• Journal for History of Mathematics
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• v.17 no.2
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• pp.97-103
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• 2004

In this paper, we will prove that a free join algebra and a universal derivation module of its subalgebras have a universal derivation module induced by its subalgebras.

• International Commerce and Information Review
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• v.15 no.1
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• pp.309-330
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• 2013

Trans-Pacific Partnership started as a small scale 4 countries regional trade agreement. It became a grand free trade agreement when the United States announced its participation and Japn considers to join. Korea still hasn't decided the stance however, considering the economic and political relationship with the United States and the impact of TPP, it looks like that Korea is going to join TPP. US led the TPP agreement is expected to be made based on the previous FTA agreements of the US. In the promising E-Commerce part, it is likely that the e-commerce leading US would suggest favorable agreement. If Korea joins the TPP, it's necessary to suggest what Korea wants and needs based on the previous KORUS FTA to promote Korean e-commerce for the future.

• Journal of Applied Reliability
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• v.13 no.2
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• pp.109-116
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• 2013

The solder is any of various fusible alloys, usually tin and lead, used to join metallic parts that provide the contact between the chip package and the printed circuit board. Solder plays an important role of electrical signals to communicate between the two components. In this study, two kinds of Ag-free solder as sample is made to conduct the thermal shock test and the high humidity temperature test. Low resistance is measured to estimate crack size of solder, using daisy chain. The low speed shear test is also performed to analyze strength of solder. The appropriate degradation model is estimated using the result data. Depending on the composition of solder, lifetime estimation is conducted by adopted degradation model. The lifetime estimated two kinds of Ag-free solder is compared with expected lifetime of Sn-Ag-Cu solder. The result is that both Ag-free composition are more reliable than Sn-Ag-Cu solder.

• Korean Journal of Applied Biomechanics
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• v.33 no.4
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• pp.128-136
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• 2023

Objective: The aim of this study was to investigate the effect of an 8-week closed kinetic chain typed Reformer and Chair Pilates exercise on static and dynamic lower limb alignment for healthy female adults. Method: Ten healthy young female adults without musculoskeletal injury history in last 6 months (Age: 29.3 ± 3.5 yrs., Height: 165 ± 3.4 cm, Body mass: 58.2 ± 5.4 kg) participated in this study. All participants asked to join the 8-week closed kinetic chain typed Reformer and Chair Pilates exercise, and the program was conducted for 60 minutes twice a week. Participants were asked to be measure a static Q-angle and performed free squat one week before and after the program. A 3-D motion analysis with 8 infrared cameras and 5 channels of EMG was executed in this study. The effectiveness of the training was evaluated by paired t-test, and the significance level was set at .05. Results: A significantly decreased in internal rotation angles was found at hip joint during free squat after the training. Also, significantly decreased in lateral rotation angles were found at knee and ankle joint during free squat after training. Finally, significantly decreased in muscle activations were found at adductor longus and peroneus longus during free squat after training. Conclusion: From results of our study, it is concluded that an 8-week closed kinetic chain typed Pilates exercise positively effect on lower limb alignment during dynamic movement.

• Journal of Welding and Joining
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• v.6 no.3
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• pp.21-26
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• 1988

The behavior of angular distortion in butt joint wleding of thin plate structure is investigated with an experimental model and partially with a computational model. The experimental model studying the effects of specimene size and degree of restraint on the angular distorion offers a good method for analyzing the behavior of the distrotion. In addition, the distrotion during welding was demonstrated by both experimental measurement and numericla prediciton. The facts evealed in this study are as follows : 1) distrotion angles were changed with variations of specimene wldth. 2) With the restraint, angular distrotion was reduced to 20% to that of free joint. 3) After the restraint being removed, the effect of restraint was also remained. 4) Same heat input per unit thickness caused same amount of distortion. 5) The mode of angular distortion was expected to be changed with expected to be changed with time, i.e. convex movement during heating and concave one during cooling.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.2
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• pp.112-122
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• 1995

While many surfaces such as automobile outer panels, ship hulls and airfoils are characterized by their smooth, free-form shapes, a far larger class of functional surfaces are characterized by highly irregular, multi-featured shapes consisting of pockets, channels, ribs, etc. In constaract to the design of aesthetic, free-form surfaces, functional surface design can perhaps best be viewed as a process of assembling a collection of known component surfaces to form a single compound surface. In this paper, we presents a feature-based functional surface modeling method. A single feature involves a secondary surface, which we must join to a primary surface with a smooth transition between two boundary courves. Through recursive blending of a secondary surface with the primary surface, the mullti-featured surface is represented. After constructing a compound surface, we generate the Z-map for NC machining of the surface. Offsetting the Z-map using the inverse offsetting technique, we get CL tool paths with out gouging.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.4
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• pp.65-68
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• 2013

A novel bumping process using solder bump maker (SBM) is developed for fine-pitch flip chip bonding. It features maskless screen printing process. A selective solder bumping mechanism without the mask is based on the material design of SBM. Maskless screen printing process can implement easily a fine-pitch, low-cost, and lead-free solder-on-pad (SoP) technology. Its another advantage is ternary or quaternary lead-free SoP can be formed easily. The process includes two main steps: one is the thermally activated aggregation of solder powder on the metal pads on a substrate and the other is the reflow of the deposited powder on the pads. Only a small quantity of solder powder adjacent to the pads can join the first step, so a quite uniform SoP array on the substrate can be easily obtained regardless of the pad configurations. Through this process, an SoP array on an organic substrate with a pitch of 130 ${\mu}m$ is, successfully, formed.

• East Asian Economic Review
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• v.17 no.4
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• pp.333-359
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• 2013

Two mega-regional negotiations are changing the landscape of Asia Pacific trade policy: an Asian track centered on ASEAN (the Regional Comprehensive Economic Partnership or RCEP), and a Trans-Pacific track centered on the Trans-Pacific Partnership (TPP) among 12 economies, including the United States, which Korea is expected to join. Modeling results suggest that both would generate substantial benefits for Korea and the global economy. From Korea's viewpoint, the agreements would establish new FTAs with China, Japan and smaller economies, improve the utilization of FTAs by permitting the regional cumulation of inputs, and help to upgrade some Korean FTAs to more rigorous standards. By participating in these agreements, Korea could also help to guide them toward inclusive, high-quality regional outcomes. As one of the region's most open and agile economies, Korea has a large stake in regional integration and would be well advised to pursue both tracks.

• Communications of the Korean Mathematical Society
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• v.11 no.2
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• pp.481-493
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• 1996

We consider a retrial queue with two classes of customers where arrivals of class 1(resp. class 2) customers are MMPP and Poisson process, respectively. In the case taht arriving customers are blocked due to the channel being busy, the class 1 customers are queued in priority group and are served as soon as the channel is free, whereas the class 2 customers enter the retrial group in order to try service again after a random amount of time. We consider the following retrial rate control policy, which reduces their retrial rate as more customers join the retrial group; their retrial times are inversely proportional to the number of customers in the retrial group. We find the joint generating function of the numbers of custormers in the two groups by the supplementary variable method.

• Korean Journal of Acupuncture
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• v.20 no.3
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• pp.91-99
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• 2003

Effects of cheungho aqua-acupuncture at gansoo$(BL_{18})$ and illweul$(GB_{14})$ on plasma lipid composition were investigated in rat fed high fat diet. Body weight gain showed a tendency to decrease in aqua-acupuncture groups and in aqua-acupuncture groups, gansoo and illweul join aqua-acupuncture group showed a lower values than other aqua-acupuncture groups. Concentrations of plasma triglyceride, free fatty acids, lipoprotein and glucose showed a tendency to decreasea in the aqua-acupuncture groups. However in aqua-acupuncture groups, these values showed no significantly different. In plasma lipid composition, total cholesterol and LDL- cholesterol showed a tendency to decrease in aqua-acupuncture groups, however the values of LDL-cholesterol showed no significantly different in the aqua-acupuncture groups. HDL-cholesterol concentration showed a tendency to increase in aqua-acupuncture groups and in aqua-acupuncture groups, gansoo aqua-acupuncture group showed a high value.