• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.825-831
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• 2023

The propellers used for big ships have a large diameter and are very heavy. In order to apply a precise and safe work process to them, it is necessary to use an exclusive turning system. For this reason, various techniques are applied to produce them. However, workers' convenience and safety are not taken into consideration enough at production sites. Conventionally, these propellers are designed to be separated as their turning system is loaded and rotated by empty weight. Therefore, it is necessary to replace such a design. This study tries to find the weaknesses of the design and structure of a conventional propeller turning system for large ships, to verify structure integrity of a structure in structural analysis, and to devise a plan for designing a new type of turning system. In the basic concept design and structural analysis for the turning system used in the propeller finishing process for large ships, this study drew the following conclusions. It was possible to develop the work process of the turning system for the propeller finishing process used for large ships, to obtain the dimensions for exterior design through a basic design. Structural analysis was conducted to find the structure integrity of the turning system. As a result, in the rail installed to transfer a gantry, the maximum stress was about 45MPa, about 5.5 times lower than the yield strength 250MPa. Therefore, the turning system was judged to be safe structurally.

• Journal of the Korean Society of Safety
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• v.27 no.2
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• pp.72-77
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• 2012

There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as earth works, drainage works, pavement works, appurtenant works and etc based on accident examples and investigation on actual condition in roads construction work. In addition, the safety management system was developed to perform risk assessment of construction and use it for effective safety training for labor.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.73-80
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• 2011

There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as foundation, erection, pier, pier upper and etc based on accident examples and investigation on actual condition in bridges construction work. In addition, the safety management system was developed to perform risk assessment of construction and use it for effective safety training for labor.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.536-543
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• 2008

When the electric motor car was first introduced, an engineer, responsible for the work related to operation and a conductor for the announcement and management of entrances and the other services like as monitoring the passengers in the platforms used to take together the train for passengers' safe. As new technologies developed and the urban transit system had the automatic driving facilities, automatic door switch and broadcasting systems, to solve the financial problems, most subway systems introduced the one-man operation system. To curtail the operating expense through automatic control and operation for the economical efficiency, the crewless driving system was introduced abroad around 1970 on the light weight train and Japan started the crewless driving system in 2005, Germany started it in June 2008. We examine system requirements of the system and methods to construct safe systems that would be introduced, suitable for one-man operation system or crewless driving system through the surveys and analysis of driving state and the systems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.263-271
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• 2005

The most important point when we engage on waterway dredging work is supplying safe navigational passage to the vessels underway by narrowing dredge work area and removing submerged dangers. In order to meet this end it is neccessary to use auxiliary equipment for shifting actively and mooring and adopt automation of dredging work by integrating information on real time position, dredging depth, and work information. The danger with a spud control system in this study, by the way, is able to employed on continuous dredging work with the narrowest working area allowing wide and safe passages to vessels underway, by moving the dredger to the working zone with the spud controlled automatically. Furthermore, it has been improved definitely compared with the existing dredging proccess management system such that it shows the track of spud and working depth on the electronic navigation chart of window, together with the final outcome of dredging work. The test dredging work at the entrance of Busan North Port for system evaluation showed that actual working time available was twice of the one by the existing anchor system, and that it reduced 38% of time for preparation work and one man power.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.395-402
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• 2005

The most important point when we engage on waterway dredging work is supplying safe navigational passage to the vessels underway by narrowing dredge work area and removing submerged dangers. In order to meet this end it is necessary to use auxiliary equipment for shifting actively and mooring and adopt automation of dredging work by integrating information on real time position, dredging depth, and work information. The dredger with a spud control system in this study, by the way, is able to employed on continuous dredging work with the narrowest working area allowing wide and safe passages to vessels underway, by moving the dredger to the working zone with the spud controlled automatically. Furthermore, it has been improved definitely compared with the existing dredging process management system such that it shows the track of spud and working depth on the electronic navigation chart of window, together with the final outcome of dredging work. The test dredging work at the entrance of Busan North Port for system evaluation showed that actual working time available was twice of the one by the existing anchor system, and that it reduced $38\%$ of time for preparation work and one man power.

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.57-61
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• 2010

Formwork is a temporary structure that supports its weight and that of fresh concrete as well as construction live loads. Scaffoling is a temporary frame used to support people and material in the construction or repair of buildings and other large structures. It is usually a modular system of metal pipes, although it can be made out of other materials. Bamboo is still used in some Asian countries like China. The purpose of a working scaffold is to provide a safe place of work with safe access suitable for the work being done. In construction site, steel pipes are usually used as scaffolds. In this study, scaffolding systems which is changed according to sleeper and joist space were measured by buckling test. Buckling load of respective scaffolding system was analyzed by structural analysis program(MIDAS). Buckling load of scaffold with/without wall connection and footboard was got by test and structural analysis. According to these results，we know that scaffolding system of case 3 is suitable. Buckling load of scaffold with wall connection is higher than without wall connection. So wall connection is important in scaffoling systems. Footboard in the scaffolding systems is not effective against promotion of buckling load. Finally, the present study results will be used to design scaffolding systems safely in the construction sites.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.768-769
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• 2016

To prevent occupational disasters and build a pleasant work environment, it is necessary to develop a monitoring system to keep operators safe from the hazards. A variety of practical studies must be performed on application services designed to freely provide context-aware monitoring services in USN environments. This paper proposes a system in which work environment monitoring information can be monitored using a mobile phone and inference engine. The structure of a mobile work environment monitoring system is designed first. The proposed system is consisted of data manager, inference engine, database, and application knowledge base.

• Journal of the Korean Society of Safety
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• v.14 no.1
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• pp.158-166
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• 1999

Due to the work characteristics of shipyard industry, subcontractors are essential and employees of them consist of 25% of the total employee. Problems of their safety management are as follows; - obscurity of safety management responsibility - flimsiness of subcontractor's safety awareness - absence of ability to develop safety techniques and to provide safety equipments - lack of opportunity of safety education The purpose of this study is modelling safety management system of shipyard industry subcontractors to reduce industrial accidents by employees of subcontractors. A phased model contained organization and work responsibility of related departments, safety management planning and evaluation system, safe work supporting system, safety education supporting system.

• Nuclear Engineering and Technology
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• v.50 no.6
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• pp.860-868
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• 2018

This article presents a new design of earthquake instrumentation that is suitable for quick decision-making after the seismic event at the nuclear power plant (NPP). The main objective of this work is to ensure more availability of the NPP by expediting walk-down period when the seismic wave is incident. In general, the decision-making to restart the NPP after the seismic event requires more than 1 month if an earthquake exceeds operating basis earthquake level. It affects to the plant availability significantly. Unnecessary shutdown can be skipped through quick assessments of operating basis earthquake, safe shutdown earthquake events, and damage status to structure, system, and components. Multidecision parameters such as cumulative absolute velocity, peak ground acceleration, Modified Mercalli Intensity Scale, floor response spectrum, and cumulative fatigue are discussed. The implementation scope on the field-programmable gate array platform of this work is limited to cumulative absolute velocity, peak ground acceleration, and Modified Mercalli Intensity. It can ensure better availability of the plant through integrated decision-making process by automatic assessment of NPP structure, system, and components.