• Journal of Korean Society for Quality Management
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• v.45 no.2
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• pp.191-207
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• 2017

Purpose: To develop an interactive version of the conventional process capability-based approach, called 'Interactive Process Capability-Based Approach (IPCA)' in multi-response surface optimization to obtain a satisfactory compromise which incorporates a decision maker(DM)'s preference information precisely. Methods: The proposed IPCA consists of 4 steps. Step 1 is to obtain the estimated process capability indices and initialize the parameters. Step 2 is to maximize the overall process capability index. Step 3 is to evaluate the optimization results. If all the responses are satisfactory, the procedure stops with the most preferred compromise solution. Otherwise, it moves to Step 4. Step 4 is to adjust the preference parameters. The adjustment can be made in two modes: relaxation and tightening. The relaxation is to make the importance of one of the satisfactory responses lower, which is implemented by decreasing its weight. The tightening is to make the importance of one of the unsatisfactory responses higher, which is implemented by increasing its weight. Then, the procedure goes back to Step 2. If there is no response to be adjusted, it stops with the unsatisfactory compromise solution. Results: The proposed IPCA was illustrated through a multi-response surface problem, colloidal gas aphrons problem. The illustration shows that it can generate a satisfactory compromise through an interactive procedure which enables the DM to provide his or her preference information conveniently. Conclusion: The proposed IPCA has two major advantages. One is to obtain a satisfactory compromise which is faithful to the DM preference structure. The other is to make the DM's participation in the interactive procedure easier by using the process capability index in judging satisfaction/unsatisfaction. The process capability index is very familiar with quality practitioners as well as indicates the process performance levels numerically.

• Journal of KIISE:Information Networking
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• v.35 no.6
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• pp.529-537
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• 2008

AODV routing protocol is intended for use by mobile' nodes in an ad-hoc network. In AODV nodes create routes on an on-demand basis. As the degree of node mobility becomes high, however, the number of the control packets, RREQ and RREP messages, have increased so rapidly. The unexpected increases in the number of the control packets cause the destination node to decrease the packet receiving rate and also to increase the overall energy consumption of such a network. In this paper, we propose a novel method of adaptively controlling the occurrences of such RREQ messages based on AIAD (additive increase additive decrease) under a consideration of the current network status. We have tested our proposed method with the conventional AODV and the method using timestamp based on the three performance metrics, i.e.. how long does node moves, node velocity, and node density, to compare their performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3C
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• pp.92-101
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• 2005

It is difficult to detect the accurate detection which leads the camera it moves follows in change of the noise or illumination and Also, it could be recognized with backgound if the object doesn't move during hours. In this paper, the proposed method is updating changed background image as much as N＊M pixel mask as time goes on after get a difference between imput image and first background image. And checking image pixel can efficiently detect moving by computing fixed distance pixel instead of operate all pixel. Also, set up minimum area of object to use boundary point of object abstracted through checking image pixel and motion detect of object. Therefore motion detection is available as is fast and correct without doing checking image pixel every Dame. From experiment, the designed and implemented system showed high precision ratio in performance assessment more than 90 percents.

• Journal of KIISE:Information Networking
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• v.34 no.1
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• pp.48-61
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• 2007

WiBro (Wireless Broadband) service, developed in Korea, can provide the host mobility while its users hang around within the subnet. Next-generation Internet protocols, IPv6 and Mobile IPv6 (MIPv6), provide a plenty of addresses to the nodes and enable the handover between different subnets. However, MIPv6 is not enough to support a real time service such as VoIP (Voice over IP) due to the long latency, and it is necessary to develop an enhanced handover mechanism which is optimized to the WiBro networks. In this paper, we suggest an improved fast handover mechanism while the mobile node moves around WiBro networks. The proposal is based on Fast Mobile IPv6 (FMIPv6) which is the representative protocol for fast handover, and reduces the handover latency by the close interaction between the link layer (WiBro MAC) and IP layer (FMIPv6). Finally, we analyze the performance of proposed mechanism through the mathematical analysis.

• Journal of Soil and Groundwater Environment
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• v.20 no.5
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• pp.34-40
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• 2015

It is reported that the intensity of rainfall will likely increase, on average, over the world on 2000. For water resources security, many studies for flow paths from rainfall or snowmelt to subsurface have been conducted. In Korea, few isotopic studies for characterizations of flow path have been undertaken. For a better understanding of how water derived from atmosphere moves to subsurface and from subsurface to stream, an analysis of precipitation and stream water using oxygen-18 and deuterium isotopes in a small watershed, Dorim-cheon, Seoul, was conducted with high resolution data. Variations of oxygen-18 in precipitation greater than 10‰ (δ¹⁸O_max = −1.21‰, δ¹⁸O_min = −11.23) were observed. Isotopic compositions of old water (groundwater) assumed as the stream water collected in advance were −8.98‰ and −61.85‰ for oxygen and hydrogen, respectively. Using a two-component mixing model, hydrograph separation of the stream water in Dorim-cheon was conducted based on weighted mean value of δ¹⁸O. As a result, except of instant dominance of rainfall, contribution of old water was dominant during the study period. On average, 71.3% of the old water and 28.7% of rainfall contributed to the stream water. The results show that even in the small watershed, which is covered with thin soil layer in granite mountain region, the stream water is considerably influenced by old water inflow rather than rainfall.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.1069-1078
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• 2013

The paper is about teaching culture in a language learning. There are many teachers who are afraid of teaching foreign language with culture. They are delighted to teach politics, economics, history, art and literature as objective culture. But they are hesitant to teach subjective culture which is connected with a communication competency. The paper suggests three stages to instruct culture in a schoolroom. The first stage, it is growing out of the self-centered view. The second step, be developing self-consciousness through comparing mother culture with target culture. The last stage, it has to response to appropriately target culture. The teaching materials for the model suggested are two movies. Because the cultural aspects in the moves are subjective culture, so it has something in common with target cultural situations in a language learning. This method which is teaching culture in a the language learning has the advantage of being easy to teachers and learners. Most students like to watch a movie. The teaching material is The Chronicles of Narnia : The Lion, the Witch and The Wardrobe와 Guess Who?. I hope that this suggestion for cultural teaching is helpful for understanding each other.

• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.410-416
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• 2007

This paper presents quantitative analysis of a training system based on an unstable platform and a visual interactive system for improving sense of equilibrium. The training system consists of an unstable platform, a force plate, a safety harness, a monitoring device, and a personal-computer. To confirm the effects of the training system, fifteen young volunteers and five elderly volunteers went through a series of balance training using the system. During the training, we measured relevant parameters such as the time a subject maintain his or her center of pressure on a target, the time a subject moves his or her center of pressure to the target, and the mean absolute deviation of the trace before and after training with this system and training programs to evaluate the effects of the training. The results showed that the training system can successfully assess the gradual improvement of the postural control capability of the subject in the system and showed a possibility of improving balance of the subject. Moreover, the significant improvement in the postural capability of the elderly subject suggests that elderly subjects can benefit more from the training using the system for the improvement of sense of equilibrium.

• Journal of Educational Research in Mathematics
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• v.9 no.2
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• pp.383-404
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• 1999

This study began with an epistemological question about the nature of mathematical cognition in relation to the learner's activity. Therefore, by examining Piaget's 'reflective abstraction' theory which can be an answer to the question, we tried to get suggestions which can be given to the mathematical education in practice. 'Reflective abstraction' is formed through the coordination of the epistmmic subject's action while 'empirical abstraction' is formed by the characters of observable concrete object. The reason Piaget distinguished these two kinds of abstraction is that the foundation for the peculiar objectivity and inevitability can be taken from the coordination of the action which is shared by all the epistemic subjects. Moreover, because the mechanism of reflective abstraction, unlike empirical abstraction, does not construct a new operation by simply changing the result of the previous construction, but is forming re-construction which includes the structure previously constructed as a special case, the system which is developed by this mechanism is able to have reasonability constantly. The mechanism of the re-construction of the intellectual system through the reflective abstraction can be explained as continuous spiral alternance between the two complementary processes, 'reflechissement' and 'reflexion'; reflechissement is that the action moves to the higher level through the process of 'int riorisation' and 'thematisation'; reflexion is a process of 'equilibration'between the assimilation and the accomodation of the unbalance caused by the movement of the level. The operational learning principle of the theorists like Aebli who intended to embody Piaget's operational constructivism, attempts to explain the construction of the operation through 'internalization' of the action, but does not sufficiently emphasize the integration of the structure through the 'coordination' of the action and the ensuing discontinuous evolvement of learning level. Thus, based on the examination on the essential characteristic of the reflective abstraction and the mechanism, this study presents the principles of teaching and learning as following; $\circled1$ the principle of the operational interpretation of knowledge, $\circled2$ the principle of the structural interpretation of the operation, $\circled3$ the principle of int riorisation, $\circled4$ the principle of th matisation, $\circled5$ the principle of coordination, reflexion, and integration, $\circled6$ the principle of the discontinuous evolvement of learning level.

• Ocean and Polar Research
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• v.35 no.1
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• pp.27-37
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• 2013

The western coast of Anmyeondo is open toward the Yellow sea and the northern and southern coasts are sandy and have simple coastlines. In this study, we investigated the spatial distribution and community structure of the macrobenthos that inhabit the sandy shore of Anmyeondo. For the study, we chose 8 sites encompassing 44 stations. In total, we have recorded 62 species, and collected 747 inds./$m^2$ on average. Zonation pattern did not appear because the mean grain size and organic contents of the study sites were similar among the macrobenthos. Polychaetes were most frequently recorded, but amphipods appeared in higher mean density. Macrobenthic community is classified into 3 groups largely based on the density difference among the dominant species and the groups were not influenced by environmental factors. The aggregated distribution of macrobenthos did not show a clear regional spatial difference but exhibited classification pattern emphasizing the density difference of the dominant species. The sandy shores of Anmyeondo are relatively more influenced by waves compared to other regions and the sediment moves more due to strong winds, etc. at low tide. We presume that the movement of sediment resulted in a relatively even sedimentary environment and consequently weakened environmental variables that change with the tide level. We concluded that the macrobenthic community does not show the zonation pattern in the sandy shores of Anmyeondo due to such influences.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.672-680
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• 2017

A solar photovoltaic system is composed of a module mounting structure, supporting trunk, and a control unit that supplies generated electrical power to an external power grid or a load. The efficiency of the system depends on the incident solar light, so the mounting structure is installed to face the sun. However, because the sun always moves, systems that track the sun have better efficiency than fixed systems. The structure experiences wind pressure, snow load, seismic load, and structure weight. The wind pressure has the most serious effect on the structure. The pressure was obtained using finite element method for various gaps between modules and angles between the panel and the ground. The wind pressure is lowest when the gap is zero, and it increases with the inclination angle. Based on the results, a mounting structure module was designed.