• Journal of the Korean earth science society
• /
• v.27 no.3
• /
• pp.269-278
• /
• 2006

In this study, we used Virtual Reality (VR) materials on an introductory earth science course consisted of thirty six pre-service science teacher program students. Before and after class an instrument of Constructivist Learning Environment Survey (CLES) was administered. The main focus of the CLES was to evaluate how the classroom was prepared for student centered learning environment. The pre and post tests of student perceptions regarding their learning environment were compared in six domains: personal relevance, critical voice, shared control, student negotiation, scientific uncertainty, and attitude. Questionnaire regarding the general perception of the VR materials was administered as well. How future science teachers valued the use of VR materials in their classrooms was found from this study. Based on these results, we intend to contribute for a more complete understanding of the potential of VR materials in achieving better learner-centered classroom environment.

• Journal of Communications and Networks
• /
• v.18 no.2
• /
• pp.182-189
• /
• 2016

The focus in this paper is on obtaining tight, simple algebraic-form bounds and invertible expressions for the average symbol error probability (ASEP) of M-ary phase shift keying (MPSK) in a class of composite fading channels. We employ the mixture gamma (MG) distribution to approximate the signal-to-noise ratio (SNR) distributions of fading models, which include Nakagami-m, Generalized-K ($K_G$), and Nakagami-lognormal fading as specific examples. Our approach involves using the tight upper and lower bounds that we recently derived on the Gaussian Q-function, which can easily be averaged over the general MG distribution. First, algebraic-form upper bounds are derived on the ASEP of MPSK for M > 2, based on the union upper bound on the symbol error probability (SEP) of MPSK in additive white Gaussian noise (AWGN) given by a single Gaussian Q-function. By comparison with the exact ASEP results obtained by numerical integration, we show that these upper bounds are extremely tight for all SNR values of practical interest. These bounds can be employed as accurate approximations that are invertible for high SNR. For the special case of binary phase shift keying (BPSK) (M = 2), where the exact SEP in the AWGN channel is given as one Gaussian Q-function, upper and lower bounds on the exact ASEP are obtained. The bounds can be made arbitrarily tight by adjusting the parameters in our Gaussian bounds. The average of the upper and lower bounds gives a very accurate approximation of the exact ASEP. Moreover, the arbitrarily accurate approximations for all three of the fading models we consider become invertible for reasonably high SNR.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.2
• /
• pp.273-284
• /
• 2015

The feasibility conditions of interference alignment (IA) are analyzed for reverse duplex systems, in which one cell operates as downlink (DL) while the other cell operates as uplink (UL) assuming one-sid base station (BS) cooperation. Under general multiple-input and multiple-output (MIMO) antenna configurations, a necessary condition and a sufficient condition for one-shot linear IA are established, i.e., linear IA without symbol or time extension. In several example networks, optimal sum degrees of freedom (DoF) is characterized by the derived necessary condition and sufficient condition. For some special class of networks, a sufficient condition is established in a more compact expression, which also yields the necessary and sufficient condition. Simulation results demonstrate that the proposed IA does not only achieve larger DoF but also significantly improves the sum rate in the practical signal-to-noise ratio (SNR) regime.

• Journal of the Korean Institute of Educational Facilities
• /
• v.21 no.3
• /
• pp.29-36
• /
• 2014

Properties of school foundation are divided into fundamental property for education and fundamental property for profit. As school sites and teachers used for educational and study activities of students, fundamental property for education includes practice sites, farms and support research attached facilities in addition to school facilities. According to the Clause 1 of Article 4 of the University Foundation and Management Regulation and the Attached Table 2 of the Same Regulation, dormitory is classified as property for education(non-profit). In other words, there is no need to create profit for dormitory management. It is supposed that there are little regional differences in construction cost of dormitory with general specifications. In this case, boarding fees of university dormitories should make no difference. This study analyzed boarding fees, depending on regional factors(Seoul, Gyeonggi-do, metropolitan cities and provinces), and depending on foundation subjects(national public university and private university), classes(four-year university and college) and principal schools-branch schools. The result of One-Way ANOVA showed that Seoul showed the highest average boarding fee and it was followed by Gyeonggi-do, metropolitan cities and provinces. Also, the average boarding fees of private universities and four-year universities were higher than national public universities and than colleges, respectively. In addition, branch school's boarding fee was higher than principal school's. Additionally, this study extracted a model using the hedonic model to see how various characteristics such as region, foundation subject and class influence the boarding fee. This study would serve as fundamental research on the boarding fee. Thus far, there have been difficulties in obtaining accurate data and analyzing boarding fees, since there is no open data about dormitories and it isn't mandatory to open it, but it is anticipated that this would be used as fundamental research for estimating and analyzing boarding fees of many universities in the future.

• Journal of Korean Elementary Science Education
• /
• v.23 no.1
• /
• pp.44-49
• /
• 2004

This study was based upon the survey on the name of 13 basic experimental instruments used in elementary science class: Schale, evaporating dish, mortar & pestle, beaker, erlenmeyer flask, spuit(medicine dropper), graduated cylinder, balance, spatula, dropping bottle, gas collecting bottle, funnel, alcohol burner, and their uses. To implement this study, an open-ended, written questionnaire was administered to the subjects of in-service elementary school teachers, future elementary teachers who have attended at the Gyeongin national university of education, and elementary students in Korea. The findings of this study were as follows: The rates of in-service and pre-service elementary school teachers that knew correct name of experimental instruments were not high, the elementary school student's rates were especially very low. In this study, we found several reasons which they wrote inaccurately: the name to be represented at the textbook that they had studied, the confusion of the name about a fortis pronunciation, the recognition as the vocabulary like flask and cylinder to be meaningless, the habit to say in an everyday life, wrong expression in the internet and general book. All respondents had a wide range of perceptions of uses for the experimental instruments. Their understanding of uses for evaporating dish, erlenmeyer flask, balance, gas collecting bottle were very poor. And then most of them understood that graduated cylinder, beaker, and erlenmeyer flask were tools to measure the volume of solution or liquid, so they did not exactly distinguish the difference of their uses.

• Korean Institute of Interior Design Journal
• /
• v.24 no.5
• /
• pp.51-61
• /
• 2015

The purposes of this study were to examine the characteristics of elements composing the cultural identity of Chinese architectural and spatial design, and to analyze the expression characteristics and influencing factors of contemporary restaurant design. With these purposes, first, this study reviewed related literature in order to find the characteristics of tangible elements observed in intangible elements and space expression characteristics forming the cultural identity of China. Second, this study conducted a case study in order to understand the expression characteristics of the design of Chinese restaurants in Shanghai and to find factors influencing the design. In order to sample the subjects of the case study, the researcher selected 18 restaurants that were recommended repeatedly in books on Chinese restaurants and tourism and major Internet sites or highly evaluated by visitors, and then choose 15 of them that were found to be fit for the purpose of the survey. According to the result of the survey, the restaurants were largely grouped by type into 10 cases of fine dining, 3 of middle-class casual dining, 1 of fast food, and 1 of luxury tea house serving traditional tea and snacks. Of these restaurants, 46.7% (7 cases) were of CM-CM-CM type, namely, using contemporary simple elements in all of external spaces, indoor spaces, and decorations, 20% (3 cases) were of CM-CM-CT type, using contemporary and simple external and indoor spaces, and traditional furniture or articles, 20% (3 cases) were of CT-CM-CT type, using traditional external spaces such as traditional buildings, contemporary simple finishing of indoor spaces, and traditional articles such as palace lanterns and traditional doors and windows, and 13.3% (2 cases) were of CT-CT-CT type, using traditional elements in their original forms in general. Through this research and survey, cultural identity showing Chinese traditions observed in the expression characteristics of restaurant spatial designs was confirmed, and it was also found that the identity was underlain by ideologies, values, lifestyles, etc. that had long accumulated through the long history of the country and exerted a great influence.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.29 no.1
• /
• pp.92-99
• /
• 2001

This study analyzed the effects of illumination on psychological accessibility from a view of satisfaction of night use at urban neighborhood park for actual night users. For this, we have classified the effects of illumination as five sampled independent variables from 12 effects of illumination, and tested the relationship with satisfaction of night use of a dependent variable by multiple regression analysis. The results of this study are as follows; 1) The effects of illumination for night use at urban neighborhood park were divided into five factors; (1) direct effect, (2) effect of promoting use, (3) effect of ensuring security, (4) effect of preparing landscape in the night time, and (5) psychological effect. Among independent variables indicating characteristics of effects of each illumination, uneasiness at night use was high. 2) In a multiple regression model, when other conditions were not changed, the value of security of night use (X\ulcorner) had maximumly an affect on the value of dependent. And, the value of danger to meet the depraved(X\ulcorner) had minimally an affect on the value of dependent variable. 3) For the contribution of security of nigh use(X\ulcorner) and brightness of present using space(X$_4$) to satisfaction of night use(Y) of dependent variable, they had a nearly equal effect on that, and showed about 2 times importance compared to familiarity with park(X\ulcorner) and the beauty of park(X\ulcorner). Also, they showed about 7 times contribution to satisfaction of night use compared to danger to meet the depraved(X\ulcorner), which had minimally an affect on the value of dependent variable, as the most important variables. 4) For the effects of illumination on satisfaction of night use, the effect of ensuring security - pursues security of park for the general rather than security for the specific class or subject - and direct effect to offer proper brightness in using space relatively affected on it much compared to psychological effect, effect of preparing landscape in night time, and effect of promoting use. A research on the psychological effects among the variables related to illumination as well as physical circumstances such as the height, location, direction of illumination should be studied.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.29 no.4
• /
• pp.44-52
• /
• 2001

This study performed factor analysis for 21 independent variables related to the effect of illumination and suggested the effect by multiple regression analysis on the relationship between the effect of illumination and the satisfaction of use of a dependent variable to find the effect of illumination in urban parks at night and the effect of illumination on the satisfaction of use. The results of this study are as follows; 1) Of the 21 independent variables used to study the effect of illumination in urban parks at night, the impact on safety and possibility of crime was highly. The effects of illumination by factor analysis were abstracted as effects of removing anxiety, securing safety, increasing use. 2) As a result of multiple regression analysis, independent variables influencing satisfaction of use in urban park were proved as effects of removing anxiety, securing safety, increasing identity, preparing atmosphere and increasing use. Also, the effect of securing safety was the most important factor; it showed a level of importance 2 times higher than the effect of removing anxiety, and 7.7 times higher than the effect of preparing atmosphere in relative contribution of the effect of illumination to satisfaction of use. 3) Of the effects of illumination influencing satisfaction of use in urban parks, the effect of securing safety and the effect of increasing visibility were more significant than the effects of removing anxiety, preparing atmosphere and increasing use. This fact means that personal safety an the identity of persons or facilities in the space of use should be considered with priority in planning or designing illumination. Also, it implies hat, for night use in urban parks, lightness of the space is required for general safety of use at parks, and proper illuminance on the activity in the space of use should be required. The subject parks of this study are 8 urban neighborhood parks. The model on the effect of illumination and the satisfaction of use depends on characteristics and conditions of location of he park and user class, so the subject parks and persons should be varied, and the difference by sex or ages should be suggested.

• Journal of Energy Engineering
• /
• v.26 no.1
• /
• pp.34-44
• /
• 2017

This paper deals with the effectiveness of a fiber optic solar lighting system that uses a Fresnel lens mounted on a two-axis solar tracker. A series of comparative analyses were made concerning its performance as compared to fluorescent lighting by using a simulation model based on ECOTECT and RADIANCE as well as referring to actual data. ECOTECT was used to model the test room (space) while RADIANCE was used for its indoor lighting conditions (environment). It was found that the average indoor light levels of fluorescent lighting fully satisfy the KS standard (KS A 3011, general office, class [G]: 300-400-600lux) whereas those of the solar lighting with light diffusers depends on the occlusion factor of roller shades installed on the south window.

• Journal of Engineering Education Research
• /
• v.12 no.3
• /
• pp.118-128
• /
• 2009

The purpose of this study is to develop a teaching and learning model for the field of engineering to nurture innovative thinking and competency in engineering elites of the next generation. We have reviewed the literature to find out the necessary thinking and capabilities required for the next-generation engineers, and analyzing domestic and international case studies. As a result, we have created Scientific Inquiry and Creative Activity with Technology (SICAT) as a teaching and learning model applicable for the Fusion Materials field. SICAT model is classified ARDA, CoCD, ReSh type to apply directly in class according to teaching and learning objective. And we developed SICAT teaching and learning model guidebook for teachers. In near future, It should be consolidated the validity of the model and improved succeedingly in engineering education through applying and analyzing effectiveness in classes.