중량물 운반시 잡기유형에 따른 근전도 분석

이훈식,강영택,윤양진,정미라,유국종,서국웅,김정태 釜山大學校 附設 體育科學硏究所 1999 體育科學硏究所 論文集 Vol.15 No.-

The purpose of this study was to examine EMG changes of the body according to method the holding during carrying object. The experiments were conducted with utilizing EMG analyses for five male and five female adults as subjects. The results were as followed. 1. The higher muscle action potential of vertical holding was shown than that of right holding when carrying objects in MMH work in proportion to the weight of the object. The came from the subjects using their brachial muscles much to maintain the angles of their wrist joints and elbow joints for keeping their stable postures while walking. 2. The higher muscle action potential of right holding was shown in right and left elector-muscles of their spines(L1-L2, L4-L5) while carrying in all stages of weights except 25kg objects than that of vertical holding. These results were caused from more use of brachial muscles than elector-muscles of spines in carrying weight objects. So vertical holding is more effective in carrying weight objects at a short distance than right holding.

차아염소산나트륨 처리와 멸균법이 근관 치료용 파일의 부식에 미치는 영향에 관한 연구

양원경,라윤식,이영규,손호현,김미리 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.2

근관 치료시 많이 사용되고 있는 K-flex S-S 파일 (Maillefer, USA)과 Profile Ni-Ti 파일 (Maillefer, USA), K-3 Ni-Ti파일 (SybronEndo, USA)의 부식 정도를 보기 위하여 총 360개의 20번 file을 1) 멸균소독 방법 (고압가열멸균소독, E-O gas 소독) ,2) 근관세척 액 (5.25% 차아염소산나트륨, 생리식염수) ,3) 멸균소독 횟수 (1, 5, 10회 ) 에 따라 36개 실험군으로 나누었다. 각각의 파일을 각 군별로 처리한 뒤, 세 명의 검사자가 광학 현미경 하에서 25배의 배율로 검사하여 0; 부식 없음, 1; 경도의 부식, 2; 중등도의 부식, 3; 심한 부식으로 점수화 하였다. 심한 부식을 보이는 파일의 표면은 SEM으로 관찰하였고 Kruskal-Wallis test (p < 0.05)를 이용하여 통계 분석 처리하여 차아염소산나트륨 접촉 여부와 멸균소독 방법의 차이에 의한 부식 정도를 평가하였다. 그 결과 고압가열멸균소독을 10회 시행한 파일은 통계적으로 유의한 차이를 보여 부식 정도가 심하였고, 1회나 5회 고압가열멸균소독을 시행한 파일과 E-O 가스로 소독한 파일들은 부식의 정도가 경미하여 통계적으로 유의하지 않았다. 차아염소산나트륨 접촉 여부와 제조사 혹은 파일 재료에 따른 유의성 있는 차이는 없었다 A variety files made of stainless steel (S-S) or nickel-titanium (Ni-Ti) are used during endodontic treatment. The purpose of tt)is study was to evaluate the corrosion susceptibility of S-S and Ni-Ti endodontic files. Three brands of files were used for this study: K-flex S-S files (Maillefer, USA), Profile Ni-Ti files (Maillefer, USA), K-3 Ni-Ti files (SybronEndo. USA). 120 files of each brands (21mm, ISO size #20) were divided into 12 groups according to 1) sterilization methods using Autoclave or Ethylene Oxide (E-O) gas, 2) Irrigation solutions using 5.25% NaOCl or Saline, 3) the number of sterilization (1, 5, 10 times), After above procedures, each of the files was inspected by three examiners with a light microscope and camera at X25. Each file was judged and ranked according to the following criteria: 0;, no corrosion, 1; mild corrosion, 2; moderate corrosion, and 3; severe corrosion. The files of high score were examined under the Scanning Electron Microscope. Data were statistically analyzed with the Kruskal-Wallis test (p < 0.05). Most of the ten time-autoclaved files had showed mild to moderate corrosion. But, one or five time-autoclaved files did not show corrosive surface. NaOCl treatment and E-O gas sterilization did not influence on corrosion. There was a significant difference in corrosion susceptibility between sterilization methods and the number of autoclaving. However, there was no significant difference between brands and file materials.

테니스 포핸드시 밀어치기와 때려치기 타법의 운동학적 분석

윤양진,정미라,서국웅,이훈식,황명숙,강영택,윤길환 釜山大學校 附設 體育科學硏究所 1999 體育科學硏究所 論文集 Vol.15 No.-

This study consists in clarifying the meaning of various angles and velocity, and two types of the stroke of a pushing shot and hitting shot through the three-dimensional image analyses among the factors of exercise. To attain the purpose of such studies, the result of experiment and analysis for each of three athletes of boys and girls in high school and three persons in general came to the conclusion as follows; 1. The last motion of a group of A having a command of a follow shot showed greatly, compared with two groups of B and C, and this showed that a group of A took a rectilinear motion greatly to gain power and two group of B and C took a rotary motion greatly to gain speed. 2. A group of A having a command of a pushing shot move body weight forward from behind and give the first consideration to a rectilinear motion, and two groups of B and C having a command of the stroke of hitting shot used the turning of the shoulder and the waist and gave much weight to a rotary motion than a rectilinear one. 3. The position of the hitting point of a group of A having a command of a pushing shot turned out to be the waist, and that of the hitting point of two groups of B and C, the chest, and namely this showed that the position of the hitting point was decided according to the form of the stroke and pictures of various kinds. 4. In impacting, the speed decreased, for the power was controled to keep an accurate timing of stroke just before impacting

인조 합성 테니스 바닥재의 지면 반력 분석

조승제,정미라,서국웅,박승범,윤양진,이훈식,강영택 釜山大學校 附設 體育科學硏究所 1998 體育科學硏究所 論文集 Vol.14 No.-

Some authors suggest that certain types of surfaces are the origin of such injuries. A few years after the first medical concerns about surfaces were voiced, publications of biomechanical measurements apperared, describing accleration, force, and impact measurement on different types of surfaces. In many sport activities, surfaces can be under very high dynamic load. This was the reason for the development of various methods for impact simulation, like the development of various methods for impact simulation, like the artificial athlete. Furthermore, it is important to collect information about the hardness of new and already existing surfaces in sport arenas. The idea on which this measuring system is based Is as follows: The stiffness of the material can be computed from the kinematics measurd at touch down of a rigid body onto a material sample. The results show the following The result for the artifical surfaces(Synpave ace) is surprising. It is known that these surfaces are much harder than synpave rebound classic, synpave spring. This finding suggests that it may be possible that the subjective impression is used as one criterion in the selection of landing(or style) strategies. The number of subjects in this experiment is too small to make statistically significant conclusions. It is shown analytically that when an object a deformable surface, the acceleration it experiences is inversely propotional to its mass. In future, it need to stress that the interaction between shoe and surface is important, and this aspect has now become well accepted. Considering biomechanical aspect in player's injury, it request Korean Standards for synthetic playing surfaces in sport like ASTM(America Society for Testing & Materials) standards of America, DIN 18035 standards of Germany, BSI standards of U.K.

임팩트시 테니스 라켓 재질의 차이에 따른 근전도 분석

윤양진,유국종,서국웅,정미라,강영택,이훈식,서국은 釜山大學校 附設 體育科學硏究所 1999 體育科學硏究所 論文集 Vol.15 No.-

The purpose of this paper is to select 7 male athletes and female athletes of high school, and to compare their active potential differences of upper arm muscles according to characteristic of a racket. the results obtained are as follows: 1. According to the accumulative distribution rate of racket material, graphite and wood material show better efficiency in case of brachio radialis muscle of male athletes, but the racket material shows no constant efficiency in brachii radialis muscle of female athletes. In case of flexor carpi radialis muscle, wood material provides better efficiency only for male athletes. In case of triceps brachii muscle, wood material gives better efficiency to males athletes and steel material gives better efficiency to females athletes. Especially in case of biceps brachii muscle, neither male nor female athletes are influenced by racket materials at impact. 2. In the muscle load rate according to racket material, wood has the highest muscle active potential and graphite has the lowest active potential. Therefore, graphite is thoght to be better in the efficiency of muscle load rate.

Remote preparation of three-photon entangled states via single-photon measurement

Ra, Young-Sik,Lim, Hyang-Tag,Kim, Yoon-Ho American Physical Society 2016 Physical Review A Vol.94 No.4

<P>Remote state preparation (RSP) provides an indirect way of transferring quantum information based on the nonlocal effect of quantum measurement. Although RSP has been demonstrated in recent years to remotely prepare multiphoton states, quantum measurement on the same number of additional photons was required, i.e., to prepare N-photon states via RSP, quantum measurement on the other N-photons was required, hence significantly limiting practicality and applicability of RSP. Here we report an experimental demonstration of remote preparation of three-photon entangled states by measuring only a single-photon entangled with the three photons. We further generalize our protocol to prepare multiphoton entangled states with arbitrary photon number and purity and to prepare a genuinely three-partite entangled state, both via single-photon measurement. As our RSP scheme relies on the nonlinearity induced by single-photon measurement, it enables quantum state engineering of multiphoton entangled states beyond the linear optical limit. Our results are expected to have significant impacts on quantum metrology and quantum information processing.</P>

Reversed interplay of quantum interference and which-way information in multiphoton entangled states

Ra, Young-Sik,Tichy, Malte C.,Lim, Hyang-Tag,Gneiting, Clemens,Mølmer, Klaus,Buchleitner, Andreas,Kim, Yoon-Ho American Physical Society 2017 Physical review. A Vol.96 No.2

<P>We report experimental studies of quantum interference of multiphoton states impinging on a two-port balanced beam splitter. When the distinguishability between the two input paths is increased, we observe a reduction followed by a resurgence of the interference visibility in multiphoton coincidence detection. We ascribe this unusual behavior to the competition among contributions from distinct number state components of the interfering fields. Our results suggest that wave-particle duality gives rise to a wide range of largely unexplored phenomena in multiparticle interference.</P>

Phase and amplitude controlled heralding of N00N states

Ra, Young-Sik,Lim, Hyang-Tag,Oh, Joo-Eon,Kim, Yoon-Ho The Optical Society 2015 Optics express Vol.23 No.24

Inappropriate Gonadotropin Secretion in Polycystic Ovary Syndrome: The Relationship with Clinical, Hormonal and Metabolic Characteristics

( A Ra Shim ),( Yu Im Hwang ),( Kyung Jin Lim ),( Young Mi Choi ),( Young Eun Jeon ),( Seok Kyo Seo ),( Si Hyun Cho ),( Young Sik Choi ),( Byung Seok Lee ) 대한산부인과학회 2011 Obstetrics & Gynecology Science Vol.54 No.11

Objective To evaluate the clinical, hormonal and metabolic characteristics according to luteinizing hormone (LH)/follicle stimulating hormone (FSH) ratio in women with polycystic ovary syndrome (PCOS). Methods A total of 225 women with PCOS were included in this study. They were divided into two groups according to LH/FSH ratio; group A (LH/FSH < 2, n=160) and group B (LH/FSH > 2, n=65). We compared clinical, hormonal and metabolic characteristics including age at menarche, body mass index (BMI), blood pressures, ovarian volume, and serum androgen levels between the two groups. Serum glucose and insulin levels, fasting glucose/insulin ratio, homeostatic model assessment of insulin resistance (HOMA-IR), and lipid profi les were also compared between the two groups. Pearson correlation coeffi cients were used to evaluate correlation between the LH/FSH ratio and various parameters. Results Age of menarche in the group B was signifi cantly later than that in the group A. BMI, waist-hip ratio and blood pressures were signifi cantly lower in the group B compared to those of the group A. Ovarian volume and serum levels of LH, estradiol, total testosterone, sex-hormone binding globulin, 17-hydroxyprogesterone (OHP), and high density lipoprotein were signifi cantly higher in the group B. Postprandial 2 hours glucose, insulin and HOMA-IR were signifi cantly higher in the group A. After adjustment of BMI, the LH/FSH ratio was signifi cantly positively correlated with age at menarche, ovarian volume, total testosterone levels, and 17-OHP levels. Conclusion The inappropriate gonadotropin secretion may be negatively correlated with BMI, and positively with age of menarche and increased ovarian androgen production irrespective of BMI in women with PCOS. However, it may not be associated with metabolic characteristics.

양자역학의 실험적 검증에 관해

라영식(Young-Sik RA),김윤호(Yoon-Ho KIM) 한국물리학회 2022 물리학과 첨단기술 Vol.31 No.12

In 1935, Einstein, Podolsky, and Rosen (EPR) argued that (then new) quantum mechanics was incomplete. At the heart of EPR’s paradox was the strange non-local nature of an entangled state which allowed EPR to simultaneously assign local values for position and momentum of a particle. In 1964, John Bell proposed an inequality (Bell’s inequality) that must be satisfied by any local realistic theory. The experimental confirmation of quantum physics, i.e., the experimental test of Bell’s inequality, required a pair of particles in an entangled state. The experiments first performed in the early 1970s, followed by a series of experiments until now, have confirmed the violation of Bell’s inequality, strongly implying that local realistic descriptions of nature are not consistent with experimental observations. The early simplistic view of entanglement has now been significantly expanded to include mixed states and multiple particles. Moreover, theoretical and experimental studies on the nature of entanglement have led to quantum information science where entanglement is an essential resource. In this article, we briefly review the early experiments on Bell’s inequality and experimental attempts to close “loopholes” as well as some key experiments on quantum information.