• Journal of Advanced Marine Engineering and Technology
• /
• v.10 no.2
• /
• pp.146-155
• /
• 1986

Until recently, the calculation of torsional vibration for the marine diesel engine shafting has been performed only for vibratory stresses of resonant points and vibratory stresses for other engine speeds are determined by the estimation. With the advent of energy-saving engines which have a long stroke and a small number of cylinders, the first major critical torsional vibration of the propulsion shaft appears ordinarily near the MCR speed of engine and the flank of its vibratory stress exceeds now and then the limit stress defined by the rules of Classification Society. In order to know the above condition in the design stage of propulsion shafting, it is necessary to calculate the forced torsional vibration with the damping of propulsion shafting for all orders and to synthesize its calculated results according to their phase angles. In this study, the forced torsional vibrations with the damping of propulsion shafting are calculated for several orders by mechanical impedance method, and their results are synthesized. A computer program for above calculations are developed and some test-runs of the developed program are performed for propulsion shaftings of actual ships. The results of calculations are compared with measured values and also with those of the modal analysis method. They show fairly good agreements and the developed program is checked up on its reliability.

• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.9
• /
• pp.903-910
• /
• 2015

The purpose of this research is to develop a full-spectral fatigue analysis program, based on rigid-body ship motion analysis, in order to perform a full-spectral fatigue analysis that considers hydroelasticity effects. To gain credibility, fatigue analysis results of two ship types, performed by the developed program, were compared with those of a classification society, and it was found that both are identical. Full-spectral fatigue analysis considering hydroelasticity effects would be developed in further studies by including flexible-body ship motion analysis results and by supplementing the developed program with a wide-band fatigue damage model.

• Journal of Biosystems Engineering
• /
• v.40 no.3
• /
• pp.232-237
• /
• 2015

Purpose: In Korea, wheat is dried using circulating cross-flow grain dryers. However, there is no research on wheat drying which can be utilized for the dryers. Therefore, this study developed and evaluated a simulation of the circulating cross-flow dryer, and examined the effects of various factors on drying performance. Methods: The simulation program was developed using drying models and was evaluated against wheat-drying experiments with a dryer having a 30-ton capacity. The influence of drying temperature, air volume, and grain falling rate on drying performance were examined through the simulation. Results: The experimental results validated the simulation program by showing the same root mean square error (RMSE) for moisture content (0.286%) and drying rate (0.056%/h) in both the experimental data and the simulation values. The appropriate wheat-drying parameter values, considering drying conditions, were determined to be $50^{\circ}C$ for drying temperature, $500m^3/min$ for air volume, and a grain falling rate of $36.0m^3/h$. Conclusions: The developed simulation program for circulating cross-flow dryers analyzed the influences of performance factors such as drying temperature, air volume, and falling rate on drying performance.

• The Mathematical Education
• /
• v.53 no.3
• /
• pp.357-381
• /
• 2014

This study analyzed the cases of three teacher communities participating in an innovative professional development program and clarified the characteristics and the process of lessons for mathematics-oriented convergence that were developed and applied during the program. Each of the teacher communities designed and implemented lessons according to the context of each community and the concept of lessons for mathematics-oriented convergence were developed and refined. The lessons developed by the three teacher communities were characterized as convergence problem posing lessons using technology, convergence of various subject content focused on mathematical concepts through team teaching, and convergence lessons according to students' achievement levels. The program contributed to teacher community activities by proving sustainable professional development in the area of convergence education, a connection between the content of their professional development and the context of the field, and opportunities for active participation in the process of developing and implementing the convergence lessons.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.47
• /
• pp.263-298
• /
• 2010

The global trading system is vulnerable to terrorist exploitation while the international trade is an essential element for the economic development. Customs has a unique role in the international trade to provide increased security while ensuring facilitation of the legitimate flow of goods and the role of Customs has become more and more indispensable these days. In response to this trend, the World Customs Organization(WCO), the organization of more than 170 Customs administrations all over the world, adopted an international framework("SAFE Framework") in 2005, which includes the Authorized Economic Operator(AEO) concept, whereby a party involved in the international movement of goods would be approved by Customs as complying with the supply chain security standards, and given benefits, such as simplified Customs procedure and less Customs intervention. In this stream, the Japanese government has developed and promoted AEO Program in close cooperation with the business sector, aiming at ensuring security while facilitating legitimate trade. For that purpose, Japan Customs, as a main entity in the field of international trade, has developed comprehensive AEO program with combination of programs for importers, exporters, warehouse operators, Customs brokers and logistics operators, such as forwarders and carriers, which are consistent with the "SAFE Framework" developed by the WCO. The purpose of this paper aims to analyse the introduction plans of AEO program for the trade security and trade facilitation with Japanese AEO system.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.48 no.1
• /
• pp.27-38
• /
• 2006

In this study, we developed a program to estimate discharge efficiently considering major hydraulic characteristic including water level, river bed, water slope and roughness coefficient in a natural river. Stream discharge was measured at Gongju gauge station located in the down stream of the Daechung Dam during normal and dry seasons from 2003 to 2004. The developed model was compared with the results from the existing rating curve at T/M gage stations, and was used for runoff analyses. Evaluating the developed river discharge estimation program, it was applied during 1983-2004 that base flow separation method and RRFS (Rainfall Runoff Forecasting System) which is based on SSARR (Streamflow Synthesis And Resevoir Regulation). The result presents the stage-discharge curve creator range at the Gong-ju is overestimated by approximately $10-20\%$, especially at the low stage. It is attributed to the hydraulic characteristics at the study. The discharge simulated by the RRFS and base flow separation, which is calibrated using the measurement at the early spring and late fall season during relatively d]v season, shows the least errors. The coefficient of roughness at Gongju station varied with the high and low water level.

• Computers and Concrete
• /
• v.4 no.5
• /
• pp.331-346
• /
• 2007

A computer program was developed to analyze the non-linear, cyclic flexural performance of reinforced concrete structural members under various types of loading paths including non-sequential variations in axial load. This performance is significantly affected by the loading history. Different monotonic material models as well as hysteresis rules for confined and unconfined concrete and steel, some developed and calibrated against test results on material samples, were implemented in a fiber-based moment-curvature and in turn force-deflection analysis. One of the assumptions on curvature distribution along the member was based on a method developed to address the variation of the plastic hinge length as a result of loading pattern. Functionality of the program was verified by reproduction of analytical results obtained by others for several cases, and accuracy of the analytical process and the implemented models were evaluated against the experimental results from large-scale reinforced concrete columns tested under the analyzed loading cases. While the program can be used to predict the response of a member under a certain loading pattern, it can also be used to examine various analytical models and methods or refine a custom material model against test data.

• Steel and Composite Structures
• /
• v.44 no.5
• /
• pp.603-617
• /
• 2022

Structural design, in general, is developed through trial and error technique which is guided by standards criteria and based on the intuition and experience of the engineer, a context that leads to structural over-dimensioning, with uneconomic solutions. Aiming to find the optimal design, structural optimization methods have been developed to find a balance between cost, structural safety, and material performance. These methods have become a great opportunity in the steel structural engineering domain since they have as their main purpose is weight minimization, a factor directly correlated to the real cost of the structure. Assuming an objective function of minimum weight with stress and displacement constraints provided by Brazilian standards, the present research proposes the sizing optimization and combined approach of sizing and shape optimization, through a software developed to implement the Simulated Annealing metaheuristic algorithm. Therefore, two steel plane frame layouts, each admitting four typical truss geometries, were proposed in order to expose the difference between the optimal solutions. The assessment of the optimal solutions indicates a notable weight reduction, especially in sizing and shape optimization combination, in which the quantity of design variables is increased along with the search space, improving the efficiency of the optimal solutions achieved.

• Journal of Agricultural Extension & Community Development
• /
• v.19 no.2
• /
• pp.241-271
• /
• 2012

The objectives of this study were to explore the duties and tasks of educational program operation, to develop the performance model including the duties and tasks, and to construct the action manual of the tasks and duties in related with implementing effectively the educational program. The findings of this study were as follows. First, The identifying duties and tasks was 1,942 related with implementing educational program operation based on theoretical job model through activity analysis and experience sampling techniques. Second, the finding duties and tasks was reconstructed through classifying with 9 duties and 88 tasks, and then it was developed as educational program operation model of Korean Rural HRD Center. Finally Third, the implementing manual was constructed including the contents and task-elements.

• Korean Journal of Human Ecology
• /
• v.21 no.3
• /
• pp.407-421
• /
• 2012

The purpose of this study is to plan out a university students' self-development program and to verify the effect of the students in adapting themselves to college life and coping with stress from it. The program was developed as the liberal arts course for a semester and comprised 12 sessions. Each secession of a 150 minutes workshop program. The pre-test, post test regarding students adaptation to college and stress coping methods conducts upon each experimental group and each control group. Each group consisted of 50 subjects. As a result of this research, this study could come to the following conclusions. Firstly, it was found that the university students' self-development program has effect on improving students adaptation to college. Secondly, it was found that the university students' self-development program has effect on improving stress coping methods.