• Journal of information and communication convergence engineering
• /
• v.8 no.5
• /
• pp.591-594
• /
• 2010

Control devices perform various works for us in many areas. The device is being utilized for precision movement of certain object. In as much as control devices are activated by means of motors, motor control is important.[1][2] Generally, servo motors capable of precision control are more frequently used than DC motors. Use of 3 motors allows 3- way movement. Medical controllers for surgical operation require high precision. [3][4][5][6] AX-12, a servo motor can realize various types of movement. AX-12 can be easily manufactured in the form of a robotic arm and has features that MCU and its peripheral circuits are simple. For precision movement, 3 motors can be controlled by use of a single joystick and 2 buttons, with movement angles being adjusted by having preset values in the program changed.[7][8] By virtue of this study, we have realized small precision robotic arm system utilizing single joystick and 2 buttons. This system can control the robotic arm in the direction desired by the user. The system has been designed such that a joystick controls 2 motors with the remaining motor being controlled by a button. Single MCU is tasked with both control and movement.[9] We have shown precision robotic arm system in the Figure contained in the conclusion part and made reference to results of analysis in there. It has also been demonstrated that the system can be utilized in the industry.[8]

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.10 no.4
• /
• pp.147-155
• /
• 2015

Home Shopping companies haven't have any possible means of product quality control process in spite of the fact that they are selling average 16,000 different kinds of product every month. Under this condition, increases of return and product liability can have a strong negative influence on customers' trust in a home shopping brand and intentional repurchase through the same home shopping channel. To solve the problems, we applied adjusted selection and assessment system of manufacturers in home shopping industry, and the consequence of system effect was verified that there is a decrease of 10.3% in the number of returns and a decrease of 11.7% in the number of product liability.

• Geomechanics and Engineering
• /
• v.14 no.1
• /
• pp.91-98
• /
• 2018

Length of a vehicle is an important variation to generate different variants of an automotive platform. This parameter is usually adjusted by embedding dimensional flexibility into different components of the Body in White (BIW) including the floor pan. Due to future uncertainties, it is not necessarily possible to define certain values of wheelbase for the future products of a platform. This work is performed to add flexibility into the design process of a length-variable floor pan. By means of this analysis, the cost and time consuming process of optimization is not necessary to be performed for designing the different variants of a product family. Stiffness and mass of the floor pan are two important functional requirements of this component which directly affect the occupant comfort, dynamic characteristics, fuel economy and environmental protection of the vehicle. A combination of Genetic algorithm, GMDH-type of artificial neural networks and TOPSIS methods is used to optimally design the floor pan associated with arbitrary length of the variant in the defined system range. The correlation between the optimal results shows that for a constant mass of the floor pan, the first natural frequency decreases by increasing the length of this component.

• Journal of Labour Economics
• /
• v.31 no.3
• /
• pp.75-105
• /
• 2008

This paper examines the changes over lime in union relative wage effects during the period of 1988 and 2007. The union wage premium was 3.4 percent in average during the last 20 years. It has fallen in the boom years up to the mid-1990s, but has rapidly risen since the Asian financial crisis of 1997. Time series evidence suggests that the union wage premium is counter-cyclical, which means that it responds to economic conditions with a reverse direction. There has been also a fast increase in the unadjusted wage gap relative to regression-adjusted wage gap during the last 10 years in particular, implying favorable changes in the selection of workers into unionized companies.

• Journal of Nutrition and Health
• /
• v.32 no.4
• /
• pp.437-447
• /
• 1999

The intake of fatty acids, and the effects of fatty acid intake patterns on serum lipid concentrations was investigated in 112 postmenopausal women. Dietary intakes of fatty acids were assessed by means of a semi-quantitative food questionnaire with food models and other measuring tools. The intakes of saturated fatty acid(SFA), monounsaturated fatty acid(MFA) and polyunsaturated fatty acid(PUFA) were 10.85g, 11.89g and 12.09g, respectively. The ratios of P/M/S and $\omega$6/$\omega$3 fatty acid were 1.19 : 1.10 : 1 and 6.65 ; 1, respectively. Serum lipid concentrations were adjusted for age, menopausal period, BMI, stress scores, exercise habit and energy intake and the relationship between fatty acid intake and serum lipids was measured using Pearson's correlation coefficient. Serum cholesterol concentration was positively correlated with dietary intake of SFA (p<0.10), MUFA(p<0.05), palmitic acid(p<0.10), stearic acid(p<0.05), oleic aicd(p<0.05), and arachidonic acid(p<0.10). Serumk LDL-cholesterol concentration was positively correlated with MUFA(p<0.10), oleic acid(p<0.10), oleic acid(p<0.10), and arachidonic acid (p<0.10). Serum triglyceride concentration was positively correlated with arachidonic acid(p<0.10). However, serum HDL-cholesterol concentration was not found to be significantly correlated with any fatty acids.

• Journal of Korea Multimedia Society
• /
• v.23 no.2
• /
• pp.155-165
• /
• 2020

In this paper, we propose a smart thermostat temperature set-point control method based on machine learning and rule engine, which controls thermostat's temperature set-point so that it can achieve energy savings as much as possible without sacrifice of occupants' comfort while users' preference usage pattern is respected. First, the proposed method periodically mines data about how user likes for heating (winter)/cooling (summer) his or her home by learning his or her usage pattern of setting temperature set-point of the thermostat during the past several weeks. Then, from this learning, the proposed method establishes a weekly schedule about temperature setting. Next, by referring to thermal comfort chart by ASHRAE, it makes rules about how to adjust temperature set-points as much as low (winter) or high (summer) while the newly adjusted temperature set-point satisfies thermal comfort zone for predicted humidity. In order to make rules work on time or events, we adopt rule engine so that it can achieve energy savings properly without sacrifice of occupants' comfort. Through experiments, it is shown that the proposed smart thermostat temperature set-point control method can achieve better energy savings while keeping human comfort compared to other conventional thermostat.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.7 no.3 s.18
• /
• pp.122-128
• /
• 2004

Internal blast performance test on developed explosives was carried out. Internal blast means a blast wave in closed chambers like tunnels, bunkers, operation center and chamber of ships. We used Anpa tunnel for our test facility. We performed two series of tests to measure internal blast of developed explosives. Three different kinds of cast PBXs, DXD-09, DXD-10, DXD-18, and conventional explosive, Tritonal, were used in our test. The explosives were cast as a charge of 108mm diameter in a plastic tube of a 3mm thickness. The length of charges 4ere adjusted as a weight 3kg. A melt-cast explosive, tritonal, was used as a reference. Pentolite booster was used. The cylindrical boosters have a 95mm diameter and 47.5mm height. The results showed that there may be some differences between the performances in the air blast tests and those in the internal blast tests. The results showed that DXD-10, the best performance in air blast tests, showed the poorest performance in internal blast among the explosives tested. On the other hand, DXD-18 showed exactly the opposite trend. This is probably due to the highest contents of aluminum and inert binder in DXD-18. DXD-18 has $38\;wt\;\%$ of aluminum and $17\;wt\;\%$ of inert binders.

• Journal of Information Processing Systems
• /
• v.16 no.2
• /
• pp.277-300
• /
• 2020

This paper presents a method for clustering short text documents, such as news headlines, social media statuses, or instant messages. Due to the characteristics of these documents, which are usually short and sparse, an appropriate technique is required to discover hidden knowledge. The objective of this paper is to identify the combination of document representation, document distance, and document clustering that yields the best clustering quality. Document representations are expanded by external knowledge sources represented by a Distributed Representation. To cluster documents, a K-means partitioning-based clustering technique is applied, where the similarities of documents are measured by word mover's distance. To validate the effectiveness of the proposed method, experiments were conducted to compare the clustering quality against several leading methods. The proposed method produced clusters of documents that resulted in higher precision, recall, F1-score, and adjusted Rand index for both real-world and standard data sets. Furthermore, manual inspection of the clustering results was conducted to observe the efficacy of the proposed method. The topics of each document cluster are undoubtedly reflected by members in the cluster.

• 한국해양학회지
• /
• v.4 no.1
• /
• pp.17-35
• /
• 1969

This work concerns morphological studies of the Japaness jack mackerel, Trachurus japonicus(Temminck & Schlegel). A total of 48 random samples consisting of 2669 fish is examined, representing three geographic regions, namely, Kamakura, Nagasaki, and Tottori. Preservation affects length and weight of fish considerably, but the variability after 10 days is shown to be negligible. The variability in measuring the morphometric characters due to different measures and orders is found to be significant. They are relatively small, however, compared to the variability in mean length to be expected in samples drawn from the population. Two meristic characters, namely, anal and second dorsal fin rays and three morphometric characters, namely, head length, first and second dorsal insertion distances are chosen for the study. Results of the statistical analysis reveal that differences in the selected meristic characters among samples within and between regions are found to be significant. In general, it is reasonable to state that the jack mackerel collected in Nagasaki region, on the average, have greatest number of anal fin ray and second dorsal fin ray followed by Kamakura, and Tottori regions in that order. It is found that although no significant differences in the slope of regression line are noticed, the mean differences of the selected morphometric measurements in relation to fish length are found to be significant among samples within each region. Differences in the regression coefficients as well as the adjusted sample means are found to be significant between regions. The analysis suggests that samples from Nagasaki region, on the average, have longest head length and greatest distances from snout to the insertion of first dorsal and second dorsal fins followed by Kamakura, and Tottori regions in that order.

• Proceedings of the KWS Conference
• /
• 2009.11a
• /
• pp.87-91
• /
• 2009

Welding is one of the most important joining processes and the effect of welding residual stresses in the structure has a great deal of influence on its quality. In this paper, recent development in computational welding mechanics, particularly calculation of welding residual stresses, is introduced. The hypoelastic formulation of finite element analysis for thermoelastic-plastic deformation is applied to welding processes to find residual deformations and stresses. Leblond's phase evolution equation coupled with the energy equation is employed to calculate the phase volume fraction; this plays an important role as a kinetics parameter affecting phase fraction effects in the mechanical constitutive equation of welded materials. Furthermore, transformation plasticity is taken into account for an accurate evaluation of stress. The influence of the phase transformation and the transformation plasticity on residual stress is investigated by means of numerical analyses using metallurgical parameters in Leblond's phase evolution equation that are adjusted with respect to various cooling rates in a CCT-diagram. Coding implementation is conducted by way of the ABAQUS user subroutines, UMAT.