• Journal of Radiation Protection and Research
• /
• v.28 no.4
• /
• pp.263-270
• /
• 2003

Monte Carlo simulation has been peformed to induce optimized parameters of the detector head of gamma camera for the diagnosis of breast cancer and to evaluate it under the diagnosis condition of the breast cancer. For the simulation, we used Tungsten collimator, having a lattice structured array with holes of $3mm{\times}3mm$ and septal thickness of 0.25 mm, which are corresponding to the pixellated photosensor. For driving optimum parameters we used Trade-Offs procedure between the geometric efficiency and the spatial resolution, varying the detector head components. In order to pre-evaluate the performance of the optimized detector head, we assumed diagnosis condition that the breast tumor is located in the middle of phantom with various sizes and its location is 25 mm from the collimator surface, considering background count caused by radiation sources from other organs. It was shown that the performance of the optimized detector head can be degraded according to the breast cancer size and the background count under real diagnosis conditions of breast cancer. Therefore, it is concluded that the spatial resolution, which is used as an indicator to distinguish the various sizes of breast cancer and is dependent on the characteristic of the detector head, appears to be meaningless in early diagnosis of the breast cancer.

• The Journal of the Korea Contents Association
• /
• v.13 no.11
• /
• pp.451-460
• /
• 2013

Project to deal with cultural archetype as a material for creation to develop modern one has continued. But it would be meaningless if cultural archetype is simply reproduced into modern one with modern medium so that such contents cannot see through desire that the general public, that is, contemporary recipients want. This is because desire of people who lived in the past is not completely same as one of modern people. This study began to make convergence from Bulgasalee(不可殺伊) as a Korean cultural archetype to cultural contents fit to modern times. To develop creative character based on ground for existing Bulgasalee(不可殺伊), these were investigated - method and meaning of modern transformation for classics, economic value of the character, and examples to understand direction of future development. Bulgasalee(不可殺伊) as a Korean cultural archetype is Korean style monster where wish of contemporary people was reflected so that it has character of anti-war and hero. To eat iron and be related to fire is a unique character that only Bulgasalee(不可殺伊) has. Bulgasalee(不可殺伊) re-born in modern sense based on such characters is equipped with tool to treat iron as arms and to it, image of fireman is reflected. It is thought that this study not only suggested character for successful modern transformation of cultural archetype but also newly developed value that the character has.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.9
• /
• pp.30-41
• /
• 2018

This phenomenological study aims to explore Nursing Students' Experiences who have experienced team-based learning (TBL). The purpose of this study is to contribute to fostering professional nurses required in the clinical field by improving the learning outcomes by applying the TBL classes. The study participants were seven students of the nursing department who took TBL classes in adult nursing classes. The data were collected through participating observations and in-depth interviews, and analyzed using Colaizzi's phenomenological methods. As a result of the study, nine conceptual descriptions and five theme clusters were derived. The major theme clusters for the experiences of students were 'Dedication to best results', 'Self-led learning attitudes are formed', 'Becoming a communal knowledge creator', 'Active class time', and 'Meaningless peer evaluation'. Nine conceptual descriptions were 'Doing one's best to fulfill one's role', 'Preparing for the class with the pre-learning', 'Forming confidence through pre-learning', 'Solving problems through interaction with friends', 'Becoming a mentor to each other', 'Working together to resolve issues', 'Intimacy formed', 'A lively class', and 'Peer evaluation with familiarity'. This study contributes to the improvement of the learning outcomes of the nursing students by enabling learner-centered classes and self-led learning, thereby contributing to fostering the professional nursing manpower required in the clinical field.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.8 no.2
• /
• pp.109-116
• /
• 1988

The strength and load of structure are varied with the Passage of time, and become a process of probability. It is possible to estimate the reliability from the relation between strength and load. Considering the safety, It is reasonable to estimate allowable stress from the safety factor based on the reliability. In this study, the method to estimate probability of fracture, which is index of reliability for rail subjeict to long term fatigue load were examined. In estimation of reliablity it is meaningless to evaluate numerical value especially this difficult case estimating parameter of random variable. To overcome this problem, conventional design method estimating relative reliability were proposed. In this study the Cornell method were examined. The uncertainity of random variale, ie coefficient of variation which is the index of variation of strength and load were considered. The effect of uncertainity related to probability of fracture, and safety factor based on reliability were examined. The results of this study are followed. The reliability of weld metal were influenced by variation of strength more then load, and base metal were influenced by load. It is confirmed that the allowable stress range calculating with factor of safety based an reliability is conservative.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2000.11b
• /
• pp.489-497
• /
• 2000

Since Chinese cabbages weigh 3 to 5kgf and are big in size at the time of harvest, handling operations such as harvesting, loading and unloading including transportation require the highest labor demand among all other cultivation processes. Recently, though several cabbage harvesters were developed in Japan and Europe, those harvesters were not suitable for Chinese cabbages cultivated in Korea because of the size and shape. The cabbage harvester is almost meaningless without any proper cabbage piling and pallet unloading mechanism. Most harvesters developed so far adopted a sort of slide and free falling way in collecting cabbages into the pallet. Three or four labors are usually required for cleaning incoming cabbages and loading those in the pallet. Because of the required time for piling cabbages without severe damage and the required space capacity to carry empty and loaded pallets, harvesting speed should be adjusted in accordance with time required for consecutive operations. Up to now, any automatic or semi-automatic collecting device has not been developed in the world to pile cabbages on the layer one by one into the pallet in the ordered way with little damage and to unload pallet from the harvester continuously during the harvest process. To compromise system expenses and function, Semi-automatic cabbage piling and pallet unloading mechanism was devised and it required one labor. The foldable mesh pallet with a size of 1050mm x 1050mm x 1000mm and holding capacity of around 70 cabbages was utilized. The prototype for piling and unloading mechanism was composed of three parts such as feeding device, automatic piling device with retractable bellows, and pallet unloading device. Prior to developing the prototype, the geometric properties and the amount of the damage of the cabbage caused during the piling operation were investigated. Considering the height of the pallet, a series of cabbage carrying plates were mounted to the bracket chain to lift and to carry cabbages to the loading device. Indoor laboratory experiments showed that the cabbage carrying chain conveyor worked successfully. Considering the conveying speed 0.46m/sec of the pull up belt from the cabbages on the ground, the speed of cabbage carrying chain conveyor worked property in the range of 0.26m/sec to 0.36m/sec. The system allowed the operator to modify the position of cabbage slightly. Overall system worked successfully resulting into almost same capacity without severe damage to the cabbage as human did.

• Applied Microscopy
• /
• v.40 no.3
• /
• pp.139-145
• /
• 2010

This study was intended to identify the effectiveness of Lithospermum erythrorhizon in the UVB-damaged mouse skin. The C57BL/6 mouse that weighted about 18 g were divided into three groups; the control group (A group), the UVB irradiated group (B group), and the group treated with Lithospermum erythrorhizon extracts after UVB irradiation (C group). In the results of superoxidase dismutant(SOD) activities, the C group was meaningfully lower at the 48hrs, 120 hrs, and 168 hrs group than B group (p<0.05). In the result of catalase(CAT) activities, the C group was decreased at the 120 hrs and 168 hrs group, but meaningless (p>0.05). In the result of light micrograph observation, the B group observed sunburn cells in the epidermis and acute inflammation in the dermis at the 24 hrs and 48 hrs. And proliferation of the epidermis and the stratum granulosum, and found the hyperkertosis at the 72 hrs, 120 hrs, and 168 hrs group than C group. The C group alleviated inflammation in the dermis than B group at the 24 hrs and 48 hrs. And inhibited the proliferation of the epidermis at the 72 hrs, 120 hrs, and 168 hrs groups than B group. In conclusion, Lithospermum erythrorhizon water extracts may protect the UVB-damaged mouse skin.

• Journal of Korean Society for Geospatial Information Science
• /
• v.23 no.1
• /
• pp.73-79
• /
• 2015

Recently, BIM proliferates at high speeds so that BIM planning is trying to be used in various kinds of engineering. However, when using different software during design phase and construction phase, the problem of mutual compatibility is coming out. Even the BIM technology has been used or the practical applicability has been made into result, it would be fair to say that BIM has limitations in the visual level. In this research, it is meaningless to obtain the BIM result as the primary purpose. As the usefulness of it is judged incomplete, we committed to master the trend and problems of terrain spatial information systems and BIM. Furthermore, the plan of building the BIM in the civil field, especially the civil-BIM based on the technology ofterrain spatial information has been presented. It can be judged through this research that the high-capacity DB of BIM occurred during the whole process may cause poor performance of the following stage the structure system which connects the terrain spatial information and civil-BIM. In order to manage the optimal full cycle, the spatial analysis technology of the stages after choosing the DB has been described.

• Science of Emotion and Sensibility
• /
• v.20 no.1
• /
• pp.31-40
• /
• 2017

The present study used one of research techniques which is eye gaze tracking for neuromarketing. When pupil's size of men dilated over than three sigma (0.135%), the interest and eye movement in observation were measured. According to statistical analysis of previous studies, three sigma range is meaningful therefore sigma range was used as operational definition because 'pupil dilatation' is difficult to be define in eye gaze tracking data. Pictures of basketball games were selected as visual stimuli and 90% effective ratio of total 7,200 data were calculated. Thus, 29 of 34 participants were used for test. Pupil's size was calculated by applying pupil's width and height into a formular; [Pupil's size = Pupil width/2${\times}$Pupil height/$2{\times}{\pi}$]. In conclusion, billboard utilized for sports marketing had meaningless effects because gaze frequency to basketball player and surrounding environment was higher than that to billboard when participantsas game spectators diltaed their pupil's size over than three sigma. Thus, it was required using new marketing strategies like neuromarketing to increase utility through the present study.

• Restorative Dentistry and Endodontics
• /
• v.24 no.4
• /
• pp.578-584
• /
• 1999

The purpose of this experiment was to determine: (1) the safe automatic apical reverse setting that prevents overinstrumentation of the root canal, using Tri Auto ZX$^{(R)}$ and (2) the effect of various irrigant on such instrumentation. The instrumentation was carried out with the automatic apical reverse setting of 0.5, 1.0, 1.5, and 2.0. The root canal irrigants used in usual manner were normal saline(0.9%), NaOCl(2.5%), and RC Prep$^{(R)}$. For each reverse setting and each irrigant, ten teeth were used with the total of 120 teeth. The distance between the file tip and the apical constriction was determined by stereomicroscope using the point that the file began to rotate in reverse direction. When the reverse setting mode was set to 0.5, 18 of 30 were overinstrumented. If these were discriminated by irrigant, 10 of 6 with 0.9% saline, 10 of 6 with NaOCl, and 10 of 6 with RC Prep$^{(R)}$ has the file tip located 0.57${\pm}$0.30mm, 0.73${\pm}$0.39mm, and 0.26${\pm}$0.25mm beyond the apical constriction respectively. In 1.0 setting 15 of 29 were over the apical constriction, and the distribution was 6 in saline, 5 in NaOCl, and 4 in RC Prep$^{(R)}$. The mean distance over the apical constriction was 0.28${\pm}$0.13mm with saline, 0.75${\pm}$0.61mm with NaOCl, and 0.25${\pm}$0.17mm with RC Prep$^{(R)}$. When the autoatic reverse mode was set to 1.5, and 2.0, 5, and 1 teeth were found to be overinstrumented in respective settings. But there were large variations in overinstrumented distances when an attempt was made to compare the effect of irrigants on this overinstrumentations and they were meaningless for the small sample size. When all of the autoreverse setting were combined to compare the number of overinstrumented teeth with each irrigant, there were no significant differences (14 for normal saline, 12 for NaOCl, 13 for RC Prep$^{(R)}$). When 0.5 or 1.0 automatic apical reverse setting mode was used the Tri Auto ZX$^{(R)}$ in clinical application, the possibility of overinstrumentation beyond the apical constriction exists in 55.9% of cases. Therefore 1.5 or 2.0 setting is safer for the preparation inside the canal but this type setting needs additional apical hand preparation of the root canal because the accuracy is lower than 0.5 or 1.0 setting.

• Journal of the Korea Concrete Institute
• /
• v.23 no.3
• /
• pp.281-287
• /
• 2011

Recently, bridge construction technology has made great progress from development of high performance materials and new bridge types. However, most technology are based on methods of cast-in-place and material cost saving. The method of cast-in-place concrete causes environmental damages and costumer complaints. Especially, under bad weather conditions, the construction can not proceed. To overcome these disadvantages, new construction methods were developed to reduce construction time. These methods are called precast method. Most prefabricated methods have been applied to superstructure constructions of bridges, but very minutely applied to substructure constructions. The most important agendas on precast method are light weight and transportability of the precasted members, because very strict transporting specifications exist for road transportation of the precasted members. For example, the weight and length of coping members may be larger than the available transporting vehicles. Although column is constructed by precast method to save construction time, if coping member is constructed by cast-in-place method, then the column construction time reduction becomes meaningless. Therefore, in this study, a new precast coping member and a connecting system of column-coping member are proposed. The proposed method is verified by analyzing their ultimate performance through analysis and experimental study.