• Journal of the Korea Society of Computer and Information
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• v.17 no.11
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• pp.33-38
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• 2012

An free-fall object is received only force of gravity. Movement that only accept gravity is free-fall movement, and a free-falling object is free falling body. In other words, free falling body is only freely falling objects under the influence of gravity, regardless of the initial state of objects movement. In this paper, we assume, ignoring the resistance of the air, and the free-fall acceleration by the height does not change within the range of the short distance in the vertical direction. Under these assumptions, we can know about time and maximum height to reach the peak point from jumping vertically upward direction, time and speed of the car return to the starting position, and time and speed when the car fall to the ground. It can be measured by jumping degree and risk of accident from car or motorcycle in telematics.

• Structural Engineering and Mechanics
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• v.20 no.5
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• pp.505-526
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• 2005

The influence of the inter-story structural pounding on the seismic behaviour of adjacent multistory reinforced concrete structures with unequal total heights and different story heights is investigated. Although inter-story pounding is a common case in practice, it has not been studied before in the literature as far as the authors are aware. Fifty two pounding cases, each one for two different seismic excitations, are examined. From the results it can be deduced that: (i) The most important issue in the inter-story pounding is the local effect on the external column of the tall building that suffers the impact from the upper floor slab of the adjacent shorter structure. (ii) The ductility demands for this column are increased comparing with the ones without the pounding effect. In the cases that the two buildings are in contact these demands appear to be critical since they are higher than the available ductility values. In the cases that there is a small distance between the interacting buildings the ductility demands of this column are also higher than the ones of the same column without the pounding effect but they appear to be lower than the available ductility values. (iii) It has to be stressed that in all the examined cases the developed shear forces of this column exceeded the shear strength. Thus, it can be concluded that in inter-story pounding cases the column that suffers the impact is always in a critical condition due to shear action and, furthermore, in the cases that the two structures are in contact from the beginning this column appears to be critical due to high ductility demands as well. The consequences of the impact can be very severe for the integrity of the column and may be a primary cause for the initiation of the collapse of the structure. This means that special measures have to be taken in the design process first for the critically increased shear demands and secondly for the high ductility demands.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9529-9534
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• 2014

Background: Cancer staging enables planning for the best treatments, evaluation of prognosis, and predictions for survival. The Collaborative Stage (CS) system makes it possible to significantly reduce the proportion of patients labeled at an "unknown" stage as well as discrepancies among different staging systems. This study aims to analyze the factors that influence the accuracy and validity of CS data. Materials and Methods: Data were randomly selected (233 cases) from stomach cancer cases enrolled for CS survey at the Korea Central Cancer Registry. Two questionnaires were used to assess CS values for each case and to review the cancer registration environment for each hospital. Data were analyzed in terms of the relationships between the time spent for acquisition and registration of CS information, environments relating to cancer registration in the hospitals, and document sources of CS information for each item. Results: The time for extracting and registering data was found to be shorter when the hospitals had prior experience gained from participating in a CS pilot study and when they were equipped with full-time cancer registrars. Evaluation of the CS information according to medical record sources found that the percentage of items missing for Site Specific Factor (SSF) was 30% higher than for other CS variables. Errors in CS coding were found in variables such as "CS Extension," "CS Lymph Nodes," "CS Metastasis at Diagnosis," and "SSF25 Involvement of Cardia and Distance from Esophagogastric Junction (EGJ)." Conclusions: To build CS system data that are reliable for cancer registration and clinical research, the following components are required: 1) training programs for medical records administrators; 2) supporting materials to promote active participation; and 3) format development to improve registration validity.

• Tunnel and Underground Space
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• v.2 no.2
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• pp.212-223
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• 1992

The distinct element method(DEM) si well suited to the kinematic analysis of blocky rock masses. Two distinctive problems, a rock avalache and tunnel in jointed rock masses, are chosen to apply the DEM which is based on perfectly rigid behaviour of blocks. Investigated for both problems are the effects of the input parameters such as contact stiffnesses, friction coefficient and damping property. Using various types of models of the avalanche and tunne, an extensive parametric study is done to gain experiences in the method, and then to alleviate difficulties in determining parameter values suitable for a given problem. The coefficient of frictio has significant effects on all aspects of avalanche motion(travel distance, velocity and travel time), while the stiffnesses affect the rebounding and jumping motions after collision. The motion predicted by the models having single and mutiple blocks agrees well to the observations reported on the actual avalache. For the tunnel problem, the behaviour of the key block in an example tunnel is compared by testing values of the input parameters. The stability of the tunnel is dependent primarily on the friction coefficient, while the stiffness and damping properties influence the block velocity. The kinematic stability of a tunnel for underground unclear waste repository is analyzed using the joint geometry data(orientation, spacing and persistence) occurred in a tailrace tunnel. Allowing a small deviation to the mean orientation results in different modes of failure of the rock blocks around the tunnel. Of all parameters tested, the most important to the stability of the tunnel in blocky rock masses are the geometry of the blocks generated by mapping the joint and tunnel surfaces in 3-dimensions and also the friction coefficient of the joints particularly for the stability of the side walls.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.645-650
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• 2017

It is a system that controls temperature, humidity and fine-dust to make interior environment more comfortable for modern people who spend 90% of the time in indoor. In an experiment of finding which one of temperature and humidity influence more to discomfort index, for a fixed temperature of 21, discomfort index increased by 0.1 with a 1 change of humidity, and for a fixed humidity of 40, discomfort index increased by 1.2 with a 1 change of temperature. As a result, it was found that the temperature is more influential than the humidity to discomfort index. In an experiment of measuring communicational limitation of Bluetooth, the communication was possible for at most 30 meters without obstacles. With high obstacles like walls or steel bars, it was able to penetrate at most 2 obstacles and maximum distance which it can communicate was 10 meters for just one high molecule obstacle.

• Journal of Environmental Science International
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• v.21 no.2
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• pp.241-251
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• 2012

The emissions of several air pollutants ($NO_x$, CO, VOCs, etc.) for the replacement of all diesel buses by Compressed Natural Gas (CNG) buses were estimated in the Busan Metropolitan Area (BMA). These emissions were calculated from emission factors considering the different driving speeds with bus routes, distance traveled, and deterioration factors. For the purpose of this study, three categories of fuel type were selected: (1) the combination of diesel (65%) and CNG buses (35%) (DSL+CNG case), (2) all diesel buses (DSL case), and (3) all CNG buses (CNG case). The emissions of $NO_x$ and CO in the CNG case were estimated to be significant decreases (by about 50% and 98%, respectively) relative to the DSL case. Conversely, the emission of VOCs (980.7 ton/year) in the CNG case were a factor of 3.3 higher than that (299.8 ton/year) in the DSL case. In addition, the diurnal variations of emissions between two city buses (e.g. diesel and CNG) and all other vehicles were distinctly different because the two city buses operate at a regular time interval. Our overall results suggest the possibility that the pollutant emissions from the CNG buses can exert less influence on air quality in the target area than those from the diesel buses.

• Journal of Periodontal and Implant Science
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• v.48 no.3
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• pp.174-181
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• 2018

Purpose: The aims of the present study were to quantitatively assess graft height changes after sinus lift procedures and to analyze the factors that influenced graft height changes, including the residual bone height before surgery, surgical approach, and tooth type. Methods: A total of 39 maxillary posterior implants placed during a simultaneous sinus lift procedure were evaluated. Panoramic radiographs of all patients were taken immediately after implant installation and at 3 months, 6 months, 1 year, 2 years, and 3 years. To analyze graft height changes over time, we measured the distance between the implant platform and the base of the grafted sinus floor at 3 locations. The radiographs were analyzed by a single examiner. Results: Graft height tended to decrease over time, and a statistically significant difference was observed at 2 years compared to baseline (P<0.05). There was no statistically significant difference in graft height change according to the surgical approach or tooth type. For residual bone height, a statistically significant difference in graft height change was found between those with 4-7 mm of residual bone height and those with ${\geq}7mm$ (P<0.05). Conclusions: Graft height after sinus lift procedures significantly decreased at 2 years compared to baseline after sinus augmentation. Further studies should be done with controlled variables, and prospective studies with 3-dimensional images are needed to clarify the factors that influence graft height changes.

• Journal of the Korean Institute of Rural Architecture
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• v.17 no.1
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• pp.73-81
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• 2015

The purpose of this study is to analyze the approach characteristics, relation to other facilities, and current status focusing on 28 total of exhibition-culture facilities in Gangneung. The results are following as. First, 19 facilities are located in urban area and nine are located in country side. With locational characteristics of Gangneung which is mountains in west and sea to east, three are located in high hill side and four are in sea shore among nine facilities. Facilities in urban area converge to Gungpodae and Ojukhuk which are symbol space in Gangneung. Those facilities started to have been increased from 1990s and rapidly increased from 2000s. The reason is that people have been interested in culture and art in society in general. In building structure, buildings related with traditional contents were constructed with wooden structure while buildings have been mainly constructed with modern ways such as steel and reinforced concrete structure. Second, the 28 facilities are classified into three types by function of other space or facilities within same a site or a building. The three types are themselves usage only, multi-function, and park type. The multi-function type is re-classified into two; public type and commercial type. Those functions have changed according to changes of society and times. Finally, for approaching to the exhibition-culture facilities with general transportation, the mean distance from the closest bus stop to those facilities each is 280m and 27 facilities are located within 670m from the closest bus stop. For approaching way using by car creates movement along road-building site-parking space-main entrance of building. When based on main entrance by the movement, parking space located in front side of main entrance is the largest, next is in the side, and the least is in back side. Various factors such as approaching form from road to parking space and space size between main entrance and parking space influence to approaching ways of exhibition-culture facilities in Gangneung.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.139-145
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• 2004

It is well known that human errors is involved in most of maritime accidents. For the purpose of reducing the influence of human elements on maritime activities, it is necessary to identify the human unsafe acts in those activities. The commonly used methods in identification of human unsafe acts are maritime accident statistics or case analysis. With the statistics data, people could roughly identify what kinds of unsafe acts or human errors have played active role in the accident, however, they often neglected some active unsafe acts while overestimated some mini-unsafe acts because of the inherent shortcoming of the methods. There should be some more accurate approaches for human error identification in maritime accidents. In this paper, the application of technique called grey relational analysis (GRA) into the identification of human unsafe acts is presented. GRA is used to examine the extent of connections between two digits by applying the, methodology of departing and scattering measurement to actual distance measurement. Based on the statistics data of maritime accidents occurred in Chinese waters in last 10years, the relationship between the happening times of maritime accidents and that of unsafe acts are established with GRA. In accordance with the value of grey relational grade, the identified main human unsafe acts involved in maritime accidents are ranked in following orders: improper lookout, improper use of radar and equivalent equipment, error of judgment, act not in time, improper communication, improper shiphandling, use of unsafe speed, violating the rule and ignorance of good seamanship. The result shows that GRA is an effective and practical technique in improving the accuracy of human unsafe acts identification.

• Fashion & Textile Research Journal
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• v.4 no.2
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• pp.145-155
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• 2002

In order to investigate how upper limb motion gives influence on clothing, this study measured tests by following standards: Front Vertical motion, Side-Vertical motion, and Horizontal motion. For this study, the procedures in the order of alphabet are applied. A. Eeach of testee's pattern was copied by the motion with a method of tight fitting technique. B. Analyzing each of the size-change on measuring item. C. Studying the moving aspects at each datum points. The results shows that the biggest change can be found in the following items. 1) In vertical motion of F4 (the length to shoulder point from A-point) 2) In horizontal motion of F5 (the length to front-width point from A-point), the check-result gained by checking the notice between motions shows that the most noticeable items are F4 (the length to shoulder point from A-point), F5 (the length to front-width point from A-point), F6 (the length to armpit point from A-point), B7 (the length to side-waist point from B-point). In result of the study of datum point's movement by motion, the items which were measured with the longest on straight-distance in vertical motion are the front and rear-shoulder, and the rear-shoulder, front-armpit in horizontal motion each. In the movement of each datum points by length, the check-result gained by checking the notice between motions shows that the most remarkable item is the front-shoulder.