• Fire Science and Engineering
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• v.24 no.4
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• pp.109-115
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• 2010

Maximum pressure difference in central core type 80th super_tall buildings was estimated as 75 Pa during no outside wind due to the winter stack effect. Maximum pressure difference of 225 Pa can be obtained depending on the location of air injection fan during the stairway pressurization at fire. Bottom_only air injection system provided the best results in the sense of required air flow rates and pressure distributions. Top_only air supply system was estimated as the worst for this country. It revealed that the decrease of the temperature in the stairway due to the cold outside air injection reduced the required flow rates of the fan and significantly changed the distribution of pressure differences.

• Journal of Astronomy and Space Sciences
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• v.34 no.4
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• pp.315-330
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• 2017

Halo coronal mass ejections (CMEs) originating from solar activities give rise to geomagnetic storms when they reach the Earth. Variations in the geomagnetic field during a geomagnetic storm can damage satellites, communication systems, electrical power grids, and power systems, and induce currents. Therefore, automated techniques for detecting and analyzing halo CMEs have been eliciting increasing attention for the monitoring and prediction of the space weather environment. In this study, we developed an algorithm to sense and detect halo CMEs using large angle and spectrometric coronagraph (LASCO) C3 coronagraph images from the solar and heliospheric observatory (SOHO) satellite. In addition, we developed an image processing technique to derive the morphological and dynamical characteristics of halo CMEs, namely, the source location, width, actual CME speed, and arrival time at a 21.5 solar radius. The proposed halo CME automatic analysis model was validated using a model of the past three halo CME events. As a result, a solar event that occurred at 03:38 UT on Mar. 23, 2014 was predicted to arrive at Earth at 23:00 UT on Mar. 25, whereas the actual arrival time was at 04:30 UT on Mar. 26, which is a difference of 5 hr and 30 min. In addition, a solar event that occurred at 12:55 UT on Apr. 18, 2014 was estimated to arrive at Earth at 16:00 UT on Apr. 20, which is 4 hr ahead of the actual arrival time of 20:00 UT on the same day. However, the estimation error was reduced significantly compared to the ENLIL model. As a further study, the model will be applied to many more events for validation and testing, and after such tests are completed, on-line service will be provided at the Korean Space Weather Center to detect halo CMEs and derive the model parameters.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.3
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• pp.57-63
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• 2002

This landscape design was proposed for the Buchon Special School Competition, held by the Kyonggi Province Office of Education. The authors collaborated on this design and won first prize in November of 2001. In the design proposal, on the basis of the knowledge of; mentally retarded children the children's activities, nature and health, and the healing gardens, the special school outdoor spaces were designed to meet the particular needs of the users. The school outdoor spaces are design for various types of users-children, adolescents, parents, siblings, staff, volunteers and visitors. The following are some of the basis concerns in the design of the school outdoor spaces : garden site planning, garden location, security, microclimate, entering and exiting, accessibility, usability, user group territories, supervision, attracting trained volunteers, a range of high-quality social settings, accommodation of different student types, accommodation of needs for both challenge and rest, child nature interaction, diversity of natural settings, hands-on activity, integrating the arts, and maintenance. The following are some of the major features in the design of school outdoor spaces : pleasant and inviting entry areas, sports grounds with different levels of challenge, gardens with plants having strong fragrances and/or tactile qualities, resting places with many types and forms of seating and weather-mitigating features, play grounds for all student types, roof gardens for users to experience nature in man-made environments, and walkways and winding paths with various trees, shrubs and flowers. In the special school outdoor spaces, people would perceive a unique sense of place through the various types of spaces and features described above. An example of the true meaning of a playing and resting place and a restorative and therapeutic environment is provided in the school outdoor spaces.

• The Journal of the Acoustical Society of Korea
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• v.16 no.1
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• pp.47-53
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• 1997

This paper concerns an efficient approach to forming a beam pattern of a microphone array to deal with broadband signals such as speech in a teleconference. A numerical method is proposed to find updated location of sidelobes for equalizaing the sidelobes via perturbation of array parameters such as array weight or microphone spacing. Thus the microphone array is optimized in a Dolph-Chebyshev sense such that directional or background noises incident in an array visual range are eliminated efficiently. It is shown that perturbation of microphone spacing yields an optimum pattern more appropriate for dealing with broadband signals than that of array weight. Also, a novel method is proposed to find a beam pattern which is robust with respect to sidelobe in a scanning situation. Computer simulation results are presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1489-1494
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• 2013

Tsunami happens rarely enough to allow a false sense of security, but when they do occur, there may be just minutes or hours for people to reach a safe location. Natural disasters like tsunami are inevitable and it is almost impossible to fully recoup damages caused by the disasters. However, it is possible to minimize the potential risk by developing early warning strategies. GIS modelling with its geoprocessing and analysis capability can play a crucial role in efficient mitigation and management of disaster. This study aims at developing integrated spatial information system processing model supporting tsunami evacuation action planning using geo-information technology such as GIS. The integration process classified into four phases. And in each phase, required input data and GIS processes are decided. The main effort in minimizing casualties in tsunami disaster is to evacuate people from the hazard area before tsunami strikes by means of either horizontal or vertical evacuation. The study provides essential spatial information for local decision making related with people's evacuation in tsunami-prone areas based on a modeling approach transferable to other coastal areas.

• Restorative Dentistry and Endodontics
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• v.7 no.1
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• pp.25-31
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• 1981

One of the most important factors for successful endodontic therapy is an accurate length determination of physiological root apex. Some methods suggested for the measurement of root canal length, include digital-tactile sense and roentgenographic technique with measuring wire, scale and grid. But these methods do not derermine an accurate working length to physiological root apex. Recently electronic measuring devices are used to locate the physiological root apex in root canal length determination and these devices are accepted as an effective apparatus. The 89 patients (116 teeth, 144 canals) among the out-patients of Yonsei University Dental Infirmary, who had had an endodontic treatment in the Department of Operative Dentistry, were measured by the Root-Canal Meter$^{(R)}$ as an electronic device, and radiographs to determine the distribution and location of physiological root apex, then the following results were made: (1) Range of ${\pm}$1mm from the radiographic root apex were present in 88.88% (128 canals) of the subjects. (2) Physiological root apex and radiographic root apex were coincided in 31.94% (46 canals) of the subjects. (3) The actual length of the physiological root apex of the teeth were as follow; A : in the maxillary central incisor : 0.46mm B : in the maxillary lateral incisor : 0.44mm C : in the maxillary canine : 0.44mm D : in the maxillary 1st premolar : a) Buccal : 0.59mm b) Lingual : 0.34mm E : in the maxillary 2nd premolar : 0.54mm F : in the maxillary 1st molar : a) Mesio-buccal : 0.50mm b) Disto-buccal : 0.42mm c) Lingual : 0.56mm G : in the mandibular central incisor : 0.62mm H : in the mandibular lateral incisor : 0.45mm in the mandibular canine : 0.54mm J : in the mandibular 1st premolar : 0.47mm K : in the mandibular 2nd premolar : 0.34mm L : in the mandibular 1st molar : a) Mesio-buccal : 0.54mm b) Mesio-lingual : 0.31mm c) Distal : 0.37mm.

• Journal of Advanced Navigation Technology
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• v.23 no.2
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• pp.194-199
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• 2019

Natural disasters destroy decades of human effort and investments, thereby placing new demands on society for reconstruction and rehabilitation. In most case, the natural phenomena triggering the disasters are beyond human control. In order to solve the problems that the information resources can not be shared among disaster management sectors and their work is hard to be coordinated in city, an idea of application of ubiquitous sense network and ICT technology to model the architecture of the disaster prevention system based on the analysis of characteristics of disasters. The proposed algorithm simulated that it is possible to locate the terminal by linking the direction angle and the estimated position that can be confirmed at the time of stopping, even if the movement direction of the terminal does not move in a certain direction with only a smaller number of mobile base stations. We also confirmed that the proposed algorithms analyzed through simulation are more efficient than existing algorithms.

• Journal of Fashion Business
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• v.25 no.1
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• pp.51-64
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• 2021

The purpose of this study was to develop smart bags that combining fashion-specific trends and smart information technologies such as light-emitting diodes(LED) and optic fibers by grafting marquage techniques that have recently become popular as part of eco-fashion. We applied e-textiles by designing leather tote bags that could show off LED luminescence. A total of two tote bags, a white-colored peacock design and a black-colored paisley design, divided the LED's light-emitting method into two types, incremental lighting and random light-emission to suit each design, and the locations of the optical fibers were also reversed depending upon the design. The production of circuits for the LEDs and optical fibers was based on the design, and a flexible conductive fabric was laser-cut instead of wire line and attached to the circuit-line location. A separate connector was underwent three-dimensional(3D)-modeling and was connected to high-luminosity LEDs and optic fiber bundles. The optical fiber logo part expressed a subtle image using a white-colored LED, which did not offset the LED's sharp luminous effects, suggesting that using LEDs with fiber optics allowed for the expression of each in harmony without being heterogeneous. Overall, the LEDs and fiber optic fabric were well-harmonized in the fashion bag using marquage techniques, and there was no sense of it being a mechanical device. Also, the circuit part was made of conductive fabric, which is an e-textile product that feels the same as a thin, flexible fabric. The study confirmed that the bag was developed as a smart wearable product that could be used in everyday life.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.11
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• pp.1653-1659
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• 2022

Virtual reality content provides users with a high sense of immersion by using HMD devices. However, while wearing the HMD device, it is difficult to determine the user's location or distance from obstacles, resulting in injuries due to physical collisions. In this paper, we propose a reminder module to prevent accidents by notifying the risk of collision with obstacles while wearing the HMD device. The proposed module receives the user's state from the acceleration and gyro sensor and determines the motion that is likely to cause a collision. If there is an obstacle in the expected collision range, a buzzer sounds to the wearer. As a result of the experiment, the accuracy of obstacle detection in the state of wearing the HMD was 86.6% in the 1st stage and 83.3% in the 2nd stage, confirming the performance of the accident prevention reminder.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.2
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• pp.23-36
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• 2010

The purpose of this study is to infer the aspects and significance of Musa basjoo of latter part of Chosun Dynasty by analyzing the planting tendency and planting location of Musa basjoos drawn in total 77 old paintings and the characteristics of the paintings where Musa basjoos appeared, while trying to understand symbolic meanings of floral languages as well as the images and significance of Musa basjoos which appeared in the prose and poetry of Chosun Dynasty, and the results are as follows; With its floral languages of 'waiting', 'parting' and 'beauty', Musa basjoo represented the wealth and resuscitation and it aroused the elegance of hermits in its Taoistic sense. And it also represented 'the unworldliness to get out of transient human affairs' in its Buddhistic sense. Musa basjoos which appeared in 'Garden Custom Painting(庭園雅集圖)', 'Gosa Figure Painting(故事人物圖)' and 'Gyehoe Painting(契會圖)' is considered a device to increase the unworldly atmosphere of gardens and to dignify the elegant meetings of scholars, reflected by the high appearance frequencies of cranes and deer. And it seems that the meaning of Musa basjoo in certain paintings like 'Life-time Paintings(平生圖)', 'Castle City Painting(盛市圖), and 'Cultivating and Weaving Painting(耕織圖)' is an aspiration for wealth and prosperity, and the Musa basjoos planted in temples are considered to have symbolic meanings of aspiration for 'Salvation through Belief' as well as a unworldly meaning which reminds the transiency of human affairs. In addition, the expected effect of experiencing 'the sound of rain falling on the leaves of Musa basjoo' has been pursued, which can be confirmed by the fact that Firmiana simlex with wide leaves similar to Musa basjoo can be frequently spotted near the houses. Meanwhile, Musa basjoos seem to have been planted mainly in front garden or side garden around detached house and Musa basjoos inside the houses seem to have been planted mainly in right side when viewed from the entrance, in relation with the location of bedrooms where it is easier to hear the sounds from the right side of the environment. And the paintings where Musa basjoos appear with strange rocks and bizarre stones among other things have greater part of all the paintings, which is considered a kind of intentional landscaping and a product of mixed materials for elegant appreciation. And the major characters of the painting were involved in the activities of scholars such as arts, and the activities of minor characters were greatly related to their everyday lives. Musa basjoo of Chosun Dynasty in $17^{th}$ and $18^{th}$ century was one of the symbols necessary for description of gardens. And it provided the images of rainy scenes together with scholar culture which had a meaning of self-discipline, and it is assumed that the planting of Musa basjoo with the spirit of cease lessen deavor of a new leaf pushing up the tree and the spirit of resuscitation had the same trace of wheels in the city space of our country as the decline of scholar culture of Chosun Dynasty.