• 한국안전학회지
• /
• 제28권3호
• /
• pp.11-17
• /
• 2013

Forensic Engineering is the area covering the investigation of products, structures that fail to perform or do not function as intended, causing personal injury or damage to property. To investigate the mobile crane's overturn accident in terms of the forensic engineering, in this study, we identified the accident mobile crane's position and posture before accident by the analysis of the trace resulted by the contact between the outrigger and the ground, and the accident remodeling has been performed using CATIA modeling program in the basis of the accident mobile crane's position and posture information. The accident analysis has been performed by comparing this accident remodeling and the crane's specification, the table of the allowance load about the boom's length and the working radius. Through these studies, the safety accident that may occur in mobile crane can be minimized by performing specialized and systematic investigation of the accident cause in terms of the forensic engineering.

• Industrial Engineering and Management Systems
• /
• 제13권2호
• /
• pp.172-184
• /
• 2014

Economic growth with rising household income has put more vehicles on the roads worsening traffic congestion, road accidents, and air and noise pollution. This situation is further aggravated by the potential working population who choose to drive to work instead of taking public transportation. Public bus transport (PBT) plays an important role in alleviating these problems. PBT is underutilized in Malaysia, and there is an opportunity to increase ridership without substantial investment. Therefore, this study was conducted to investigate the factors that influence the use of PBT in Malaysia. The data were collected using structured questionnaires from 400 respondents. The results of the analysis show that the twin factors consisting of perceived satisfaction of and perceived importance by users towards safety and comfort of facilities and services offered by PBT are significantly related to intention to use those services. The satisfaction of availability of season tickets, the importance of reliability of bus schedule and time table, and the importance of ticket pricing are also significant. By providing insights for both public bus operators and the government, this paper contributes to mitigate the underutilization of PBT in Malaysia and the consequences of putting more vehicles on the roads. From the theory perspective, this paper also contributes by extending the theory of reasoned-action to transportation studies.

• 한국정보통신학회논문지
• /
• 제8권3호
• /
• pp.586-597
• /
• 2004

MAC (Medium Access Control) protocol is necessary for a OLT (Optical Line Termination) to allocate bandwidth to ONUs (Optical Network Units) dynamically in ATM PON (Passive Optical Network) operated in a kind of optical subscriber network having tree topology. The OLT collect information about ONUs and provide all permission with each ONU effectively by means of MAC protocol. Major functions of MAC protocol are composed of the algorism for distributing permission demanded by a ONU dynamically and allocation all permission used in APON properly. Sometimes MAC get to be a element of limiting the whole operation speed and occupy a most frequent operation part of the TC (Transmission Convergence) function module so it have to be designed to guarantee the best quality for each traffic. This paper introduce the way of implementation of a algorism which satisfy all of the upper renditions. This MAC algorism allocate bandwidth according to a number of working ONU and the information of the queue length dynamically and distribute permission for same interval to minimize delay variation of each ONU cell. MAC scheduler for the dynamic bandwidth allocation which is introduced in this paper has look-up table structure that makes programming possible. This structure is very suitable for implementation and operated in high speed because it require very simple and small chip size.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 추계학술대회논문집
• /
• pp.176-179
• /
• 2005

To control the vibration transmitted to the precision instruments from ground has always been of great interest among the researchers. This paper proposes a single axis vibration isolation system which can be used as a module far a table top six axis isolator for highly precise measurement and actuation system. The combined active-passive isolation principle is used for vertical vibration isolation by mounting the instrument on a passively damped isolation system made of Elastomer along with the active stage in series which consists of very stiff piezo actuator. The active stage works in combination with the passive stage for working as a very low frequency vibration attenuator. The active stage is isolated from the payload disturbance through the Passive stage and thus modularity in control is achieved. This made the control algorithm much easier as it does not need to be tuned to specific payload.

• 한국식품조리과학회지
• /
• 제29권1호
• /
• pp.63-71
• /
• 2013

The purpose of this study was to analyze the gap between importance and performance in perceived sanitation management for general hospital foodservice operations. Data were collected through surveys given to 168 hospital dietitians in the Seoul-Incheon, Gyeonggi-do, Daegu, and North Gyeongsang province. The 65 questionnaires from total questionnaires were usable and the response rate was 38.7%. All statistical analyses were conducted using the SPSS package program (version 20.0) for t-test, ANOVA, and importance-performance analysis (IPA). According to the importance and performance analysis for 26 items, the importance score was significantly higher than the performance score for 22 items. In addition, the results of IPA showed the following areas as improvement priorities: handling foods on working table and management of distribution temperature. In conclusion, the performance level of prerequisite programs applying to the hospital foodservice needs improvement, especially cross-contamination prevention and temperature control for distribution. Additionally dietitians should be educated about sanitation management items that perceived to be less important than the others.

• International Journal of Internet, Broadcasting and Communication
• /
• 제13권4호
• /
• pp.121-128
• /
• 2021

In order to design a real time big data collection and analysis system of manufacturing data in a smart factory, it is important to establish an appropriate wired/wireless communication system and protocol. This paper introduces the latest communication protocol, OPC-UA (Open Platform Communication Unified Architecture) based client/server function, applied user interface technology to configure a network for real-time data collection through IoT Integration. Then, Database is designed in MES (Manufacturing Execution System) based on the analysis table that reflects the user's requirements among the data extracted from the new cutting process automation process, bush inner diameter indentation measurement system and tool monitoring/inspection system. In summary, big data analysis system introduced in this paper performs SPC (statistical Process Control) analysis and visualization analysis with interface of OPC-UA-based wired/wireless communication. Through AI learning modeling with XGBoost (eXtream Gradient Boosting) and LR (Linear Regression) algorithm, quality and visualization analysis is carried out the storage and connection to the cloud.

• 대한건축학회논문집:구조계
• /
• 제34권4호
• /
• pp.65-74
• /
• 2018

The primary objective of this study is to develop a conceptual design of automated pothole patching machine that improves the conventional work in safety, quality, and productivity. For this, the following research works are conducted sequentially; 1)literature review, 2)selection of element technology for conceptual design, 3)deduction of work process and conceptual design, 4)life cycle cost analysis of the conceptual design. As a result, X-Y table telescopic manipulator, pothole patching end effector, realtime pothole recognizer, 3D pothole volume profiler, automated pothole patching machine controller are selected as core technologies. Furthermore, a conceptual design and working process of an automated pothole patching machine are developed based on the core technologies. According to the life cycle cost analysis result, the cost of the automated method was 38.3% less than that of the conventional method, and the economic efficiency was also superior(ROR 77.1%, Break-even Point 23.8month). It is expected that the application range and impact on the construction industry will be enormous due to the increasing trend of road maintenance market.

• 한국기계가공학회지
• /
• 제20권6호
• /
• pp.10-16
• /
• 2021

Drilling is a crucial process that takes up a significant amount of weight during machining operations. In addition, drill tip-type tools and related operations have been developed for manufacturing industries to achieve economic efficiency. In this study, SM45C carbon steel, widely used for machine structures, was utilized as the working material after quenching and tempering. Insert-tip types of carbide tools, such as TiN and TiAlN, were used as tool materials. Drilling conditions such as the spindle revolution, feed rate, step of cut, and tool diameter were used to measure roughness, roundness, and straightness using the orthogonal array table statistical method. The surface roughness, roundness, and straightness characteristics based on the conditions were analyzed using ANOVA. The results showed that the spindle speed and feed rate were the main factors influencing carbide insert-tip drilling under the same conditions as the experimental conditions.

• Smart Structures and Systems
• /
• 제31권5호
• /
• pp.455-467
• /
• 2023

Impact damper is a passive damping system that controls undesirable vibration with mass block impacting with stops fixed to the excited structure, introducing momentum exchange and energy dissipation. However, harmful momentum exchange may occur in the random excitation increasing structural response. Based on the mechanism of impact damping system, a semi-active impact damper (SAID) with controllable impact timing as well as a semi-active control strategy is proposed to enhance the seismic performance of engineering structures in this paper. Comparative experimental studies were conducted to investigate the damping performances of the passive impact damper and SAID. The extreme working conditions for SAID were also discussed and approaches to enhance the damping effect under high-intensity excitations were proposed. A numerical simulation model of SAID attached to a frame structure was established to further explore the damping mechanism. The experimental and numerical results show that the SAID has better control effect than the traditional passive impact damper and can effectively broaden the damping frequency band. The parametric studies illustrate the mass ratio and impact damping ratio of SAID can significantly influence the vibration control effect by affecting the impact force.

• 패션비즈니스
• /
• 제13권6호
• /
• pp.61-75
• /
• 2009

The objective of this research is to the enhance the color function of work clothing : to research and analyze the hue and tone of work clothing colors to be used for machinery and heavy industries in national industrial complexes, Through this research, the color using problems which related with safety workers will be revealed. For this project, total 42 sets of work suits were sampled from 12 different companies in the machinery and construction industries in the national industrial complexes of Gyeongsang Namdo Province and 16 sets of work suits currently being sold in the market. The collected work suits samples were classified according to item types and design. Color measurements were taken thus: After calibration according to ASTM D1729 specifications of standardized configuration settings to match standardized luminous source D65(Daylight 6500K) in color cabinet BOTECK SuperLight-VI, the RGB values of the work suits were calculated using PANTONE Color Cue TX. The RGB values of the colors thus derived were converted into V/C values using the Munsell Conversion 9.0.6 and analyzed with Munsell's 10-color system and PCCS. The results were presented according to Munsell's color wheel and color and brightness distributions were expressed in table form, as well as presented as a tone map. Following analysis, color hue distribution was found to be concentrated around PB, and brightness distribution toward the low end and mid range of the scale. Saturation values were distributed mostly around the low end of the scale. Following color tone analysis according to PCCS, it became apparent that colors were mainly distributed around dkg, ltg, and g, at low- and mid-brightness and low-saturation. Therefore, it may be concluded that colors used in work suits in the machinery and heavy industries are mainly cool colors, at low- and mid-brightness and low saturation. It is conjectured that such colors were applied uniformly in the workplace in order to serve certain functions, such as concealment of stains and contamination. Therefore, it follows that the utilization of colors, among other functions served by working clothings, must be taken into consideration in order to enhance safety and efficiency.