• Journal of the Korean Society of Safety
• /
• v.1 no.1
• /
• pp.51-59
• /
• 1986

This study was conducted to analyse the exact causes of occupational accidents in Korean construction industry and to contribute to the accident prevention programs. The results and conclusions of the field survey are as follows ： 1) The accidents caused by hazardous conditions are 96 percent, and those by unsafe acts are 97.3 percent. The accidents caused simultaneously by two categories are nore than 96 percent. 2) The injured workers who were employed less than 3 months are 71.1 percent. Safety training for newly recruited workers should be required. 3) More than 40 percent of all accidents were occurred in the morning and more than 30 percent were in summer. Required caution should be paid for the time and season. 4) Fracture, cut/laceration/puncture and multiple injuries in the lower extremeties, upper entremeties and head as well as many kinds of injuries by the fall from elevation mainly occurred. Safety. shoes, safety gloves, safety helmets, safety glasses, face shields and safity belts should be used 5) As the sources of injuries, each of building/structure and materials is one third of all sources, and machinery is a quarter. 6) The use of hazardous methods/procedures, defects of agencies and inadequate guarding of builing/structure, materials' and machinery mainly caused the accident types, such as s truck by, struck against, fall from elevation, and fall on same level. Such a hazardous conditiion should not be used and be correctet 7) The unsafe acts, such as improper use of hands or body parts, the operation or working at unsafe speed and improper use of equipment mainly caused accidents. Safety training for the control of such a unsafe acts should be strengthened.

• Steel and Composite Structures
• /
• v.46 no.3
• /
• pp.435-449
• /
• 2023

Time domain method and frequency domain method are commonly used in the current fatigue life calculation theory. The time domain method has complicated procedures and needs a large amount of calculation, while the frequency domain method has poor applicability to different materials and different spectrum, and improper selection of spectrum model will lead to large errors. Considering that artificial neural network has strong ability of nonlinear mapping and generalization, this paper applied this technique to random fatigue life prediction, and the effect of average stress was taken into account, thereby achieving more accurate prediction result of random fatigue life.

• Language and Information
• /
• v.13 no.1
• /
• pp.127-143
• /
• 2009

Tough-construction is, undoubtedly, one of the most puzzling syntactic problems in the history of transformational grammar. Various approaches have been proposed including Deletion approaches (Akmajian, 1972; Lasnik and Fiengo, 1974) and movement approaches. Among the movement approaches, Chomsky (1977; 1981) argues for movement of null Operator, and Hornstein (2001) argues for a two-step movement equipped with Sideward movement. Most recently, Schueler (2004) and Hartman (2009) each have also argued for a kind of movement approach. With the development of the Minimalist syntax (Chomsky, 1995; Chomsky, 2000; Chomsky, 2001), tough-construction, an age old problem in the description of grammar, turns into another round toward to a more satisfactory answer. By examining the most recent competing analyses of tough-constructions, this paper defends and extends Schueler's (2004) analysis, rather than Hartman's (2009) two step movement approach. Furthermore, this paper proposes that tough-subject originates from the intermediate CP internal Spec-TopicP position rather than from the iterated CP layer (Authier, 1992). This approach has more descriptive power than it was originally argued for in Schueler (2004) and is a step closer toward Minimalism insofar as the conception of government is no longer utilized.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2007.11a
• /
• pp.455-458
• /
• 2007

With the government plan to introduce a post-sale system to the Korean real estate market quickly becoming a reality, reformation of the supervision policy under the current pre-sale system is expected. The current supervision policy, designed to enhance the quality of houses and to prevent improper construction, was reinforced through the 'residential construction promotion act' and has been further revised as the 'residential law'. At this current time, the introduction of a post-sale system is expected to affect all aspects of residential construction, from the planning stages to overall conditions regarding the actual construction. Therefore, this research will illustrate several changes in the supervision policy that are expected to arise from the introduction of the post-sale system, focusing on areas of the policy that are presumed to be the most affected. The research will highlight problems under the current system, analyze any domestic supervision restrictions that have been regulated for post-sales that are currently effective, and suggestion methods of improvement in construction supervision system through SWOT analysis.

• International Journal of Highway Engineering
• /
• v.19 no.4
• /
• pp.19-25
• /
• 2017

PURPOSES : In this paper, the flow of construction material was simulated using computational fluid dynamics in a 2D axisymmetric condition to evaluate the effect of initial or varying material properties on the final shape of a specimen. METHODS : The CFD model was verified by using a well-known analytical solution for a given test condition followed by performing a sensitivity analysis to evaluate the effect of material properties on the final shape of material. Varying dynamic viscosity and yield stress were also considered. RESULTS : The CFD model in a 2D axisymmetric condition agreed with the analytical solution for most yield stress conditions. Minor disagreements observed at high yield stress conditions indicate improper application of the pure shear assumption for the given material behavior. It was also observed that the variation of yield stress and dynamic viscosity during curing had a meaningful effect on the final shape of the specimen. CONCLUSIONS : It is concluded that CFD modeling in a 2D axisymmetric condition is good enough to evaluate fluidal characteristics of material. The model is able to consider varying yield stress and viscosity during curing. The 3D CFD-DEM coupled model may be required to consider the interaction of aggregates in fluid.

• Korean Journal of Construction Engineering and Management
• /
• v.10 no.5
• /
• pp.16-27
• /
• 2009

Recently construction companies expand position for apartment house in construction market because of house supply rate increase and its amount. In addition, because the focus of house sale market has moved to customer from supplier, the importance of defect management is being issued currently. However, current apartment defect management is not satisfied with customer's demand for the lack of business process management, management organization, information feedback, and readiness for defect in construction phase. To solve this problem, this study proposed business process management improvement model for defect management. Proposed improvement model make information feedback, defect management business quality improvement, and improper process improvement through integrating defect management and quality management. It is expected to contribute to customer's satisfaction improvement and reliance improvement for construction companies.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2008.11a
• /
• pp.694-697
• /
• 2008

A retaining wall system suitable for a construction project is selected on the basis of subsoil conditions. If the decision-maker selects an improper system, it has a negative effect on the cost and schedule of the construction project. There have been many studies related to the models and processes for selecting optimal retaining wall systems. However, engineers who are not familiar with formal analysis methods could not easily utilize the formal methods proposed by previous studies. In order to overcome this problem, we developed a web-based decision support system called Dr. Underground, which is both physically and technically easily accessible by engineers. Dr. Underground was developed based on a selection method developed from a precedent research project. It was developed using a server-side web language ASP.NET and MS Access as a database. Decision-makers can input data about the building's condition, construction site conditions and adjacent site conditions in this system. Based on the input data, Dr. Underground recommends an optimal retaining wall system for the inputted conditions and provides detail information on the system.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.1542-1549
• /
• 2009

The function of subgrade in the railway is to support track load on the subgrade as well as train load. Unlike the traditional railway, the uppermost subgrade layer in the Gyeongbu high speed railway was constructed as the reinforced road bed. The reinforced road bed comprises sub-ballast in the upper part and grade ballast in the lower part. The filling material such as soil and rocks in the subgrade can be settled by consolidation of original ground, compression due to self weight, plastic displacement due to train operation, and unequal settlement due to embankment material or improper compaction, therefore many efforts have been given for sufficient compaction and use of proper filling materials in the construction stage. The purpose of this study is to investigate the deformation state of subgrade in the Gyeongbu high speed railway. The investigation on the subgrade settlement was performed by choosing representative sections suspected to be settled based on the previous GPR test results and track maintenance history, measuring the settlement for some time period after installing settlement measuring instruments on and under the reinforced road bed. and analyzing the long-term subgrade settlement data from monitoring system which was installed at the construction stage of the high speed railway.

• Journal of the Korean Institute of Rural Architecture
• /
• v.12 no.4
• /
• pp.1-11
• /
• 2010

This study is a research examining reshaped pattern in the perspective of repairing parts and materials through repairing renovation of registered cultural properties constructed in modern times and results are as followings. Repairing construction of registered cultural properties of Jollanamdo according to parts is shown numerously in the order of roof, walls and windows, and mostly outworn as time passes on and leakage were the main cause of repair. Also when original shape was damaged by previous repair in the past, and this was another reason of repairing. It was surveyed that among the repairing job repair of damage occurred on the part of roofing area including water leakage, corrosion and damage of roofing material, and damage of groove channel were the most main cause of repair. Especially when roof leakage is occurred by outworn of roofing materials, this cause corrosion and damage of materials due to the damage of leakage parts and this cause repeating cycles of worse leakage again and again. Main repairing materials which deform the original shape of registered cultural properties were confirmed as copper plate used on the roof. Copper plate showing high frequency of application which replaces groove slate or cement roofing tile used on the roof before has high durability and anti-corrosion but it is considered improper material to recover original shape.

• The Mathematical Education
• /
• v.62 no.1
• /
• pp.1-21
• /
• 2023

The purpose of this study is to explore how the student, who interiorized three levels of units, constructed fractions as multipliers by analyzing her ways of conceiving improper fractions with three levels of units and coordinating two three-levels-of-units structures. Among the data collected from our teaching experiment with two 4th grade students meeting 13 times for three months, we focus on how Seyeon, one of the participating students, wrote numerical expressions in the form of "× fraction" for the given situations using her splitting operation for composite units. Given the importance of splitting operation for composite units for the construction of fractions as multipliers, implications for further research are discussed.