• Design & Manufacturing
• /
• v.14 no.3
• /
• pp.17-22
• /
• 2020

As devices such as smartphones, tablet PC, and wearable devices have been miniaturized, the connectors that go into the devices are also designed to be very small. The connector combines the plug and the receptacle to transfer electricity. As devices are miniaturized, the contact shape is formed by partially thinning the thickness of the raw material of the terminal in order to lower the coupling height of the plug and receptacle. The product used in this study is a receptacle terminal used for 0.4mm pitch board to board connector among fine pitch connectors. When the material thickness is reduced by forging the receptacle terminal, the width change of the pin is checked. To reduce the thickness of the material by forging, pre-notching is applied in the first step, forging in the second step, and notching in the third step. After forming the width dimension of the pin to 0.28 mm in the pre-notching process, in the forging process, the material thickness 0.08 mm and 0.02 mm (25%) were forged and the thickness was changed to 0.06 mm and the width change amount of the pin was measured. The facility produced 10,000 pieces at 400 SPM using a Yamada Dobby (MXM-40L) press, and thirty pins were measured and the average value was shown. After forging by using C5210-H (HP) and NKT322-EH, which are frequently used in connectors, analyze the amount of change in each material. The effect of punching oil on forging is investigated by appling FM-200M, which is highly viscous, and FL-212, fast drying oil. This study aims to minimize mold modification by predicting the amount of material change after forging.

• Journal of Biomedical Engineering Research
• /
• v.18 no.4
• /
• pp.491-498
• /
• 1997

This paper describes the arousal measurement and control system using fuzzy logic to prevent drowsy driving. Sugeno's method was used for fuzzy inference in this study. Arousal evaluation and control criteria were modified from result of Nz-IRI analysis depending on arousal sate. Membership function and rule base of fuzzy inference were determined from the modified arousal level criteria When lRl (Inter-SIR Interval) was shorter than 60sec, outputs of both methods were changed from small to big, but output of three step warning method was same level until the next warning range. Since output of fuzzy inference tracked well the change of subject's arousal level, problems of three step warning method could be overcome by fuzzy inference method Furthermore, the output of the fuzzy inference was highly correlated with Nz(r = 0.99). Therefore, the fuzzy inference method for evaluation and the control of arousal will be more effective at real driving situation than three step warning method.

• Journal of Navigation and Port Research
• /
• v.33 no.7
• /
• pp.491-500
• /
• 2009

In order to attract more transshipment cargoes, Busan Port Authority (BPA) has, since 2003, adopted the volume incentive policy by which more than US$ 10 million annually have been paid back to shipping lines that were called at the port. However, having been a transshipment port for the Northeast region of China, the port of Busan has come under threat from bold Chinese port development projects, notably Shanghai, as northern Chinese regionnl ports place more emphasis on building facilities capable of handling growing trade volumes. Undoubtedly this would lead to a decline in transshipment container traffic moved via Busan. The purpose of this paper is to identify some core factors that have been affecting the increase of transshipment cargoes of Busan and further to recommend BPA an improved incentive scheme with which more T/S cargoes can be attracted into the port of Busan To clarity the reason why T/S cargoes have increased in the port of Busan, several steps are made as follows: The first step is to make a quantitative model for explaining the development of T/S cargoes during the last decade. The second step is to define the dependent and the independent variables for multiple regressions after testing variable significance. For this, data collection and the accuracy of validation have been done by the direct interview with the experienced staffs in shipping companies of both domestic and foreign country. After validating the model with collected data, the final step is to find variables which are explaining the model mostly. In conclusion, 2 variables were clearly identified as core factors that explain well the development of T/S cargoes in the port of Busan: 'Mohring effect' and total cost. It is strongly recommended, by an empirical study, that an incentive scheme be changed to a way which more feeder vessels rather than mother vessels can reduce their direct costs to call in the port of Busan.

• Journal of Korea Society of Industrial Information Systems
• /
• v.6 no.2
• /
• pp.23-30
• /
• 2001

The advent of the Internet and development of information technologies have changed the environment of doing business. Accordingly, they expect that the relative importance of electronic commerce in the business becomes growing more and more. Among the areas of electronic commerce, B2B marketplaces that play the roles of linking buyers and suppliers take the important place. This study examines requirements for activating domestic B2B marketplaces by analyzing the literature and the status of the marketplaces. For the analysis, evaluation factors that belong to one of the four categories (i.e., Information step, Agreement step, Settlement step, and the rest) are selected. Results of the study suggest the following activation requirements for domestic B2B marketplaces : 1. Enforcement of services for the Agreement and Settlement steps. 2. Supporting multinational languages. 3. Diversification of income sources. 4. Standardization. 5. Integrating main systems. 6. Satisfying the necessities of buyers and suppliers.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.51 no.1
• /
• pp.89-94
• /
• 2006

Traditionally fatty acid composition used to be analysed by a GC and the sample preparation process includes lipid extraction from sample and subsequent methyl esters preparation, which are time-consuming and cumbersome. As an alternative, simultaneous extraction/methylation methods are being developed for rapid and simplified sample preparation. To optimize one-step extraction/methylation method for analysis of fatty acid composition in brown rice, various reaction factors such as sample to reaction solution ratio, reaction time and temperature, shaking intensity were changed and resultant fatty acid composition data were evaluated in comparison with previous reports. The ratio of sample weight to reaction solution volume was the most critical factor in that higher sample to reaction solution ratio caused overestimation of palmitic acid and linoleic acid composition, resulting in underestimation of oleic acid. Lower reaction temperature also induced overestimation of linoleic acid and underestimation of oleic acid. Reaction duration and the intensity of shaking prior to and during the reaction, however, caused no significant changes in analysis results. In conclusion, the optimum condition was mixing 5 grains (about 0.2 g) of brown rice with $680{\mu}L$ of extraction/methylation mixture and $400{\mu}L$ of heptane, followed by reaction at $80^{\circ}C$ for 2 hours.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.7
• /
• pp.1536-1541
• /
• 2009

In this paper, we present a novel pulse train identification method for two step stagger pulse train. Generally radar uses a fixed pulse train, and it is easy for electronic warfare system to measure the pulse repeat interval(PRI) and identify the radar. But it is very difficult to measure the PRI of stagger pulse radar because the pulse interval is periodically changed. We suggest a novel method to measure the PRI and identify the radars using the second deviation of pulse train. This method is faster comparing with Histogram method. We have a good PRI measurement results for 2 step stagger signals.

• The KIPS Transactions:PartB
• /
• v.9B no.5
• /
• pp.673-680
• /
• 2002

This paper proposes a method for detecting edge using an evolutionary programming and a momentum back-propagation algorithm. The evolutionary programming does not perform crossover operation as to consider reduction of capability of algorithm and calculation cost, but uses selection operator and mutation operator. The momentum back-propagation algorithm uses assistant to weight of learning step when weight is changed at learning step. Because learning rate o is settled as less in last back-propagation algorithm the momentum back-propagation algorithm discard the problem that learning is slow as relative reduction because change rate of weight at each learning step. The method using EP-MBP is batter than GA-BP method in both learning time and detection rate and showed the decreasing learning time and effective edge detection, in consequence.

• Ceramist
• /
• v.21 no.4
• /
• pp.427-432
• /
• 2018

In this study, the aspherical lens for optical communications produced not with an one-step pneumatic type of external pressurization system (existed GMP process) but a constant weight of self-loaded mold put up to upper core. So the lens is molding with self-loaded weight molding and it calls Weight Molding process. In self-loaded molding process, we measured changes of center thickness molding lenses with each variable molding temperatures and time to find the effect of center of lens thickness to search key factors. As experimental results, the center thickness reach to targeted lenses step time value was changed drastically and it depends by molding temperature. If the molding temperature gets higher, the targeted lens that is reaching to the center thickness step time value was decreased. To find the effect of life improvement on mold core by imposing the self-loaded molding process we molded with GMP(Glass molding press) method and self-loaded molding method for 9,000 times and measured the lenses shape accuracy and surface roughness to evaluate the core life. As a result the self-loaded molding method core has 2,000 times longer that GMP (Glass molding press) method. If we adopt self-loaded molding method of the optical aspherical lens molding in the future, we expect that it would reduce the expense of changing the molds by molding core life improvements.

• Journal of the Korea Convergence Society
• /
• v.12 no.10
• /
• pp.1-8
• /
• 2021

In online meetings and classes using webcams, the chromakey technique is a very necessary part to produce content. We proposed a technology that enables background synthesis without using a cloth for chromakey. The proposed method consists of three steps: an HSI image conversion step, a step of detecting a region changed from a background, and a step of replacing the background region with a chromakey and applying it. In the input video, the block average image of each frame is calculated, and the difference between the block average image of the background image and the block average image of the input image is used to detect the change area. The developed chromakey effect technology uses a technique of acquiring a background image without an object from a single camera and extracting only an object by distinguishing the moving object and the background. The proposed method is not only capable of processing even if the background has a variety of colors, but also has the seamless processing of the boundary lines of objects.

• Journal of the Korean Geosynthetics Society
• /
• v.18 no.3
• /
• pp.79-88
• /
• 2019

This study described a results of groundwater injection test in cavity, in order to evaluate characteristics of cavity expansion under pavement. That is, groundwater amount proportional to the cavity volume was injected into the generated cavity step by step, and then the cavity with the changed size was monitored as the injected groundwater was drained. The test result showed that the cavity volume by groundwater injection increased, and then it converged or decreased. This means that some of the relaxation soil around the cavity collapsed, and the fine-grained soils in some soils filled the void in the surrounding soils when the cavity is expanded by groundwater injection. The volume change and expansion characteristics of the cavity according to the groundwater injection step were analyzed. The result showed that the cavity extended laterally. Therefore, it was found that the cavity expansion is caused by the repetition of the relaxation soil collapse due to the groundwater flow and the loss of the collapsed soil below the cavity.