• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.4 s.56
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• pp.148-158
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• 2009

Firstly the problems of existing foreign code concerning wheel load distribution factor for skew box girder bridges have been examined, and the main parameters which have effects on wheel load distribution factors are evaluated in this study. Further finite element analyses on various skew steel box girder bridges are carried out. Based on the analysis results, formulas to determine wheel load distribution factors are proposed using multiple regression analysis. It is found when using the proposed formulas in this study weak points of existing specifications could be improved and also time spent at structural analysis should be saved a lot, so that the validity and practicality could be verified.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.508-512
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• 2015

Carbon emission calculation guidelines provided by the Korean Ministry of Land, Infrastructure and Transportation (MOLIT) and existing environmental load assessment studies have suggested a method for estimating based on the volume determined after the design development. Therefore they are not being helpful in the decision making of the environmental economics of road facilities in the planning stage in which specific information on construction output volume is lacking. Based on literature analysis of existing studies and consultation from a group of construction environmental professionals, 12 types of property information considered to be related to environmental load were selected from an inventory of information that will be available in the road planning stage. In addition, multiple regression analysis was performed based on the environmental load computed through the life cycle assessment (LCA) of 40 national highway project cases of Korea to deduce five impact factors of environmental load in the road facilities planning stage.

• Ocean Systems Engineering
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• v.6 no.2
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• pp.191-201
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• 2016

Stern bearing is a key component of marine propulsion plant. Its environment is diverse, working condition changeable, and condition severe, so that stern bearing load is of strong time variability, which directly affects the safety and reliability of the system and the normal navigation of ships. In this paper, three affecting factors of the stern bearing load such as hull deformation, propeller hydrodynamic vertical force and bearing wear are calculated and characterized by random theory. The uncertainty mathematical model of stern bearing load is established to research the relationships between factors and uncertainty load of stern bearing. The validity of calculation mathematical model and results is verified by examples and experiment yet. Therefore, the research on the uncertainty load of stern bearing has important theoretical significance and engineering practical value.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.377-379
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• 2002

This paper provides a new approach for the load-focused transmission marginal loss factors(MLF). It can be widely applied to power system operations and pricing mechanism in a competitive electricity market. The load-focused MLF is the ratio of required additional generation at a reference bus to the demand increments at a arbitrary bus. The new approach to determine the load-focused MLF was developed under some practically endurable assumptions. Although the suggested method is very similar to the conventional penaty factors in its concept, the method is more efficient than the existing heuristic method for the load-focused MLF. To show its effectiveness and efficiency, numerical test have been performed in IEEE 14-bus system.

• Journal of the korean Society of Automotive Engineers
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• v.4 no.2
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• pp.47-57
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• 1982

Smoke, Hydrocarbon and Garbon Monoxide emissions of concern in environmental pollution on AVDS-170-2D diesel engine were studied experimentally and past studies on emissions of diesel engine were investigate. Engine speed and load were considered as variable factors influencing the emissions. The test results of a multicylinder, direct injection and turblcharged 4 cycle diesel engine were compared with past studies. Both emission levels of experimental study and past studies were markedly influenced by engine operation factors. The results obtained in this study can be summarized as follows; 1) Smoke intensity is proportional to engine load and varies with engine speed. 2) Hydrocarbon and nitric oxides emissions vary with engine speed and load. 3) Garbon monoxide emission is insensitive to engine speed and varies with engine load.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1082-1087
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• 2006

Human factors still plays a significant role in railway accidents. The accidents often resulted from multiple causes of hardware failures and human errors. So to ensure the safety of railway operations, human error should be effectively prevented and managed. Among several factors influencing human performance, task load (or task complexity) is well known as a major contributor to human error. In order to reduce the potential of human error, a systematic analysis should be undertaken to evaluate task load and to reduce it by modifying task process and/or education&training. In this paper, we proposed a systematic framework for railway industry to perform task analysis and to evaluate task load, and applied it to KTX operational tasks. According to the application study, we identified 14 generic task types of KTX operation. And also this paper shows the quantitative task load of those generic tasks which were analyzed by NASA-TLX method.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.142-147
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• 2014

Finite element analysis along with DOE scheme has been performed to obtain robust design of connecting rod assembly. An analysis was conducted with five loading steps. Fatigue analysis was done using commercial software FEMFAT and fatigue safety factors at the interested regions such as shank area of small end and big end were calculated. 27 design cases using 3 factors with 3 levels are constructed by design of experiment. Each case is simulated to find the most influential factors. Response for this study, maximum Von-Mises stress, has been used to determine main factors of connecting rod assembly. Among the 3 factors, compression load affected the response greatly. However, bolt assembly load and width of shank flat area showed a little influence to the response. Interaction effects among factors considered did not occur. Connecting rod assembly considered in this study showed its sensitivity to the noise factor such as compression load rather than design factor such as width of flat shank area.

• Journal of the Korean Geotechnical Society
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• v.30 no.8
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• pp.25-37
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• 2014

In load and resistance factor design (LRFD) method, resistance factors are typically calibrated using resistance bias factors obtained from either only the data within ${\pm}2{\sigma}$ or the data except the tail values of an assumed probability distribution to increase the reliability of the database. However, the data selection approach has a shortcoming that any low-quality data inadvertently included in the database may not be removed. In this study, a data quality evaluation method, developed based on the quality of static load test results, the engineering characteristics of in-situ soil, and the dimension of aggregate piers, is proposed for use in constructing database. For the evaluation of the method, a total 65 static load test results collected from various literatures, including static load test reports, were analyzed. Depending on the quality of the database, the comparison between bias factors, coefficients of variation, and resistance factors showed that uncertainty in estimating bias factors can be reduced by using the proposed data quality evaluation method when constructing database.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.6
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• pp.70-76
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• 2013

The objective of the paper is to present the results of analytical and experimental studies dealing with dynamic load for continuous steel girder bridges due to normal truck traffic. Various bridge design codes specify dynamic load factor (defined as a fraction of static portion of live load) for short span structures at the level of about 0.3. However, there are not definite values specified for continuous brigdes. Therefore, it is an usual practice to use the code specified dynamic load factors for simple span bridges to continuous bridges without clear background. The field measurement results indicate that the actual dynamic load factors are less than 0.2 for a single truck, and less than 0.05 for two trucks side-by-side, regardless of positive and negative moment region.

• Journal of Biosystems Engineering
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• v.27 no.1
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• pp.1-10
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• 2002

This study was carried out to investigate experimentally the effect of three factors(dynamic load, inflation pressure and number of passes of tire) on soil compaction under the tire. The experiment were conducted with a 6.00R14 radial-ply tire for sandy loam soil using soil bin system. To evaluate the effect of three factors on soil compaction under the tire, the sinkage. density and volume of soil under the tire were measured fur the three levels of dynamic load(1.17kN, 2.35kN and 3.53kN), for the three levels of tire inflation pressure(103.42kPa, 206.84kPa and 413.67kPa), and for three different number of passes(1, 3 and 5). The results of this study can be summarized as follows : 1. As dynamic load, inflation pressure and number of passes of the tire increased, soil sinkage and density increased. and volume of soil decreased. Thus increase in dynamic load, inflation pressure and number of passes of the tire would increase soil compaction. 2. The effect of tire inflation pressure on sinkage. density and volume of soil under the tire was relatively less than that of the dynamic load. Therefore, it was concluded that dynamic load was more important factor affecting soil compaction in comparison to the inflation pressure of tire. 3. The effect of three different factors on sinkage, density and volume of soil decreased as the soil depth increase. Consequently, it was fecund that soil compaction at a shallow depth in soil was larger than that at deep place in soil.