• School Mathematics
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• v.17 no.3
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• pp.515-530
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• 2015

The concepts of sample and sampling are central to make a statistically correct decision, so we need to be emphasized their importance in the statistics education. Nevertheless, there were not enough studies which discuss how to teach the concepts of sample and sampling. In this study, teaching sample and sampling is addressed by foreign curricula and cases of instruction in order to obtain suggestions for teaching sample and sampling. In particular, the curricular of Australia, New Zealand, England and the United States are analyzed, considering the sample representativeness and the sampling variability; the two elements in the concept of sample. Also foreign textbooks and cases of instruction when it comes to teach sample are analyzed. The results say that with respect to teach sample can be divided into four suggestions: first, sample was taught in the process of statistical inquiry such as data collection, analysis, and results. Second, sample was introduced earlier than Korea curriculum. Third, when it comes to teach sample, sample variability, as well as sample representativeness was considered. Fourth, technological tools were used to enhance understanding sample.

• Earthquakes and Structures
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• v.6 no.6
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• pp.647-664
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• 2014

A reduction of the response of irregular structures subjected to earthquake excitation by control devices equipped by suitable control algorithm is proposed in this paper. The control algorithm, which is used, is the pole placement one. A requirement of successful application of pole placement algorithm is a definition-selection of suitable poles (eigen-values) of controlled irregular structures. Based on these poles, the required action is calculated and applied to the irregular structure by means of control devices. The selection of poles of controlled irregular structure, is a critical issue for the success of the algorithm. The calculation of suitable poles of controlled irregular structure is proposed herein by the following procedure: a fictitious symmetrical structure is considered from the irregular structure, adding vertical elements, such as columns or shear walls, at any location where is necessary. Then, the eigen-values of symmetrical structure are calculated, and are forced to be the poles of irregular controlled structure. Based on these poles and additional damping, the new poles of the controlled irregular structure are calculated. By pole placement algorithm, the feedback matrix is obtained. Using this feedback matrix, control forces are calculated at any time during the earthquake, and are applied to the irregular structure by the control devices. This procedure results in making the controlled irregular structure to behave like a symmetrical one. This control strategy can be applied to one storey or to multi-storey irregular buildings. Furthermore, the numerical results were shown that with small amount of control force, a sufficient reduction of the response of irregular buildings is achieved.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.59-68
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• 2013

iPod Touch provided so various application software beyond the early music playback function, and enhanced its UI to the level of UX. Because of these, it was evaluated as innovative. In addition, even though various images were provided through the Internet, some people still classify MP3P as audio device in its product category. As for how audio device became video or image device and which factor contributed to such happening, there may be various factors, such as social, cultural, and technical change, other than fundamental change of medium itself. This study is regarding medium characteristics of MP3Player. In other words, this study classified genealogical changes, which can be categorized into 4 points. This study also analyzed the property of each point according to this classification. The result of analysis showed that there is a relation with technological as well as social context in such genealogical change in MP3player. Even though there are various elements in the change of a device, it can be suggested that the factors of genealogical change in MP3player are influenced by a totality of social needs and contexts and technical changes.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.5
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• pp.694-702
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• 2014

One of the most important devices in an underwater vessel is a propulsion system. It should be a quiet and efficient system for stealthy operations in the large mission area. Hence lead-acid battery system has been used to supply the energy to electric motor. Recent technological developments and improvements, such as polymer electrolyte membrane(PEM) fuel cell and lithium polymer battery and have created the potential to improve overall power and propulsion performance. An underwater vessel always starts their mission with a limited energy and is not easy to refuel. Therefore design of energy elements, such as fuel cell and battery, and their load distribution are important to increase the maximum operating time of underwater vessel. In this paper, the lead-acid battery/PEM fuel cell and lithium polymer battery/PEM fuel cell were suggested as propulsion system and their performances were analyzed by modeling and simulation using Matlab/Simulink. Each model concentrated on representing the characteristics of energy element depending on demand current. As a result the effect of load distribution between battery and fuel cell was evaluated and the operation time of each propulsion system was able to be estimated exactly.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.326-326
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• 2014

It has been known since the mid 1960s that Ag can be photodissolved in chalcogenide glasses to form materials with interesting technological properties. In the 40 years since, this effect has been used in diverse applications such as the fabrication of relief images in optical elements, micro photolithographic schemes, and for direct imaging by photoinduced Ag surface deposition. ReRAM, also known as conductive bridging RAM (CBRAM), is a resistive switching memory based on non-volatile formation and dissolution of a conductive filament in a solid electrolyte. Especially, Ag-doped chalcogenide glasses and thin films have become attractive materials for fundamental research of their structure, properties, and preparation. Ag-doped chalcogenide glasses have been used in the formation of solid electrolyte which is the active medium in ReRAM devices. In this paper, we investigated the nature of thin films formed by the photo-dissolution of Ag into Ge-Se glasses for use in ReRAM devices. These devices rely on ion transport in the film so produced to create electrically programmable resistance states [1-3]. We have demonstrated functionalities of Ag doped chalcogenide glasses based on their capabilities as solid electrolytes. Formation of such amorphous systems by the introduction of Ag+ ions photo-induced diffusion in thin chalcogenide films is considered. The influence of Ag+ ions is regarded in terms of diffusion kinetics and Ag saturation is related to the composition of the hosting material. Saturated Ag+ ions have been used in the formation of conductive filaments at the solid electrolyte which is the active medium in ReRAM devices. Following fabrication, the cell displays a metal-insulator-metal structure. We measured the I-V characteristics of a cell, similar results were obtained with different via sizes, due to the filamentary nature of resistance switching in ReRAM cell. As the voltage is swept from 0 V to a positive top electrode voltage, the device switches from a high resistive to a low resistive, or set. The low conducting, or reset, state can be restored by means of a negative voltage sweep where the switch-off of the device usually occurs.

• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.595-606
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• 2005

The scale of game development are rapidly increasing as the blockbuster games which cost $7\~20$ billion won, often appear on the markets. The game mechanics which is concentrated on technological elements of the game, necessarily requires the management of quality. In this paper, we propose a computer simulator for the quality evaluation of game mechanics which can analyze the quality accurately and economically in the design phase. The proposed simulator provides Petri net[7,8] and Smalltalk[9] for convenient modeling. The simulator gives the realistic evaluation like play test because it uses the realistic data of gameplay environment such as player action-pattern, game world map, and item DB but the previous evaluation methods can not consider the realistic gameplay environment and can only cover a limited scope of evaluation. To prove good performance of the proposed simulator, we have 80 simulations for the quality evaluation of the game mechanics of Dungeon & Dragon[13,14] in a given world map. The simulation results show that the proposed simulator can evaluate the faultlessness, optimization, and play balance of the game mechanics and gives better good performance than other evaluation methods.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.155-155
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• 2017

Surface modifications are commonly utilized to adjust the properties of the titanium and its alloy surface to the specific needs of the medical applications, but there are disadvantages such as poor osteoconductive properties and low adhesion of bone cell to implant surface. In order to improve these disadvantages, changes in surface properties have an important effect on osseointegration during implantation. In this paper we applied new technological method for improving a unique surface modification using the characteristic of an electrolytic Solution. Thus, in the electrolyte containing NaF in Na2SO4, TiO2 nanoporous was uniformly formed, and HAp nanoparticles were electrodeposited around the TiO2 nanopores, but in the electrolyte containing NH4F in (NH4)H2PO4, the coarse protrusions including HAp nano particles were regularly deposited onto the TiO2 barrier layer. The surface characteristics and the distributed elements and have been investigated by EDS analysis, and ultra-fine structure of surface are carried out using FE-SEM. To investigate the behavior of the anion, the analysis of chemical states was performed by XPS, and the narrow spectrums for Ti2P, Ca 2p, and P 2p seems to be almost similar depending on the characteristics of the electrolyte solution respectively. In addition, Ca 2p spectrum could be resolved into two peaks for Ca 2p3/2 and 2p1/2 at 347.4 and 351.3 eV, which are related to hydroxyapatite. And, the P peak can also be deconvoluted into two peaks for P1/2 and P3/2 levels with binding energy 134.2 and 133.4 eV, respectively. From the result of soaking test, the apatite morphologys were well-formed onto the modified surface according to the different conditions.

• Science of Emotion and Sensibility
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• v.10 no.4
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• pp.555-569
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• 2007

Ubiquitous computing environment is the new surroundings, currently being realized by modern technology. Since previous usability tests are not suitable for this new technological environment, new research on psychological factors needs to be conducted. The evaluation of service scenarios also will be required in tandem with traditional usability tests of operation devices. Consequently, this study classified usability factors from a scenario perspective and was conducted with a focus on the psychological elements of controllability from a mechanical perspective. Study 1 reclassified the factors of existing usability tests according to similarity and application scenarios, and ten important groups of factors were newly created. Study 2 focused specifically on the design side of a device and showed that the degree of familiarity with the ubiquitous computing device and its complexity brought about a difference in perceived controllability of the device.

• Journal of Science of Art and Design
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• v.8
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• pp.185-210
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• 2005

Closely connecting Well-Being culture with our traditional eating culture. we can predict next generation Kimchi refrigerator trend with this research. In the highly developing industrial society, design has been playing the central role in the managerial strategy of a company and has been one of the central agendas in determining the economical competence of a country, and has also been regarded as a means to acquire sustainable superior competence. Thus, these trends suggest that the aesthetic value of product has become more important than its technological function. In this study we reviewed theoretically esthetic factors influencing the preference and the evaluation of a product and made a list of eight esthetic factors based on various referential studies which include simplicity, balance, unity, rhythm, style, novelty, typicality, and proportion. Also on the point of view of design, it is necessary to find out definitely the consumer preference frame the relationship among design preference design image design attribute. Will give you guidelines on which designers can select and design some more objective and reliable design factors, finding out the relation of cause and effect by which they can know what kind of product designs their consumers like and how the popular image which that product offer is composed of. We investigated the esthetic factors affecting consumers preferences and the basis for evaluating a product. Aimed at providing materials for developing product design by presenting an ,esthetic guideline product design by presenting an esthetic guideline and to put these materials to practical use. Investigated other considered elements classified by manufactures and importance of esthetic factors and its influence on consumer tastes . All of these result, It could not conclude all of the adjective design image and design factors of every consumer, but through consumer reaction framework consumer are response and prefer the products which design image have. and then understand prefered design image are influenced to design factor's and could be apply to new design development.

• Science of Emotion and Sensibility
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• v.8 no.3
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• pp.203-212
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• 2005

In the highly developing industrial society the design has been playing the central role in the managerial strategy of a company and has been one of the central agendas in determining the economical competence of a country, and it is also regarded as a means to acquire sustainable superior competence And these trends suggest that the esthetic value of a product has become more important than the technological function. In this study we review theoretically esthetic factors influencing the preference of a product, so that we can make a list of eight esthetic factors based on the various referential studies. They are simplicity, balance, unity, rhythm, style, novelty, typicality, and proportion. We research esthetic factors affecting consumers' preferences and evaluation of a product and typical esthetic factors specific to the characteristics of each product. Therefore, in this study we tried to provide available materials in developing product design by present of esthetic guideline and to put this materials to practical use in product design by finding considered elements and importance of esthetic factors which had important effects on the tastes of the consumers classified by manufactures.