• Journal of the Korean Association of Geographic Information Studies
• /
• v.19 no.3
• /
• pp.61-74
• /
• 2016

The purpose of this paper is to analyze the relationship between the location of the epicenter of a medium-sized earthquake(magnitude 4.8) that occurred on January 20, 2007 in the Odaesan area with lineament features using a shaded relief map(1/25,000 scale) and satellite images from LANDSAT-8 and KOMPSAT-2. Previous studies have analyzed lineament features in tectonic settings primarily by examining two-dimensional satellite images and shaded relief maps. These methods, however, limit the application of the visual interpretation of relief features long considered as the major component of lineament extraction. To overcome some existing limitations of two-dimensional images, this study examined three-dimensional images, produced from a Digital Elevation Model and drainage network map, for lineament extraction. This approach reduces mapping errors introduced by visual interpretation. In addition, spline interpolation was conducted to produce density maps of lineament frequency, intersection, and length required to estimate the density of lineament at the epicenter of the earthquake. An algorithm was developed to compute the Value of the Relative Density(VRD) representing the relative density of lineament from the map. The VRD is the lineament density of each map grid divided by the maximum density value from the map. As such, it is a quantified value that indicates the concentration level of the lineament density across the area impacted by the earthquake. Using this algorithm, the VRD calculated at the earthquake epicenter using the lineament's frequency, intersection, and length density maps ranged from approximately 0.60(min) to 0.90(max). However, because there were differences in mapped images such as those for solar altitude and azimuth, the mean of VRD was used rather than those categorized by the images. The results show that the average frequency of VRD was approximately 0.85, which was 21% higher than the intersection and length of VRD, demonstrating the close relationship that exists between lineament and the epicenter. Therefore, it is concluded that the density map analysis described in this study, based on lineament extraction, is valid and can be used as a primary data analysis tool for earthquake research in the future.

• Journal of the Korean Society of Earth Science Education
• /
• v.10 no.2
• /
• pp.140-160
• /
• 2017

The purpose of this study was to develop computational thinking (CT) analysis tool that can be used to analyze CT practices; first, by defining what CT practices are, and then, by identifying which components of CT are reflected in STEAM classes. Exploring various kinds of CT practices, which can be identified while applying the proposed CT analysis tool for exemplary STEAM classes, is another goal of this study. Firstly, to answer the question of "What is CT in science education" and thereby to develop the proposed CT practice analysis tool, three types of published documents about CT definition as the main data in this study have been considered. In the first "analysis tool development" part of this study, the following five elements have been identified as the main components of CT analysis tool as follows; (1) connecting open problems with computing, (2) using tools or computers to develop computing artifact, (3) abstraction process, (4) analyzing and evaluating computing process and artifact, and (5) communicating and cooperating. Based on the understandings that there is a consistent flow among the five components due to their interactions, a flow chart of CT practice has also been developed. In the second part of this study, which is an implementation study, the proposed CT practice analysis tool has been applied in one exemplary STEAM program. To select the candidate STEAM program, four selection criteria have been identified. Then, the proposed CT practice analysis tool has been applied for the selected STEAM program to determine the degree of CT practice reflected in the program and furthermore, to suggest a way of improving the proposed CT analysis tool if it shows some weak points. Through the findings of this study, we suggest that the actual definition of computational thinking will be helpful to converge Technology and Engineering to STEAM education and a strong complement to reinforce STEAM education.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.4C
• /
• pp.247-254
• /
• 2006

Online testing method is one of the numerical experiment methods using experimental information for a numerical analysis directly. The method has an advantage in that analysis can be conducted without using an idealized mechanical model, because mechanical properties are updated from element test for a numerical analysis in real time. The online testing method has mainly been used for the geotechnical seismic engineering, whose major target is sand. A testing method that may be applied to a consolidation problem has recently been developed and laboratory and field verifications have been tried. Although related research thus far has mainly used a method to update average reaction for a numerical analysis by positioning an element tests at the center of a consolidation layer, a weakness that accuracy of the analysis can be impaired as the thickness of the consolidation layer becomes more thicker has been pointed out regarding the method. To clarify the effectiveness and possible analysis scope of the online testing method in relation to the consolidation problem, we need to review the results by applying experiment conditions that may completely exclude such a factor. This research reviewed the results of the online consolidation test in terms of reproduction of the consolidation settlement and the dissipation of excess pore water pressure of a clay specimen by comparing the results of an online consolidation test and a separated-type consolidation test carried out under the same conditions. As a result, the online consolidation test reproduced the change of compressibility according effective stress of clay without a huge contradiction. In terms of the dissipation rate of excess pore water pressure, however, the online consolidation test was a little faster. In conclusion, experiment procedure needs to improve in a direction that hydraulic conductivity can be updated in real time so as to more precisely predict the dissipation of excess pore water pressure. Further research or improvement should be carried out with regard to the consolidation settlement after the end of the dissipation of excess pore water pressure.

• Journal of the Korean Professional Engineers Association
• /
• v.28 no.4
• /
• pp.54-75
• /
• 1995

This synthesis has been prepared from a review of literature on Truck Escape Ramps technology and a survey of current practice by state department of transportation. Their locations have been determined usually from a combination of accident experience and en-gineering judgement, but new tools are emerging that can identify needs and sites without waiting for catastrophic accidents to happen. The Grade Severity Rating Systems holds promise in this regard. Design Procedures for truck excape ramps continue to evolve. Gravel arrester beds are clearly the preferred choice across the country Rounded aggregate, uniformly graded in the approximate size range of 13 to 18mm. Tech-nical publications typically have dassified TER types as paved gravity, sandpile, and ar-rester bed ramps. The design speed for vehicle entry into the ramp in critical to the deter-mination of ramp length. An escape ramp should be designed for a minimum entry speed of 130km/hr, a 145km/hr design being preferred. The ramps should be straight and their angle to the roadway align-ment should be as possible. The grade of truck escape ramps show the adjustment of ramp design to local topography, such as the tradeoff of ramp length against earthwork requirements. A width of 9 to 12m would more safety acommodate two or more outof con-trol vehicles. Reguarding comments on the most effective material, most respondents cited their own specification or referred to single graded, rounded pea gravel. The consensus essentially Is that single graded, well -rounded gravel is the most desirable material for use in arrester beds. The arrester beds should be constructed with a minimum aggregate depth of 30cm. Successful ramps have used depths between 30 and 90cm.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.63 no.4
• /
• pp.273-281
• /
• 2018

Wet hill seeding (WHS) is one of the more famous labor and money saving methods technology used for rice cultivation. In WHS, rice standing percentage and weedy rice occurrence are the most important factors considered to secure a rice yield. We investigated the optimum seeding date of WHS in the Southern Plain area of South Korea. Weedy rice needed two weeks at $15^{\circ}C$ to show over 80% emergence. Germinated rice seed grown at $20^{\circ}C$ needed over for 10 days to achieve a shoot length over 3 cm. In field cultivation, the mean temperature for ten days after seeding showed a highly positive correlation with rice standing rate, spikelet number per square meter and yield index that favorably compared to machine transplanting. With these data, we suggest that the optimum seeding date of WHS that can secure over 98% of yield index of machine transplanting in Southern part of Korea is May. 21~Jun. 5 in Honam and May. 16~Jun. 5 in Yeongnam area.

• Journal of Venture Innovation
• /
• v.7 no.1
• /
• pp.131-149
• /
• 2024

This study was important considering the prevalence of small business owners in the Korean economy and the challenges they faced amidst an economic downturn. The business performance of these owners was crucial for their survival. Thus, an empirical analysis was conducted to identify factors influencing their management performance. The analysis included personal characteristics of small business owners such as innovativeness, management capability, need for achievement, and technical capability as independent variables, along with product differentiation factors. Additionally, the moderating effect of social capital on these variables and their impact on management performance was tested. To achieve this, a survey targeting small business owners across Korea was conducted, and data from 250 respondents were utilized. Hierarchical regression analysis using SPSS 24.0 was employed for the empirical analysis. The results indicated that management capability, need for achievement, and product differentiation significantly positively impacted business performance. However, the impact of innovativeness and technical capability was not tested. The influence of the variables on business performance ranked as follows: product differentiation, management capability, and need for achievement. The moderating effect of social capital was significant in the relationship between management capability, need for achievement, and management performance, enhancing these relationships. However, the moderating effect of social capital on the relationship between innovativeness, technical capability, product differentiation, and management performance was not tested. These findings underscored the importance of management capability, need for achievement, and product differentiation as key factors affecting the management performance of Korean small businesses. This study was significant as it provided insights into improving the management performance of small business owners in challenging economic conditions by highlighting how the influence of these factors varied depending on the social capital possessed by the owners.

• Journal of the Korean Orthopaedic Association
• /
• v.54 no.4
• /
• pp.343-352
• /
• 2019

Purpose: The purpose of this study was to document the sonographic morphology of the subscapularis footprint, particularly the 1st facet, of the non-pathologic subscapularis tendon and footprint, and analyze the correlation between the size of the 1st facet and the demographic variables. Materials and Methods: Between March 2015 and December 2017, retrospectively data analysis was performed for the ultrasound (US) scans of 115 consecutive shoulder (mean age 53.4 years, range 23-74 years) with non-pathologic subscapularis tendon and footprint. The sonographic findings of the 1st facet of the subscapularis footprint was a very unique, flat, broad, and plane angle in the upward direction, which were distinguished from the other facets. On US, the transverse (medio-lateral) and longitudinal (superior-inferior) length of the 1st facet on axis of the humerus shaft were recorded. The demographic variables, including age, site, body height, weight, body mass index (BMI), and arm length, were reviewed. Results: On US, the mean transverse length of the 1st facet was 12.75 mm (range 10.54-14.50 mm, standard deviation [SD] 0.712) and the mean longitudinal length was 12.22 mm (range 9.20-13.30 mm, SD 0.888). The transverse and longitudinal length of the size of the 1st facet were significantly greater in males than in females (p<0.001, p=0.001). Of the demographic data (body height, weight, BMI, arm length) that showed a significant positive linear correlation, the correlation with body height (transverse r=0.749, p<0.001; longitudinal r=0.642, p<0.001) showed the strongest relationship, and the correlation with the BMI was weakly related. The relationships between the size of the 1st facet to site/age were not statistically significant or appeared to have no linear correlation. Conclusion: The structural and morphologic features of the 1st facet of the subscapularis footprint on the US were identified. This will provide anatomic knowledge of an US examination for subscapularis tendon pathology.

• Korean Journal of Construction Engineering and Management
• /
• v.13 no.6
• /
• pp.13-23
• /
• 2012

While Category 1 and Category 2 bridges are intensively inspected and carefully managed, many small bridges that are not in the Category 1 and 2 are often forgotten until they decay in serious condition. Since many of these small bridges located in the populated city, failure of them would cause huge negative impact on the community. This paper focuses on the small size concrete bridges for timely repair and rehabilitation work for the effective operation and management. Test bed is developed to define the key parameters to forecast the long term performance of the bridges, mostly concrete box bridges. Key parameters suggested in this paper are cumulative fatigue due to repetitive heavy traffic loads and the acid attacks for concrete material deterioration. The cumulative fatigue is measured by the use of the mileage concept. For the long term data collection and inspection, stable and easy to use data collection system is installed as a test bed. The contribution of this research work is on the development of the test bed to define the key parameters of bridge deterioration.

• The Journal of Society for e-Business Studies
• /
• v.15 no.2
• /
• pp.137-166
• /
• 2010

A virtual team is defined a group of people that use electronic communications for some or all of their interactions with other team members. Because team members of a virtual team are physically and temporally distributed, a team's transactive memory system(TMS) is considered to be crucial for the team's effectiveness and performance. TMS refers to a set of individual memory systems which integrate knowledge possessed by particular members through a shared awareness of who knows what. This paper seeks to understand (1) how a virtual team's TMS influences team performance, and (2) what factors contribute to developing the team's TMS. Given these purposes, through the extensive literature review, we first identified components and antecedents to develop a theoretical model that predicts a virtual team's performance. Using the survey data gathered from 172 virtual teams, this study found that expertise location, coordination, and cognition-based trust which were proposed as three components of TMS positively influenced a virtual team's performance. Furthermore, this study uncovered that perceived media richness, network tie strength, and shared norms significantly influenced the components of TMS, while geographical dispersion did not exert any significant influence on TMS.

• Journal of the HCI Society of Korea
• /
• v.12 no.4
• /
• pp.27-35
• /
• 2017

This study aims to investigate the influence of engagement of augmented reality game on immersion. The relationship between engagement and flow was examined through the mediating effects of emotional attachment and focus of attention on presence and the mediating effects of presence on flow. In order to verify the research hypothesis, online questionnaire was conducted with the consent of $Pok\acute{e}mon$ Go game user group. The questionnaire items were translated from the Augmented Reality Immersion Questionnaire. A total of 200 questionnaires were collected and used for analysis. Using the SPSS 23.0 program and the Mplus 7.0 program, the reliability of the scale was confirmed through the Cronbach's coefficient and the causal relationship and the mediating effects were verified by path analysis. As a result, there was no direct causal relationship between engagement and flow. However, causal relationship was evident when emotional attachment and focus of attention were mediated in the process of engagement in augmented reality game. In conclusion, systematic explanations of participant's emotional attachment and attentional state as a main factor in the process of participating in the augmented reality game involvement, reveal the elements to be noticed by the augmented reality game.