치형수정에 의한 기어의 최적설계에 관한 연구

손유선(Yusun Son),황규석(Guesec Hwang),탁성훈(Seonghun Tak),류성기(Sungki Lyu) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

This study deals with the TE(Transmission Error) of gear tooth profile by modifying a profile and lead of a surface of tooth. First, we experimentally confirmed that the TE is a synthesis of the sliding velocity between both gears. Since various types of TE appear in the experiments, we introduced definition of transmission error and the optimism design by modifying a surface parameters. The test stand's performance is then evaluated through a series of multiple torque transmission error tests. Comparisons are made between data recorded before and after the test stand's redesign, and subsequently repeatability studies are performed to verify the veracity of the measured data. Finally, the experimental results are compared to the analytical predictions of two different gear analysis programs.

LDP를 이용한 기어의 전달오차 예측에 관한 연구

손유선(Yu-Sun Son),배효제(Hyo-Je Bae),탁성훈(Sung-Hoon Tak),장기(Qi Zhang),류성기(Sung-Ki Lyu) 한국기계가공학회 2008 한국기계가공학회 춘추계학술대회 논문집 Vol.2008 No.-

Predictin of Transmission Error was carried out by using LDP and compared with test results which was measured under no-load condition. Two different type of gear was used in this study, which has same macro-geometry and different micro-geometry. The magnitude of tip relief of gear set A was twice as much as that of gear set B. The Transmission error spectrum of each gear indicated the magnitude of first harmonic of gear set A was twice as much as that of gear set B and LDP Prediction also indicated same results. the comparison of LDP prediction and test results was almost same in 90% accuracy. Design loads of each gear were also found by using LDP and LDP calculated 115Nm for gear set A and 230Nm for gear set B.

키토산 / 알긴산 고분자 복합체로 된 봉합사

손유선(You Sun Son),양갑승(Kap Seung Yang),박상희(Sang Hee Park),권해용(Hae Yong Kweon),김수일(Su Il Kim),조종수(Chong Su Cho) 한국키틴키토산학회 2001 한국키틴키토산학회지 Vol.6 No.1

N/A Chitosan fiber spun through circular nozzle was immersed into alginate solution to enhance mechanical properties of the fiber for suture application. The tensile strength of the chitosan fiber increased with an increase of molecular weight and concentration of the chitosan. The dry tenacity of chitosan fiber (cps 15.7) was enhanced by treatment with alginate solution from 0.56 g/d to 1.71 g/d due to the formation of polymeric electrolyte complex between chitosan as polycation and alginate as polyanion. The optimum condition of treatment concentration and time of alginate to enhance mechanical properties of chitosan fiber was 0.5 wt% and 12 hrs, respectively. The morphology of the chitosan fiber after treatment with alginate showed smoother than that of chitosan fiber only.

초등학생 상담경험 실태와 학교적응도, 자기주도학습력 간의 관계

손유선(Yu-sun Son) 학습자중심교과교육학회 2022 학습자중심교과교육연구 Vol.22 No.22

목적 본 연구에서는 초등학생 상담경험 실태조사에서 초등학생의 상담경험과 상담경험 배경변인(상담 장소, 상담자 유형, 상담경험 지각)에 따른 학교적응도와 자기주도학습력의 차이 등을 확인하는 데 목적을 두었다. 방법 일반적인 상담경험 배경에 대한 실태조사 설문과 학교적응(조수정, 2014), 자기주도학습력(이경화, 김수연, 2018) 검사를 초등학생 3~6학년(208명)에게 실시하였고, 수집된 데이터를 사용하여 기술통계, 두 독립표본 t-test, ANOVA 방법으로 SPSS 25.0 프로그램을 통해 통계처리 하였다. 결과 첫째로 초등학생의 상담경험은 학교적응(학업태도와 규칙준수)과 관련이 있었고, 자기주도학습력과의 관련성은 없었다. 둘째로, 상담경험 배경 변인에 따른 학교적응도와 자기주도학습력의 일부 하위요인에서 차이가 있었다. 셋째로 학년에 따른 학교적응도에서의 차이를 나타냈고, 학교적응도와 자기주도학습력 간의 높은 상관을 보였다. 결론 본 연구를 통하여 초등학생의 상담경험과 학교적응, 자기주도학습력 간의 관계를 확인했으며 초등학생의 일반적인 학교 내외의 상담 가운데 특히 학교상담(교사, 학교상담실)은 초등학생의 학교적응과 자기주도학습력에 있어서 중요한 변인임을 알 수 있었다. 이에 본 연구는 초등학생 상담에 대한 학교현장과 관계자에게 일부 시사점을 제공한 것에 의의가 있다. Objectives In this study, the purpose of this study was to identify the difference between school adaptation and self-directed learning ability according to the background variables of counseling experience(counseling location, type of counselor, perception of counseling experience) and counseling experience in the relationship between the counseling experience, school adaptation, and self-directed learning ability of elementary school students. Methods A fact-finding survey on the background of general counseling experience, school adaptability (Jo Soo-jeong, 2014), and self-directed learning ability test (Lee Kyung-hwa, Kim Soo-yeon, 2018) were conducted on 3rd to 6th graders (208 students) of elementary school students. Descriptive statistics, two independent samples t-test, and ANOVA methods were used for SPSS 25.0 program statistical processing. Results First, the counseling experience of elementary school students was related to school adaptation (study attitude and rule observance), but was not related to self-directed learning ability. Second, there were differences in some sub-factors of school adaptation and self-directed learning ability according to the background variable of counseling experience. Third, there was a difference in school adaptation according to grade level, and there was a high correlation between school adaptation and self-directed learning ability. Conclusions Through this study, the relationship between the counseling experience of elementary school students, school adaptation, and self-directed learning ability was confirmed. In addition, it was found that school counseling (teacher, counseling room of school) is an important variable in elementary school students' school adjustment and self-directed learning ability among the general counseling inside and outside school. Therefore, this study is meaningful in that it provided some implications to the school field and related parties regarding counseling for elementary school students.

펨토초 레이저를 이용한 초정밀 인공지지체 제작과 선 폭과 선 간격에 따른 셀 증식평가

손유선(Y. S. Sohn),김종영(J. Y. Kim),조동우(D.-W. Cho) 한국정밀공학회 2010 한국정밀공학회 학술발표대회 논문집 Vol.2010 No.11월

고속회전용 기어의 전달오차 예측 및 측정에 관한 연구

손유선(Yusun Son),배효제(Hyoje Bae),탁성훈(Sunghoon Tak),장기(Qi Zhang),류성기(Sungki Lyu) Korean Society for Precision Engineering 2008 한국정밀공학회지 Vol.25 No.12

3차원 인공지지체 패턴이 갖는 세포 평가 특성에 따른 이중 공극 인공지지체의 개발

손유선 ( You Sun Sohn ),정진우 ( Jin Woo Jung ),김종영 ( Jong Young Kim ),조동우 ( Dong Woo Cho ) 한국조직공학과 재생의학회 2011 조직공학과 재생의학 Vol.8 No.2s

Scaffold, one of three essential elements of tissue regeneration, provides a proper environment for cells to grow in vitro and in vivo by playing that supporting role. Recent many research groups have fabricated scaffolds by various SFF (solid free-from fabrication) technologies that permit the control of internal/external geometry such as pore size, porosity, and line pattern of scaffold with reproducibility. To investigate the effect of scaffold pattern on cell behavior, tests were planned by the design of experiments (DOE) technique. Line width and line pitch were selected as controllable factor for cell adhesion and cell proliferation. Various kinds of patterned scaffolds with diverse line widths and pitches were fabricated by NSTL (nano stereolithography) system with high resolution. These scaffolds were seeded with MC3T3-E1, pre-osteoblast cell line, and were cultured in vitro for 7 days. To examine the effect of cell adhesion and proliferation on the scaffold patterns, CCK-8 assay was performed to quantify the living cell into each scaffold. Additionally, we fabricated and evaluated 3D bi-pore scaffold by NSTL system to investigate the effect of bi-pore structure in cell behavior. To realize this goal, we also fabricated the scaffold with only global pore and compared the effectiveness of two types scaffold in cell adhesion and proliferation. With these results, we confirmed that the scaffold patterns, such as line width and line pitch, can affect cell behavior and demonstrated that bi-pore scaffold had better cell adhesion and proliferation than scaffold with only global pore.

뇌성마비 환아 한의치료 기술에 대한 전문가 설문 및 심층 면접 연구

손지형,윤영주,유선애,Son, Chi Hyoung,Yun, Young Ju,Yu, Sun Ae 대한한방소아과학회 2016 대한한방소아과학회지 Vol.30 No.4

Objectives This study aims to investigate current status of the Korean medicine treatment on the cerebral palsy (CP) via interviewing the doctors who have expertise in CP children. Methods From June 2015 to May 2016, the surveys and in-depth interviews were conducted on the fifteen Korean medicine doctors. Results Based on the surveys and interviews, widely-used treatments were body acupuncture and herbal decoction. Scalp acupuncture, intradermal acupuncture and manipulation were also used frequently. Experts stated Korean medicine could be more effective in younger patients, patients with cognitive or language problem. They also stated that Korean medicine has its advantage on strengthening the body to help grow and develop in CP children. However, the absence of guideline related to Korean medicine treatment in CP children as well as high cost are the problems. Finally, the issues regarding Korean medicine treatment in CP children, based on the in-depth interviews, emerged when western medicine is used simultaneously, when having seizure during treatment. Further research is needed for better understanding. Conclusions This study provided current status of the evidence-based Korean medicine treatment in CP children. However, further studies about the addressed issues are needed.

모르핀이 신경아세포종 SH-SY5Y 세포에서 Peroxynitrite에 의한 세포고사를 막는것은 수용체 활성화에 의한 것이 아니다

손용,윤재승,최유선,김태요,안진영,송윤강,정영표 대한마취과학회 2000 Korean Journal of Anesthesiology Vol.39 No.2

Background: In the present study, we examined the effect of morphine on NO- and peroxynitriteinduced cell death using a human neuroblastoma SH-SYSY cell line which abundantly expresses μ, δ and κ-opioid receptors. Methods: The cultured cells were pretreated with morphine (100 μM) and exposed to 3-morpholino- sydnonimine (SIN-I, ImM). Agarose gel electrophoresis of DNA was done with the extracts from SH-SYSY cells. The cells were treated with selective ligands for opioid receptor subtypes and with PI3-kinase inhibitors. Cell damage was assessed by using an MTT assay. Spectrophotometric absorption spectra were measured from the mixture of morphine (100 μM) plus peroxynitrite (I mM) at room temperature. Results: SIN-1 treated cells showed the occurrence of a specific form of chromosomal DNA fragmentation which pretreatment with morphine inhibited. We selective ligands for opioid receptor subtypes, [D-Ala^2, N-Me-Phe^4, Gly-ol5]enkephalin (DAMGO, μ-opioid receptor agonist), [D-Pen] enkephalin (DPDPE, δ-opitor agonist) and U-69593 ( κ-opioid receptor agonist) at a con- centration of 10 pM did not prevent the cell death induced by SIN-1. Naloxone (20 μM) hardly antagonized the effect of morphine in SIN-1-induced cell death. The PI3-kinase inhibitors Wortmannin and LY294002 did not inhibit the action of morphine on apoptotic cell death. In the measurements of spectrophotometric absorption spectra, the peak of the absorbance of the mixture of morphine plus peroxynitrite at 295 - 300 nm disappeared three minutes after mixing. Conclusions: The present study showed that morphine protected the human neuroblastoma cell line, SH-SY5Y, from peroxynitrite-induced apoptotic cell death. However, it is suggested that the protective action of morphine is not via the activation of opioid receptors and/or the PI3-kinase pathway but possibly via direct chemical reaction.

기관내 삽관시 Verapamil 과 Esmolol 의 혼합투여가 혈압 및 심박수에 미치는 영향

손용,윤재승,김경일,김태요,정영표,최유선 대한마취과학회 2000 Korean Journal of Anesthesiology Vol.38 No.5

Background : Antihypertensive agents such as verapamil and esmolol are well known for their effects of hemodynamic stabilization on tracheal intubation. However, our previous study, Verapamil and esmolol did not attenuate heart rate and blood pressure. The aim of the present study was to evaluate the efficacy of combined administration of these drugs for controlling hemodynamic responses to tracheal intubation. Methods : Forty-eight patients, ASA physical status I or II, were randomly assigned to one of four groups (n = 12 each): normal saline (control), verapamil 0,1 mg/kg, esrnolol 1 mg/kg, and verapamil 0.05 mg/kg mixed with esmolol 0.5 mg/kg, Anesthesia was induced with thiopental 5 mg/kg intra- venously, and then saline, verapamil, esmalol or the mixed drugs were administered as an intravenous bolus, and immediately followed by succinylcholine 1.5 mg/kg. Tracheal intubation was performed 90 s after intravenous injection of experimental drugs. Systolic and diastolic blood pressure and heart rate were measured before induction and every minute for 5 minutes after tracheal intubation. Results : There was a significant attenuation in systolic bload pressure after tracheal intubation in the verapamil and mixed groups compared to the control and esmolol groups. Heart rates were signi- ficantly lower in the esmolol and mixed groups than in the verapamil groups after tracheal intubation. Conealusions : Combined administration of Verapamil 0.05 mg/kg with esmolol 0.5 mg/kg attenuated increases in blood pressure and heart rate after tracheal intubation. (Korean J Anesthesiol 2000; 38: 795~799)