• Safety and Health at Work
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• v.15 no.1
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• pp.24-32
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• 2024

Background: Learning from incidents for accident prevention is a two-stage process, involving the investigation of past accidents to identify the causal factors, followed by the identification and implementation of remedial measures to address the identified causal factors. The focus of past research has been on the identification of causal factors, with limited focus on the identification and implementation of remedial measures. This research begins to contribute to this gap. The motivation for the research is twofold. First, previous analyses show the recurring nature of accidents within the Ghanaian mining industry, and the causal factors also remain the same. This raises questions on the nature and effectiveness of remedial measures identified to address the causes of past accidents. Secondly, without identifying and implementing remedial measures, the full benefits of accident investigations will not be achieved. Hence, this study aims to assess the nature of remedial measures proposed to address investigation causal factors. Method: The study adopted SMARTER from business studies with the addition of HMW (H - Hierarchical, M - Mapping, and W - Weighting of causal factors) to analyse the recommendations from 500 individual investigation reports across seven different mines in Ghana. Results: The individual and the work environment (79%) were mostly the focused during the search for causes, with limited focus on organisational factors (21%). Forty eight percentage of the recommendations were administrative, focussing on fixing the problem in the immediate affected area or department of the victim(s). Most recommendations (70.4%) were support activities that only enhance the effectiveness of control but do not prevent/mitigate the failure directly. Across all the mines, there was no focus on evaluating the performance of remedial measures after their implementation. Conclusion: Identifying sharp-end causes leads to proposing weak recommendations which fail to address latent organisational conditions. The study proposed a guide for effective planning and implementation of remedial actions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.430-436
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• 2018

Special railway vehicles for track maintenance are equipped with a tamping device that adjusts various track trajectories to reduce the vibration of rolling stock and improve ride quality during trains passing over a track. The development of a simulator that can confirm the error of the actual tamping work is important for reducing human error in the linearization of the track misalignment. In this study, to improve the reality and training effect of conventional 2D simulator, 3D simulator modeling was implemented for tamping work of special railway vehicles in virtual space. The problem of buffering during high screen quality of tamping work was solved using the Unwrap UVW mapping technique of a low polygon extracted from high quality polygon modeling. The human error in the training of the tamping work was detected by the principle of circle and square collision when the tamping tyne and the sleeper collided. In addition, vibration of the driving chair was generated at the same time as the collision, and the number of the sleeper strikes is displayed on the simulator exercise screen. Owing to the scattering of railway ballast protruding from the sleepers, which had a serious effect on the safety of the vehicle, the gravel bouncing effect of the tamping unit was applied.

• Journal of the Korean Institute of Rural Architecture
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• v.1 no.2
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• pp.83-96
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• 1999

The Buildings and facilities of municipal Councils of fundamental autonomous organization in various regions were made on the basis of its experiences in 1950s but lacked constructional sophistication and failed to comprehend their functions, resulting in several repairs and renovations after the dedications of the buildings. They also undermined the efficiencies of the worn and was a big drain on the budget of municipal councils. Furthermore, especially after the integration of rural and urban areas. Municipal councils in urban areas couldn't accommodate the increased staffs. Thereby, They used the established councils in the cities and countries and repaired and renovated other buildings of which were permitted as offices, decreasing the eligibility of the buildings for municipal councils. The poor constructional working conditions triggered new constructions of the buildings reserved only for municipal councils. The study finds out find out about the work of municipal councils and analyzes how the municipal council buildings are used as substitutional spaces, directing which way they should go in mapping out spaces. Resultantly, It becomes basic materials in constructing municipal buildings.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.6
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• pp.619-625
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• 2009

FastSLAM which uses the Rao-Blackwellized particle filter is one of the famous solutions to SLAM (Simultaneous Localization and Mapping) problem that estimates concurrently a robot's pose and surrounding environment. However, the particle depletion problem arises from the loss of the particle diversity in the resampling process of FastSLAM. Then, the performance of FastSLAM degenerates over the time. In this work, DIR (Density Information-based Resampling) technique is proposed to solve the particle depletion problem. First, the cluster is constructed based on the density of each particle, and the density of each cluster is computed. After that, the number of particles to be reserved in each cluster is determined using a linear method based on the distance between the highest density cluster and each cluster. Finally, the resampling process is performed by rejecting the particles which are not selected to be reserved in each cluster. The performance of the DIR proposed to solve the particle depletion problem in FastSLAM was verified in computer simulations, which significantly reduced both the RMS position error and the feature error.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.473-494
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• 2020

To provide a guaranteed Quality of Service (QoS) to real-time traffic in High-Speed Downlink Packet Access (HSDPA) core network, we proposed an enhanced mechanism. For an enhanced QoS, a Class-Based Low Latency Fair Queueing (CBLLFQ) packet scheduling algorithm is introduced in this work. Packet classification, metering, queuing, and scheduling using differentiated services (DiffServ) environment was the points in focus. To classify different types of real-time voice and multimedia traffic, the QoS provisioning mechanisms use different DiffServ code points (DSCP).The proposed algorithm is based on traffic classes which efficiently require the guarantee of services and specified level of fairness. In CBLLFQ, a mapping criterion and an efficient queuing mechanism for voice, video and other traffic in separate queues are used. It is proved, that the algorithm enhances the throughput and fairness along with a reduction in the delay and packet loss factors for smooth and worst traffic conditions. The results calculated through simulation show that the proposed calculations meet the QoS prerequisites efficiently.

• Journal of Mechanical Science and Technology
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• v.16 no.12
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• pp.1652-1663
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• 2002

It is desirable to perform nondestructive evaluation to assess material properties and part homogeneity because manufacturing of carbon/carbon (C/C) composites requires complicated and costly processes. In this work several ultrasonic techniques were applied to carbon/carbon composites for the evaluation of spatial variations in material properties that are attributable to the manufacturing process. In a large carbon/carbon composite manufactured by chemical vapor infiltration (CVI) method, the spatial variation of ultrasonic velocity was measured and found to be consistent with the densification behavior in CVI process in order to increase the density of C/C composites. Ultrasonic velocity and attenuation depend on a density variation of materials. Low frequency through-transmission scans based on both amplitude and time-of-flight of the ultrasonic pulse were used for mapping out the material property inhomogeneity These results were compared with that obtained by dry-coupling ultrasonics. Pulse-echo C-scans was used to image near-surface material property anomalies such as the placement of spacers between disks during CVI. Also, optical micrograph had been examined on the surface of C/C composites using a destructive way.

• Journal of Korea Multimedia Society
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• v.17 no.2
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• pp.257-265
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• 2014

3 dimensional stereoscopic is attracting new attention as it simulates human eye and related hardware advances. However, 3 dimensional stereoscopic requires more time and effort than 2D movie because it uses 2 cameras or 2 lenses. This study analyzed the merits and demerits of the system producing rider movie using 3 dimensional stereoscopic shooting techniques and searched a way to produce better 3 dimensional stereoscopic rider movie which meets the producing intention by applying elements required to create effective 3 dimensional stereoscopic effect. According to the study result, a light-weight integrated system was effective to create 3 dimensional stereoscopic rider movie because of its genre characteristic. In the post-production of the work, location shooting considered of time re-mapping, color correction and graphic element addition was required.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.11 no.2
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• pp.27-34
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• 1993

The construction of the accurate, economic topographic information for a sorts of work and a base facilities of country is one of the very important subjects. In this paper, Global network which include south KOREA and Regional network which include Chung-Nam/Chung-Buk provinces were designed, obtained WGS84 coordinates of control points in networks by GPS. The coefficients of transformation between WGS84 coordinates and Bessel coordinates in consideration of geoid undulations was derived by 7-parameter method. Also, the efficiency of 7-parameter method was proved through successful application of T.M. and U.T.M projection for the precise mapping, and the effectiveness of the aquisition of three dimensional topographic information by GPS was suggested.

• Journal of Forest and Environmental Science
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• v.30 no.1
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• pp.15-29
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• 2014

This article discusses the state of a community forestry program in a protection forest in Indonesia, which has been running for almost two decades. We found that the program did not achieve its objective mainly because of frequent changes in regulations. There are also activities such as: measuring and mapping working area boundaries, drawing up a work plan, planting, maintenance and security, paying royalties to those who harvest forest resources, and submitting annual reports on land use to the district government head, which have not worked as expected. We also found that the major incentives for local people to participate in the program are getting certificates of management and the program's effectiveness in minimizing land-use conflicts. Participants perceived that their major role on the program is to follow farmer-group directives or government rules. To achieve the program's purposes, farmer groups need technical assistance related to protection-forest management and opportunities for financing.

• Journal of IKEEE
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• v.11 no.4
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• pp.219-226
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• 2007

An efficient block based two-layer JPEG encoding algorithm is proposed to compress high dynamic range (HDR) images in this work. The proposed algorithm separates an input HDR image into a tone-mapped low dynamic range (LDR) image and a ratio image, which represents the quotients of the original HDR pixels divided by the tone-mapped LDR pixels. Then, the tone-mapped LDR image is compressed using the standard JPEG scheme to preserve backward compatibility and the ratio image is encoded to minimize a cost function that models the perception of each block with different quantization parameters in the human visual system (HVS). Simulation results show that the proposed algorithm provides better performance than the conventional method, which encodes the ratio image without any prior information of blocks.