• Transactions of the Korean Society of Automotive Engineers
• /
• v.5 no.2
• /
• pp.1-12
• /
• 1997

A computer program was developed to simulate effect of the initial track tension on the tractive performance of tracked vehicles. The performance was evaluated in terms of drawbar pull, motion resistance, tractive coefficient and tractive efficiency. Results of the simulation showed that increase in track tension decreases the sinkage and mean maximum pressure in clay, making the ground pressure distribution more uniform. This tendency became more evident when the number of roadwheels increased. However, such change in MMPs was negligible in firm soils. Motion resistance was also decreased with increase in track tension and the number of roadwheels. Under weak soil conditions, tractive coefficient and efficiency increased generally as the track tension increased for a slip range of 10∼30%. For slippage less than 3∼4%, however, the tractive coefficient decreased with increase in track tension. In general, it was known that increasing track tension improves tractive performance in weak soil conditions. However, high track tension can reduce efficiency due to the increment of internal motion resistance caused by increased track tension.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.5
• /
• pp.335-343
• /
• 2021

Profit generation is one of the main goals of small- and medium-sized enterprises (SMEs). SMEs have deployed a number of solutions to increase profits, including solutions to improve their financial advantage. The question is how to help SMEs make better and more effective decisions to improve their competitive advantage in order to improve their financial performance. The aim of this research is to examine the impact of competitive advantage on financial performance in small- and medium-sized enterprises (SMEs) in Hanoi. A survey of 120 accountants, sales staff and boards of directors of SMEs was conducted to collect data. Through quantity methodology, we used Cronbach's Alpha, EFA and correlation analysis to determine the relationship between competitive advantage and dependent variable - financial performance. The results showed that the competitive advantage had a positive relationship with financial performance. There is not, statistically, significant difference in the level of financial performance in SMEs in Hanoi in terms of genders and between the mentioned three groups of job descriptions. From the findings, this study suggests several recommendations to improve financial performance such as increase sales and increase profits. The results are considered as a useful reference for establishing policies to attract customers toward sustainable development of firms.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.26 no.3
• /
• pp.234-245
• /
• 2023

The Arena Fragmentation Test(AFT) is designed to analyze warhead performance by measuring fragmentation data. In order to evaluate the results of the AFT, a set of AFT images are captured by high-speed cameras. To detect objects in the AFT image set, ResNet-50 based Faster R-CNN is used as a detection model. However, because of the low resolution of the AFT image set, a detection model has shown low performance. To enhance the performance of the detection model, Super-resolution(SR) methods are used to increase the AFT image set resolution. To this end, The Bicubic method and three SR models: ZSSR, EDSR, and SwinIR are used. The use of SR images results in an increase in the performance of the detection model. While the increase in the number of pixels representing a fragment flame in the AFT images improves the Recall performance of the detection model, the number of pixels representing noise also increases, leading to a slight decreases in Precision performance. Consequently, the F1 score is increased by up to 9 %, demonstrating the effectiveness of SR in enhancing the performance of the detection model.

• Journal of Advanced Marine Engineering and Technology
• /
• v.22 no.6
• /
• pp.871-879
• /
• 1998

The refrigerator consists of many components such as compressor condenser expansion valve evaporator and the cabinet which filled by urethane foam. In this paper the heat leakage of refriger-ator is measured by the new experiment method which is different from a present method, The devi-ation of the UA(overall heat transfer coefficient times area) between the simulation and experiments is about 7-8%. Using the modeling of various components of refrigeration system a performance analysos of CFC 12 and HFC 134a is performed numerically on the UA. As the results of this study according to increase the heat leakage the refrigeration load and mass flow rate of refrigerant are increased. And the increase of the mass flow rate results in the increase of the condensing and evapo-rating temperature. Therefore according to increase of the heat leakage the COP leads to increase because the increase of refrigeration capacity is larger than the increase if compressor power.

• Steel and Composite Structures
• /
• v.48 no.1
• /
• pp.89-102
• /
• 2023

This study investigates the eccentric performance of concrete-filled steel tubular (CFST) stub columns strengthened with steel tube and sandwiched concrete (STSC) jackets. It was revealed that the STSC jacketing method effectively weakened the cracking of concrete in CFST columns on the convex side and the crash on the concave side. Substantial increases in the eccentric bearing capacities were demonstrated after strengthening. A numerical study was further conducted. The decrease in diameter-to-thickness ratio and increase in strength of outer tube contributed to increase in peak load of all components, whereas the increase in sandwiched concrete strength resulted in load increase on itself and had negligible effects on other components. The parametric study showed the effect of inner concrete strength on columns' bearing capacity was magnified after strengthening, whereas that of inner tube thickness was reduced. Within the parameters investigated, high-strength concrete and high-strength steel can be applied without the concern of early abrupt failure of inner low-strength concrete or steel tube.

• Magazine of the Korea Concrete Institute
• /
• v.8 no.5
• /
• pp.163-170
• /
• 1996

Cellulose fibers, being fairly strong and stiff as well as cheap and plentiful with low energy demand during manufacture, are strong contenders for the reinforcement of cement-based materials. Cellulose fiber-cement composites, generally manufactured by slurry-dewatering procedure, can find applications in the production of flat and corrugated cement sheets and many other thin-sheet cement products. This paper presents the results of an experimental study concerned with the effects of fiber content and moisture conditions on the flexural performance of these composites. An effort was also made to study the effect of pozzolanic admixtures on the flexural performance in different moisture conditions. The test results obtained were analyzed statistically using the analysis of variance in order to derive reliable conclusions. The results generated in this study were indicative of significant effects of fiber content and moisture condition of flexural performance. There is a tendency in flexural strength to increase in increase in fiber content up to 8%: flexural toughness values continue to increase even at higher fiber contents. Moisture content has a significant effect on the flexural performance. There is a tendency in flexural strength to decrease and flexural toughness to increase with increasing moisture content Composites incorporating pozzolans showed an increase in the flexural strength while slightly reducing the flexural toughness and were sensitive to variations in moisture content.

• Journal of Labour Economics
• /
• v.32 no.2
• /
• pp.27-60
• /
• 2009

Some fact-findings which were gained as results of regression analysis with Workplace Panel Survey data about whether Employee Participatory High Performance Work Practices could help to increase the compensation of workers are as followings. Firstly. though High Performance Work Practices wert generally estimated to have positive effects on management performance of establishments, their positive effects were not so significant except in cases of some practices. Secondly, the wage increase effects of the main High Performance Work Practices were much stronger with statistical significance. Thirdly. in case of unionized establishments. the wage increase effects of the main High Performance Work Practices were estimated to be much stronger than in the Don-unionized.

• Journal of the Korean Wood Science and Technology
• /
• v.33 no.2 s.130
• /
• pp.40-55
• /
• 2005

This study was carried out to discuss the feasibility of wood and plastic wastes as the raw materials for wood particle-plastic composites. For this purpose, composites were manufactured from coarse and fine wood particles and polypropylene fibers by nonwoven web process. And the effect of wood particle size on the performance of the composites were analyzed according to ASTM D 1037-93. In the physical properties of composites, water absorption decreased with the increase of target density and polypropylene fiber content. And the composites with fine wood particles appeared to have slightly lower water absorption than those with coarse wood particles. Thickness swelling did not vary significantly with the increase of target density but increased with the increase of wood particle content. And the composites with fine wood particles were significantly lower in thickness swelling than those with coarse wood particles. In the mechanical properties of composites, dry and wet MOR showed the increasing tendency with the increase of polypropylene fiber content and target density. Dry and wet MOE showed the increasing tendency with the increase of target density but only wet MOE exhibited the increasing tendency with the increase of polypropylene fiber content. Composites with fine wood particles appeared to be generally higher in wet MOR and MOE than those with coarse wood particles. In conclusion, composites with fine wood particles showed generally higher performance than those with coarse ones. Also, composites were significantly superior to control particleboards in the performance, especially in water absorption and thickness swelling.

• Progress in Superconductivity and Cryogenics
• /
• v.4 no.2
• /
• pp.63-67
• /
• 2002

In this study, the performance of the Stirling type orifice Pulse tube refrigerator (OPTR) with a linear compressor was investigated by experiment. The dynamic pressures at three points and a temperature at the cold heat exchanger are measured to explore the dependency of the orifice on the performance of the OPTR. The experimental results show that the opening of the orifice has significant effects on the no load temperature and cool down characteristics. The Pressure amplitude in Pulse tube decrease as the opening of the orifice increase, but the mass flow rate through the orifice and the electric input Power to the compressor increase. The results show that the operating frequency and charging Pressure does not affect on the no load temperature. The pressure amplitude in pulse tube decrease as the operating frequency increase or the charging Pressure decreased.

• Journal of the Korea Safety Management & Science
• /
• v.18 no.3
• /
• pp.117-125
• /
• 2016

The organization which is does sale activity in 21c, face a radical environment changes and high competition. To overcome from these situation, employee who is does sale in field are important to set sustainablity to the organization. A sales person is one of member in organizations, so they have a relation with other employee in process of job. To increase there performance and satisfaction, LMX is focused by many researchers. LMX can increase job satisfaction which can increase job performance thought organizational justice. And career of employee can has moderate effect between LMX and organizational justice. To figure out casual relationship among factors, researcher conduct a empirical analysis use 210 samples from SME saleman. Result of empirical study show us every hypothesis which researcher set up has supported. Based on this result, reseacher provide manageric implications and conclusions.