–amorphous SiO<SUB>x</SUB> shell nanoparticles were synthesized from SiCl<SUB>4</SUB> using an atmospheric microwave plasma process and their microstructures were investigated. It was found that the amorphous SiO<SUB>x</SUB> shell thickness was determined by varying the applied microwave power. The increase of applied power directly increased the length of the flame at the end of the plasma. Through observation of the microstructures with varying lengths of the flame, it was found that a highly crystalline Si phase was formed in the plasma and amorphous SiO<SUB>x</SUB> phase was formed in the flame. The longer flame resulted in the thicker SiO<SUB>x</SUB> shell around the Si core. The electrochemical properties of the varying SiO<SUB>x</SUB> shell thicknesses were also investigated in that the synthesized Si-SiO<SUB>x</SUB> nanoparticles were used as anode materials in a lithium-ion battery (LIB). Thin shells such as native oxide did not influence the electrochemical behaviour of the Si core, whilst some shells were too thick to allow Li-ions to react with the Si core. Using Si-SiO<SUB>x</SUB> nanoparticles with the optimum SiO<SUB>x</SUB>:Si ratio of 18:82, the following electrochemical properties were obtained: a first reversible capacity of 932 mAh/g, an initial columbic efficiency (ICE) of 52.5%, and a capacity retention of 83.7% at the 100<SUP>th</SUP> cycle.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Si nanoparticles with amorphous SiO<SUB>x</SUB> shells with various thicknesses are synthesized. </LI> <LI> The formation of SiO<SUB>x</SUB> shell and its effect on the Si nanoparticle is studied. </LI> <LI> The Si/SiO<SUB>x</SUB> ratios are varied by controlling flame length at the end of plasma. </LI> <LI> The relations between microstructures and electrochemical properties are analyzed. </LI> <LI> The Si-SiO<SUB>x</SUB> core-shell nanoparticle exhibits improved electrochemical performance. </LI> </UL> </P>

상사의 비인격적 감독이 이직의도에 미치는 영향: 정서적 스트레스와 직무열의의 이중매개효과

최보윤,정승철,Choi, Boyun,Jung, Sungcheol 한국디지털정책학회 2022 디지털융복합연구 Vol.20 No.4

본 논문은 조직에서 상사의 비인격적 감독이 이직의도에 미치는 영향을 확인하고 그 경로에서 정서적 스트레스와 직무열의의 매개효과를 검증하고자 하였다. 이를 위해 직장인 317명을 대상으로 온라인 설문조사를 실시하였으며 SPSS Macro 및 Bootstrapping 분석을 실시하였다. 연구 결과 비인격적 감독, 정서적 스트레스, 직무열의, 이직의도 간의 상관관계는 통계적으로 유의한 것을 확인하였으며 이중매개관계가 통계적으로 유의한 것을 확인하였다. 본 연구에서는 상사의 비인격적 감독과 정서적 스트레스, 직무열의, 이직의도에 대한 경로를 규명하였다는 점에서 시사점을 제공한다. 향후 종단적 연구 및 경로에 영향을 미치는 요인들에 대한 심층 연구가 필요할 것으로 보인다. This study was to verify the effect of the supervisor's abusive supervision on turnover intention and the mediating role of emotional stress and work engagement in the process. The online survey was conducted on 317 employees and the data were analyzed through SPSS Macro and bootstrapping. The results are as follows: the correlation between abusive supervision, emotional stress, work engagement and turnover intention was confirmed to be statistically significant, and dual mediating effect of emotional stress and work engagement was statistically significant. This study showed meaningful results on the path of the abusive supervision and turnover intention. Further studies with longitudinal method and in-depth studies on factors influencing pathways will be needed to verify substantially the dual mediating effect.

Control Variables of Remote Joint Analysis Realization on the M2M Case

( Sungryel Lim ),( Boyun Choi ),( Hongchul Lee ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.1

New trend called ubiquitous leads the recent business by standardization and integration. It should be the main issue how to guarantee the integration and accountability on each business, especially in mission critical system which is mainly supported by M2M (Machine to Machine) control mechanism. This study is from the analysis of digital forensics case study that is from the M2M Sensing Control Mechanism problem of the “Imjin River” case in 2009, where a group of family is swept away to death by water due to M2M control error. The ubiquitous surroundings bring the changes in the field of criminal investigation to real time controls such as M2M systems. The needs of digital forensics on M2M control are increasing on every crime scene but we suffer from the lack of control metrics to get this done efficiently. The court asks for more accurately analyzed results accounting high quality product development design. Investigators in the crime scene need real-time analysis against the crime caused by poor quality of mission critical systems. It seems to be every need of Real-Time-Enterprise, so called ubiquitous society on the case. We try to find the efficiency and productivity in discovering non-functional design defects in M2M convergence products focusing on three metrics in study model with quick implementation. Digital forensics system in present status depends on know-how of each investigator and is hard to expect professional analysis on every field. This study set up a hypothesis "Co-working of professional investigators on each field will qualify Performance and Integrity" especially in mission critical system such as M2M and suggests "Online co-work analysis model" to efficiently detect and prevent mission critical errors in advance. At the conclusion, this study proved the statistical research that was surveyed by digital forensics specialists around M2M crime scene cases with quick implementation of dash board.

금속 질화물 박막의 원자층 증착 및 반도체 분야 응용 연구 동향

이자영(Jayeong Lee),최보윤(Boyun Choi),안준혁(Junhyeok Ahn),전나리(Nari Jeon) 한국세라믹학회 2024 세라미스트 Vol.27 No.1

With the recent advances in nanotechnology and the semiconductor industry, the study of nitride thin films has become increasingly important in the fields of electronic devices, optical devices, and nanomaterials research. Various methods have been used to synthesize nitride thin films, among which ALD stands out as a deposition technique capable of yielding high-quality thin films at lower temperatures via sequential self-limiting surface treatments. As the need for high-quality thin film deposition at the nanoscale and highly conformal thin films has emerged, the deposition of metal nitride thin films by ALD has been actively researched, encompassing hafnium nitride, aluminum nitride, titanium nitride, zirconium nitride, and silicon nitride. In this review, we will discuss the current landscape of research pertaining to metal nitride thin films prepared by ALD.

Thiol-reducing agents prevent sulforaphane-induced growth inhibition in ovarian cancer cells

Kim, Seung Cheol,Choi, Boyun,Kwon, Youngjoo TaylorFrancis 2017 Food & nutrition research Vol.61 No.1

<P><B>ABSTRACT</B></P><P>The inhibitory potential of sulforaphane against cancer has been suggested for different types of cancer, including ovarian cancer. We examined whether this effect is mediated by mitogen-activated protein kinase (MAPK) and reactive oxygen species (ROS), important signaling molecules related to cell survival and proliferation, in ovarian cancer cells. Sulforaphane at a concentration of 10 μM effectively inhibited the growth of cancer cells. Use of specific inhibitors revealed that activation of MAPK pathways by sulforaphane is unlikely to mediate sulforaphane-induced growth inhibition. Sulforaphane did not generate significant levels of intracellular ROS. Pretreatment with thiol reducers, but not ROS scavengers, prevented sulforaphane-induced growth inhibition. Furthermore, diamide, a thiol-oxidizing agent, enhanced both growth inhibition and cell death induced by sulforaphane, suggesting that the effect of sulforaphane on cell growth may be related to oxidation of protein thiols or change in cellular redox status. Our data indicate that supplementation with thiol-reducing agents should be avoided when sulforaphane is used to treat cancer.</P>