• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.275-278
• /
• 2002

The recognition of the natural background radiation is important not only for radiological education but also for the promotion of people's scientific view about radiation. We made a "room" on the web showing natural background radiation as part of a VRM (Virtual Radiation Museum). The "room" shows the video images of the tracks of charged particles from natural background radiation, alpha and beta ray track from known sources using a Large Scale Diffusion Cloud Chamber. The purpose of this study is to make clear the origin of a kind of track (named A-track) which is thick and easy to recognize with the length less than several cm in the cloud chamber, and to make numerical explanation of its counting rate. The study was carried out using a Large Scale Diffusion Cloud Chamber (Phywe, Germany) installed in the Niigata Science Museum. The Model RNC (Pylon Electronics, Canada) was used as Rn-222 source. Ra-226 activity in RNC was 111.6 Bq calibrated with NIST protocol. Rn-222 gas was injected into the cloud chamber. Continuous video recording with use of Digital Handycam (SONY, Japan) was carried out for 360 min. after injection of Rn-222 gas. The number of alpha-ray track (alpha track) in the video images was analyzed. The growth and decay curve of the total activity of Rn-222 and its alpha emitting progeny were calculated and compared with the count of the alpha tracks. As a result the alpha tracks formed by Rn-222 injection resemble A-Tracks. The relationship between A-track in the cloud chamber and atmospheric Rn is discussed.

• Proceedings of the Optical Society of Korea Conference
• /
• 2007.07a
• /
• pp.223-224
• /
• 2007

광기록의 역사는 1980년대초 Sony와 Philips가 공동 개발한 CD (compact disc: 640MB)의 출현으로부터 시작하여 1996년의 DVD (digital versatile disc: 4.7GB)를 거쳐 최근의 BD (Blu-ray disc: >20GB)에까지 이르고 있다. Read-only memory, recordable, rewritable 등 다양한 저장 및 재생방식이 존재하는데, 이는 레이저 조사에 의한 기록매체의 특성변화의 가역성 (reversibility)에 의존하므로 저장 및 재생방식에 따라 저장매체 또한 다르게 된다. 기록용량의 증가는 레이저의 파장이 짧아지고 동시에 사용된 렌즈의 개구수 (NA: Numerical aperture)가 증가함에 따른 빔 spot size의 감소에 기인한다. 회절한계를 극복하여 빔의 spot size를 줄이고자 하는 연구는 현재도 전세계적으로 활발히 이루어지고 있고 이러한 노력의 일환으로 어느 정도의 추가적인 저장용량 증가는 가능할 수 있으나, 2차원 방식으로는 대용량 광정보기록 (수백 GB ${\sim}$ TB급)의 실현은 불가능하다는 것이 일반적인 예상이다. 한편 장기적으로 기존의 2차원 정보기록방식을 대체하고 저장용량을 획기적으로 증가시킬 수 있는 bit-type 3차원 광정보기록의 개념이 1990년을 전.후로 처음으로 제시되었다. 이는 2차원 bit 정보가 수십 내지 수백 개의 다층 (multi-layer) 형태로 기록되는 방식인데, 그동안 산업체의 관심이 상대적으로 높지 않았던 이유는 영화, 음악 등 엔터테인먼트 시장성 확대를 위해 Blu-ray disc나 HD-DVD에 대한 연구개발에 치중해왔기 때문이다. 하지만 최근 급변하는 정보시스템 서비스 환경 속에서 정보유통량이 기하급수적으로 증가하고 있고 개인이 취급하는 정보량도 2010년경에는 수백 GB 단위가 될 것으로 예상되고 있으며 디지털 방송, 네트워크를 기반으로 한 서비스 수요 뿐 만 아니라 전자도서관이나 VOD (Video on Demand) 서비스 사업에 필수적인 수 TB급의 대용량 저장장치에 대한 수요 또한 크게 증가할 것으로 전망된다. 이에 따라 점차 그 물리적 한계에 다다르고 있는 기존의2차원 정보저장방식을 대체하고 저장용량을 획기적으로 증가시킬 수 있는3차원 정보기록(> $10^{13}$ $bits/cm^3$)에 대한 필요성이 대두된다.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.12-12
• /
• 2017

Genetic improvement in potato can be carried out through several approaches, as sexual crosses, somatic hybridization, mutation and genetic engineering. Although the approach is different, but the goal is the same, to get a superior cultivar. Mutation and genetic engineering are very interesting methods for genetic improvement of potato plants. Mutation by gamma-ray irradiation have been performed to get some new potato cultivars which are more resistant to disease and have higher productivity. We have carried out a mutation of some potato cultivars and obtained some excellent clones to be potentially released as new superior cultivars. By the mutation method, we have released one potato cultivar for the French fries industry, and we registered one cultivar of potato for chips, and two cultivar for vegetable potatoes. Actually we are doing multi-location trial for three clones to be released as new cultivars. Through genetic engineering, several genes have been introduced into the potato plant, and we obtained several clones of transgenic potato plants. Transgenic potato plants containing FBPase gene encoding for fructose bisphosphatase, have a higher rate of photosynthesis and higher tuber productivity than non-transgenic plants. This result suggests that FBPase plays an important role in increasing the rate of photosynthesis and potato tuber productivity. Some transgenic potatoes containing the Hd3a gene are currently being evaluated for their productivity. Over expression of the Hd3a gene is expected to increase tuber productivity and induce flowering in potatoes. Transgenic potato plants containing MmPMA gene encoding for plasma membrane ATPse are more tolerant to low pH than non-transgenic plants, indicating that plasma membrane ATPase plays an important role in the potato plant tolerance to low pH stress. Transgenic potato plants containing c-lysozyme genes, are highly tolerant of bacterial wilt diseases caused by Ralstonia solanacearum and bacterial soft rot disease caused by Pectobacterium carotovorum. Expression of c-lyzozyme gene plays an important role in increasing the resistance of potato plants to bacterial diseases.

• Korean Journal of Applied Biomechanics
• /
• v.21 no.5
• /
• pp.511-520
• /
• 2011

The purpose of this study was to provide scientific information to track and field coaches and athletes through the analyses of the biomechanics characteristics of the top 4 sprinters in the men's 100 m final in the IAAF World Championships Daegu 2011. Twelve video cameras (Sony, Japan) were used to capture the mid portion of the race (40 m - 70 m) with a sampling frequency of 60Hz. Biomechanical variables including the right ankle, knee and hip angles, the trunk angle, and the velocity of center of mass (COM) in the running direction, were calculated with the Kwon 3D program (Visol, Korea). Correlation coefficients between the COM velocity and each variables were calculated using Matlab 2008a (MathWorks, USA) at an alpha level of 0.05. The findings indicated that Yohan Blake (JAM) showed greater range of motion at the ankle and hip. Walter Dix(USA) showed greater knee and trunk movement, and Kim Collins (SKN) showed more dorsi-flexed and extended trunk angles during the race. Finally, Christophe Lemaitre (FRA) showed more plantar-flexed ankle with a less trunk motion, throughout the analyzed race.

• Korean Journal of Applied Biomechanics
• /
• v.23 no.4
• /
• pp.295-306
• /
• 2013

The purpose of this study was to provide high school male shot putters training methods of gliding and delivery motion through comparative analysis of kinematic characteristics. To accomplish this purpose, three dimensional motion analysis was performed for the subjects(PKC, KKH, YDL) who participated in high school male shot putter competition on 92nd (2011), 93rd (2013) National Sports Festival. The subjects were filmed by four Sony HXR-MC2000 video cameras with 60 fields/s. The three-dimensional kinematic data of the glide, conversion and delivery phase were obtained by Kwon3d 3.1 version. The data of the shoulder rotational angles and projection angles were calculated with Matlab R2009a. The following conclusions had been made. With the analysis of the gliding and stance length ratio, the gliding length was shorter at the TG than the SG with short-long technique but the gliding and stance length ratio was 46.8:53.2% respectively. The deviation of the shots trajectory from APSS(Athlete-plus-shot-system) revealed that the PKC showed similar to "n-a-b-c-I" of skilled S-shape type, KKH and YDL showed "n-a-d-f-I'" of unskilled type. Furthermore, they showed smaller radial distance from the central axis of the APSS and the shots were away from the linear trajectory. From this characteristics, The PKC who performed more TG than SG had shorter glide with S-shape of APSS(skilled type) showed the better record than others with technical skill. But KKH and YDL had bigger glide ratio with "n-a-d-f-I'" of unskilled type and improved their records with technical factor. The projection factor had an effect on the record directly. Because PKC maintained more lower glide and transition posture with momentum transfer through COG's rapid horizontal velocity respectively the subject possessed the characteristics of high horizontal and vertical velocity with large turning radius from shot putter to APSS.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.24 no.2
• /
• pp.361-368
• /
• 1994

Radiographic planning is needed for implant placement in order to determine implant length, jaw bone volume, anatomical stucture and so on. Radiographic examination includes conventional radiography, conventional tomography and CT scan. The most accurate mesurement can be obtained from CT scan. For the cross-sectional view of mandible, CT scan reconstruction is generally needed. But the cross-sectional view of mandible can be reformed by personal computer. This study was performed to examine the clinical usefulness of reformed image using personal computer in comparison with CT scan reconstructed image. CT axial slices of 4 mandibles of 4 volunteers were used. Digital imaging system was composed of Macintosh Ⅱ ci computer, high resolution Sony XC-77 CCD camera, Quick Capture frame grabber board and 'NIH Image' program. Seven reconstructed cross-sectional images within CT machine(CT group) were obtained. And seven reformed cross-sectional images(PC group) after digitization of CT axial slices into the personal computer were obtained. PC group was compared with CT group in the objective and subjective aspects. The results were as follow: 1. Measurement of mandibular height & width in both group showed insignificant difference(P>0.05). 2. Subjective assessment of the mandibular canal in both group showed insignificant difference(P>0.05). 3. Image reformation using personal computer could provide panoramic view, which could not be obtained in CT scan reconstruction.

• Korean Journal of Applied Biomechanics
• /
• v.19 no.3
• /
• pp.509-517
• /
• 2009

The purpose of this study was to investigate the effective posture for air pistol shooting. Participants were 3 male athletes of shooting with at least five years of experience and another group of 3 males athletes with less than three years of experience. For the purpose, the shooting motion was analysed using three dimensional image technology. Data from each event for the two groups, competent and less competent ones, were compared to see the differences from the kinematical point of view. Time of period in competent group was longer than less competent group during the shooting posture. Displacement of center of mass and pistol about medial/lateral and antero/posterior in competent group was little than less competent group from aim to shooting. And these result were effect to the velocity. Distance and time in competent group within coaching machine were smaller than less competent group. To the result, it was appear that precision of aim in competent group was higher than less competent group.

• Korean Journal of Applied Biomechanics
• /
• v.26 no.3
• /
• pp.249-255
• /
• 2016

Objective: This purpose of this study was to analyze the relationship between dimensionless leg stiffness and kinetic variables during gait performance, and its modulation with body weight. Method: The study sample consisted of 10 young women divided into 2 groups (Control, n=5 and Obese, n=5). Four camcorders (HDR-HC7/HDV 1080i, Sony Corp, Japan) and one force plate (AMTI., USA) were used to analyze the vertical ground reaction force (GRF) variables, center of pressure (COP), low limb joint angle, position of pelvis center and leg lengths during the stance phase of the gait cycle. Results: Our results revealed that the center of mass (COM) displacement velocity along the y-axis was significantly higher in the obese group than that in control subjects. Displacement in the position of the center of the pelvis center (Z-axis) was also significantly higher in the obese group than that in control subjects. In addition, the peak vertical force (PVF) and dimensionless leg stiffness were also significantly higher in the obese group. However, when normalized to the body weight, the PVF did not show a significant between-group difference. When normalized to the leg length, the PVF and stiffness were both lower in the obese group than in control subjects. Conclusion: In the context of performance, we concluded that increased dimensionless leg stiffness during the gait cycle is associated with increased velocity of COM, PVF, and the change in leg lengths (%).

• Korean Journal of Applied Biomechanics
• /
• v.17 no.4
• /
• pp.65-71
• /
• 2007

The purpose of this study was to investigate variability of kinematic factors affecting the record in women's javelin throwing. For this study, 8 female-javelin thrower participated in this experiment. The three digital video cameras (Sony, 120x) were used to record motions. Kwon3D 2.1 was used to process data and they were analyzed with Excell for factors. The sampling rate of a camera was 60Hz and shutter speed of a camera was 1/1000sec. The coordinate data were filtered using a fourth-order Butterworth low pass filtering with an estimated optimum cut-off frequency of 6Hz. The results were as follows: 1. From cross step to landing of delivery, the average velocities of CoM of non-dominant athletes were greater than dominant athletes and those of CoM of non-dominant athletes less than dominant athletes, but at release dominant athletes had a lower average velocity and a variability than non-dominant athletes. 2. From cross step to landing of delivery, the average throwing velocities and variabilities of a javelin of dominant athletes were greater than dominant athletes, but at release, dominant athletes had a higher velocity than dominant athletes and had a equal variability. 3. At every events, a forward or backward angles and variabilities of non-dominant athletes were greater than dominant athletes. 4. From cross step to landing of delivery, dominant athletes' elbow average angles were greater than non-dominant athletes and the variabilities of latter less than non-dominant athletes, but at release dominant athletes' variabilities were smaller than non-dominant athletes. 5. At landing of delivery, dominant athletes' knee average angles and variabilities of a supporting foot were a greater than non-dominant athletes, and at release, dominant athletes' knee average angles was a greater but variabilities less than non-dominant athletes. In conclusion, the dominant threw javelins fast while having stable postures and the range of elbow's angle large.

• Journal of Science of Art and Design
• /
• v.2
• /
• pp.128-160
• /
• 2000

The objective of this study is to establish a theoretical framework of factors and strategies for success , by probing into design management strategies and the resulting product development details of firms from many parts of the world that improved their images and competitiveness through industrial design. As a means for a company to successfully develop products and to survive, strategies for successful product development were unfolded by many leading businesses of industrial design, whose methods and strategies were respectively unique. International companies such as Philips, Sony, Braun, Ford, and Alessi employed industrial design to not only renew their brand perceptions, but also added values to human life by embedding exclusive designs that customers prefer in their products. They have used design as a business strategic tool, whose elemental processes are, planning, organizing, directing, and controlling. In conclusion, the successful strategies of the leading global companies' design management and product development share the following First, these companies seek design strategies that foresee upcoming changes and are ahead of their time. Second, the CEO is aware of the importance of design, has an appreciative eye for design, and puts in effort into supporting and developing his or her design sector. Third, the director is provided with the conditions in which he or she can take control of one's tasks, and has the abilities and qualities to provide visions for the future. Fourth, the product development team uses original and logical processes and is highly organized. Fifth, the design organization effectively utilizes necessary experts of internal and external company. Sixth, the firm produces innovative products that meet the customers' demand and predict the future. Seventh, the products developed shall employ cutting-edge technologies and are new and original. Eighth, the product must have an identity as a product that represents the company.