• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.72-83
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• 2015

The purpose of this study was firstly, to explore the design preference, consumer experience and purchasing factors of parents for smart animal toys and secondly, investigate whether there is a difference by children's sex and age. For this purpose, the questionnaire survey was conducted with 344 parents of younger children in Seoul and Gyeonggi Province. As a result, the white or brown colored 20~30cm, dog-type smart toy was preferred and the sound was considered as the most important function. Besides role of toy, smart toy was expected to play as a pet, a friend and a younger sibling. Actually, dog-type smart toy were most frequently purchased. And main satisfied causes were fun, interactivity and design and dissatisfied causes were noise, price, battery life and durability of purchased smart toys. Finally, the important factors in purchasing smart toy were the safety, durability, battery life, sustainable play, education and washability. The parents' preference, customer experience and purchasing factors showed little significant differences according to the sex and the age of the children. This research will be useful in understanding parents purchasing activity of smart animal toys and provide valuable data for function construction, design and service planning necessary to develop the smart animal toy.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.44-53
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• 2021

As environmental issues have emerged worldwide, emission gas regulations have been strengthened. In the construction machinery sector, studies have been actively conducted to utilize the power source of electric motors owing to the increasing demand for zero emissions. In this study, the gear specifications of an electric axle for construction machinery were selected by considering the specifications of the motor, gear tooth contact pattern, and face load factor. The gear strength evaluation was performed at the system level using the simulation model. The bending and contact strength of the spiral bevel gears and the bending strength of the planetary gear set showed a safety factor of 1 or more. However, the contact strength of the planetary gear set showed a safety factor of 0.92. Conservative results were derived by performing the analysis under the rated load condition of the motor. However, the ratio of the equivalent torque to the rated torque of the motor was 45% or less, hence, it was determined that no difficulties should arise regarding the durability of the axle.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.129-139
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• 2018

The Discrete Element Method (DEM) has been widely used in granular material researches. Especially, if material has a large deformation, such as ground, it can be a useful method to analyze. In this study, to simulate ground formations, DEM was used. The main purpose of DEM analysis was to investigate the numerical model which can predict the TBM performance by simulating excavating procedure. The selected EPB TBM has a 7.73 m of diameter and six spokes. And two pre-defined excavation conditions with the different rotation speeds per minute (RPM) of the cutterhead was applied. In the modeled cutterhead, the open ratio of cutterhead was 21.31% and number of cutters (including disc cutter and cutter bit) was 219. From the results, reaction forces and resistant torques at the cutterhead face and cutting tools, were measured and compared. Additionally the muck discharge rate and accumulated muck discharge by the screw auger were evaluated.

• Journal of KIBIM
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• v.10 no.3
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• pp.1-11
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• 2020

The introduction of BIM technology is expanding not only in the field of design and construction, but also in the maintenance and use stage. In particular, researchers are looking to build a smart facility management system that integrates advanced IT technology and BIM. This study proposes the parts to be used and added to the BIM information, focusing on information generated and exchanged in the application case that is an issue during the current facility maintenance work by introducing the smart facility management technology and its use cases. The effectiveness of this proposal is compared with the scenario in which BIM-based facility safety management is applied and the current business scenario. In conclusion, the requirements for smart facility management are analyzed, and linkable parts between facility management tasks and BIM data that should be reflected in the facility management system are presented. In the maintenance phase, through the use case scenario, the facility management phase is subdivided according to the characteristics and contents of the work. In addition, information about the facilities required for each task is specified. Furthermore, it is examined whether BIM data and IT information can be linked with existing facility management systems. It is a process and guideline that can be provided to practitioners who want to introduce BIM and smart technology to facility management. It can define the required data items and levels according to the required information step by step based on the maintenance case.

• Smart Structures and Systems
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• v.26 no.3
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• pp.319-329
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• 2020

Structural damage to an arch dam is often of major concern and must be evaluated for probable rehabilitation to ensure safe, regular, normal operation. This evaluation is crucial to prevent any catastrophic or failure consequences for the life time of the dam. If specific major damage such as a large crack occurs to the dam body, the assessments will be necessary to determine the current level of safety and predict the resistance of the structure to various future loading such as earthquakes, etc. This study investigates the behavior of an arch dam cracked due to water pressure. Safety factors (SFs), of shear and compressive tractions were calculated at the surfaces of the contraction joints and the cracks. The results indicated that for cracking with an extension depth of half the thickness of the dam body, for both cases of penetration and non-penetration of water load into the cracks, SFs only slightly reduces. However, in case of increasing the depth of crack extension into the entire thickness of the dam body, the friction angle of the cracked surface is crucial; however, if it reduces, the normal loading SFs of stresses and joints tractions reduce significantly.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.754-760
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• 2008

For monitoring of railway structures, optical fiber sensors are very convenient. The fiber sensors are very small and do not disturb the structural properties. They also have several merits such as electro-magnetic immunity, long signal transmission, good accuracy and multiplicity of one sensor line. Strain measurement technologies with fiber optic sensors have been investigated as a part of smart structure. In this paper, we investigated the possibilities of fiber optic sensor application to the monitoring of railway structures. We expect that the fiber optic sensors have much less noises than electrical strain gauges because of electro-magnetic immunity while railways operate electric power of 22000 volts. Fiber optic sensors showed good durability and long term stability for continuous monitoring of the railway structures as well as good response to the structural behaviors during construction.

• Journal of Drive and Control
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• v.17 no.4
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• pp.152-159
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• 2020

This study reviews the rear or tag axle steering system's concepts and technology applied to commercial vehicles. Most commercial vehicles are large in size with more than two axles. Maneuvering them around tight corners, narrow roads, and spaces is a difficult job if only the front axle is steerable. Furthermore, wear and tear in tires will increase as turn angle and number of axles are increased. This problem can be solved using rear axle steering technology that is being used in commercial vehicles nowadays. Rear axle steering system technology uses a cylinder mounted on one of rear axles called a steering cylinder. Cylinder control is the primary objective of the real axle steering system. There are two types of such steering mechanisms. One uses master and slave cylinder concept while the other concept is relatively new. It goes by the name of smart axle, self-steered axle, or smart steering axle driven independently from the front wheel steering. All these different types of steering mechanisms are discussed in this study with detailed description, advantages, disadvantages, and safety considerations.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.830-832
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• 2022

최근 산업 재해 중 업종별 사고 사망자 수가 1 위인 건설 산업에서 안전관리자는 실질적인 현장관리와 사고 예방의 핵심 인력으로 그 수요가 증가하고 있다. 안전 관리 활동 수준과 재해율은 높은 상관관계에 있음에도 불구하고 적은 인력 및 과도한 서류 작업으로 인해 직무 스트레스 및 생산성 저하에 큰 영향을 미치며 이는 현장 업무 효율성 저하 원인으로 꼽힌다. 특히 중소규모 건설사는 대형 건설사에 비해 안전 관리 활동 수준 차이 조사 항목에서 대부분의 항목에서 열악하며 통합관리시스템 또한 보유하지 않는 경우가 많아 문제가 대두되고 있다. 본 논문에서는 건설사 규모와 관계없이 이용 가능한 스마트글래스(SmartGlasses)와 애플리케이션(Application)으로 현장업무의 프로세스 자동화 구현 및 통합안전 관리 시스템을 제안하여 서류작업의 간소화, 직무 스트레스 감소, 건설 안전 관리자의 생산성 및 안전성의 혁신적 향상에 공헌한다.

• Smart Media Journal
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• v.12 no.9
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• pp.124-133
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• 2023

Currently, Korea shares culture, economy, and society together as a member of the international community along with rapid economic growth. In particular, in the 2000s, the construction of local cultural performance halls has been promoted through efforts and methods for the development of local culture. As a result, many local governments built medium-sized or larger performance halls, and achieved both quantitative and qualitative effects by satisfying citizens and attracting visitors. However, this study aims to analyze the safety of the space used by many visitors at the same time and whether an effective evacuation plan is applied to frequent disasters and disaster situations in recent years.

• Korean Journal of Construction Engineering and Management
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• v.12 no.4
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• pp.106-116
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• 2011

It is very important to collect and manage labor information in the construction industry that is labor-intensive. Although research and cases that utilize RFID are increasing for more effective labor management, labor management is limited to the checking-in and -out information management at the entrance of a construction site due to high expense of an RFID reader. Labor and safety information is still managed based on the redundant process that is hand-written in a book and re-input of information by using a personnel-computer. Therefore, the objective of this paper is to develop more effective and efficient process for labor information record and management. This paper presents a prototype application that supports integrated labor information management by incorporating QR-code into RFID-based labor management system and verifies the application through a pilot test and comparison with the existing labor management syste.