• Journal of the Korea Computer Graphics Society
• /
• v.18 no.1
• /
• pp.29-34
• /
• 2012

High-quality tetrahedral meshes are crucial for FEM-based simulation of large elasto-plastic deformation and tetrahedral-mesh-based simulation of fluid flow. This paper proposes a volume meshing method that exploits an octree-based adaptive signed distance field to fill the inside of a polygonal object with tetrahedra, of which dihedral angles are good. The suggested method utilizes an octree structure to reduce the total number of tetrahedra by space-efficiently filling an object with graded tetrahedra. To obtain a high-quality mesh with good dihedral angles, we restrict the octree in such a way that any pair of neighboring cells only differs by one level. In octree-based tetrahedral meshing, the signed distance computation of a point to the surface of a given object is a very important and frequently-called operation. To accelerate this operation, we develop a method that computes a signed distance field directly on the vertices of the octree cells while constructing the octree using a top-down approach. This is the main focus of the paper. The suggested tetrahedral meshing method is fast, stable and easy to implement.

• Journal of Korean Library and Information Science Society
• /
• v.49 no.3
• /
• pp.429-458
• /
• 2018

In this study, based on the results of analyzing the facilities and operation of the public libraries in Iksan, several strategies that may contribute to its regional development have been established. The strategies are as follows. The first one is to hire more librarians to perform the role of libraries at the advanced level that are suitable for the ever-growing library facilities. The second is the plan for specialization of the libraries, which was proposed with each subject suitable for each library such as History Culture, Modern and Local Culture, Jewelry and Precious metal, Food Cluster, Female, Administration & Welfare, and Environment & Ecology by matching the urban policies and characteristics of Iksan with these library. The others are the operation of English library in the way suggested in this study and the establishment of youth library to build up the role of the libraries in educational city. Through these strategies, the overall function and role of the public libraries in Iksan can be strengthened and emphasized.

• Journal of KIISE:Databases
• /
• v.30 no.1
• /
• pp.27-40
• /
• 2003

The inverted index widely used in the existing information retrieval field should be extended for XML documents to support containment queries by XML information retrieval systems. In this paper, we consider that there are two methods in storing the inverted index and processing containment queries for XML documents as the previous work suggested: using a RDBMS or using an inverted lift engine. It has two drawbacks to extend the inverted index in the previous work. One is that using a RDBMS is moth worse in the performance than using an inverted list engine. The other is that when containment queries are processed in a RDBMS, there is an increase in the number of a join operation as the path length of a query increases and a join operation always happens between large fables. In this paper. we extend the inverted index in a different way to solve these problems and show the effectiveness of using a RDBMS.

• Korean Journal of Poultry Science
• /
• v.18 no.1
• /
• pp.57-66
• /
• 1991

The broiler industry in Korea has been gradually changing its structure of independent operation into integrated and coordinated production and marketing system. It was in 1960s when the broiler industry first tried the integrated effort, but never succeeded as it was expected since due mainly to growers' attitudes favorable for traditional operation and agribusiness' passive response on structure change. Until mid 1980s, however, a bit of partially integrated system had been evolved by several factor suppliers. Recent years have furthered its progress toward completely integrated pattern, the ultimate goal of broiler integration. It is true that the external factors including the GATT Negotiations through the Uruguay Round stimulated the people involved in the industry to find the way of making it competitive to survive in the open, liberalized world economic system rapidly emerging through the process of globalization. Once the industry realized the necessity of reducing the cost of production and improving the quality of it, the conclusion tended to come to the point of an entire structural alteration by means of integration rather than an improvement of a certain segment such as marketing. It is very obvious. therefore. that the movement toward the complete integration will speed up in a coming few years under the leadership of not only entrepreneurs but also producers group. According to a report. there were three almost complete integrators and thirteen partial integrators as of December, 1990, all of which eagerly directed toward the completely integrated system in due course . Among others as an advantage of integrated structure. the cost saving must be pointed out as the greatest one In a survey, it was estimated that the cost of dressed and ready-to-eat chicken could be lowered by 31.8 percent and 41.5 percent, respectively, over that to be under the independent, non-integrated system. As long as everybody concerned about the future of the industry in the open market mechanism realizes the importance of the structure change through an integration, the broiler sector of Korean agriculture shall be moving toward the direction of vertically and completely integrated structure in order to make it competitive, even to export, hopefully before 1995 or by the end of this century in any case.

• Convergence Security Journal
• /
• v.16 no.6_1
• /
• pp.25-32
• /
• 2016

We can not respond asymmetric warfare effectively. The asymmetric operation is performed in asymmetric methods and means with different characteristics and functions to their enemy. And the character of the asymmetric operation have 'heterogeneity' and 'superiority' in principle. The type of asymmetric strategy is complex and diverse. Since we can classify the type of the asymmetric strategy in many different way and we must study in many ways and aspects. When we study asymmetric war previous cases from modern to ancient era, we can find that the key factors of the victory have superiority of the asymmetric strategy and discriminatory measures. The asymmetry is created when one party has to adapt to the strategic environment. If we want to secure a strategic advantage, we must take a number of case studies and countermeasures for asymmetric warfare.

• KIPS Transactions on Computer and Communication Systems
• /
• v.1 no.3
• /
• pp.171-180
• /
• 2012

In the development of MDMS(Meter Data Management System) based on CIM(Common Information Model), which is international standard in information model and data exchange on power system, the two focused issues are the effective management of data collected in a shorter time period and the way to integrate services supporting legacy system to use the AMI(AMI, Advanced Metering Infrastructure) data. In this paper, we propose MDMS implementation methods and functions in AMI environment which are differ from existing AMR system environments in that the methods support bi-directional service infrastructure. The proposed MDMS in this paper has two unique features, one is the secure of interoperability by utilizing the CIM and ESB, the other is the improvement of field application by implementing system module based on components. On an implementation of smart grid, the result of proposed methods is expected to contribute to the efficient development and operation of CIM-based power system.

• International Journal of Highway Engineering
• /
• v.15 no.5
• /
• pp.217-226
• /
• 2013

PURPOSES : Under the capacity conditions with balanced approach flows, roundabouts give less delay than existing signalized intersections; however, flows over 450 vehicles/hour/lane with unbalanced approach flow conditions, roundabouts efficiency drops due to the short time difference between the critical gap and the follow-up headway. The purpose of this study is developing a roundabout Signal Metering operation method by considering approach lanes degree of saturation. METHODS : A four-way-approach with one-lane roundabout is selected to compare the Signal Metering performance for the case of 16 different unbalanced flow conditions. Based on these traffic conditions, the performance is evaluated for 64 different cases of Signal Metering combinations by using SIDRA software. A degree of saturation(V/C ratio) sum for two adjoined approaches is used for the performance index of choosing Metered Approach and Controlling Approach. RESULTS : When the V/C ratio sum is 0.29~0.81 and Metered Approach flow is less than Controlling Approach flow, the average delay saving per vehicle is about 7 seconds; however, after this rage the delay saving decreases gradually until the V/C ratio sum reaches around 1.0. The range of V/C ratio sum 0.93~1.09 provides average delay saving per vehicle about 3 seconds. In case of V/C ratio sum is grater than 1.0 and the flows of Metered Approach is grater than Controlling Approach, the average delay per vehicle increases 3~11 times respectively. CONCLUSIONS : As expected, the Signal Metering provides substantial improvements in delay saving for the case of V/C ratio sum is 0.3~1.0 under the traffic flow conditions of Metered Approach is less than Controlling Approach.

• Korean Journal of Applied Biomechanics
• /
• v.28 no.4
• /
• pp.199-205
• /
• 2018

Objective: The purpose of this study was to examine the effect of increase in barbell weight on closely related variable to the anterior cruciate ligament (ACL) injury which are knee joint kinematics, joint load, joint moment, and maximum load attainment point during snatch of the weight lifting. Method: The subjects of the study were 10 male Korean national weight lifting athletes (69 kg 5, 77 kg 5; age: $21.80{\pm}3.91yrs.$, height: $168.00{\pm}4.06cm$, weight: $75.00{\pm}4.02kg$, career: $7.8{\pm}3.99yrs.$, snatch records: $168{\pm}4.06kg$). The weight of the barbell during the snatch operation was set at 70%, 75% and 80% of the highest records for each subject studied. Results: The result obtained from the one-way repeated measure ANOVA are as follows: With increased barbell weight, the extension moment of the left knee joint was higher in the 80% condition than the 70% (p<.001). However, other variables were not statistically significant difference. According to the factor analysis of the variables related to maximum load attainment point of the ACL major injury variables, the first sub-factor was the internal shear force, the posterior shear force, the abduction moment, and the muscle activity of the VL. The second sub-factor was the extension moment of the knee joint, compressive force, adduction moment, and the third sub-factor was the muscle activity of BF. Conclusion: These results indicate that the possibility of ACL injury can be lowered when performing a stable snatch movement.

• Journal of The Korean Association For Science Education
• /
• v.43 no.1
• /
• pp.29-36
• /
• 2023

This study investigates the effects of the operation of science activity program on scientific literacy focusing on science cultural literacy and core competencies for pre-service teachers. 255 pre-service teachers of K University participated, and the effects of the program were examined through a paired-sample t-test with one group pretest-posttest design for science cultural literacy. Only the post-test was conducted on core competency growth perception, and differences in growth perceptions by competency were compared using ANOVA. As a result of the study, the average of pre-service teachers was higher than the pre-test for science culture literacy, and this difference was statistically significant (p<.05). In the core competency growth perception, 70.6% of pre-service teachers reported growth in scientific communication ability, and as a result of the post-hoc test using LSD, it shows statistically significant growth compared to other competencies (p<.05). Through this, it was possible to confirm the educational value of the science activity program as a way to develop pre-service teachers' scientific literacy.

• Plant Journal
• /
• v.18 no.4
• /
• pp.48-57
• /
• 2023

In this study, I discussed a way of the improved operation criteria to detect combustion instability in advance F-Class Gas Turbine, which adopts lean pre-mixed combustion system. The data of 16 blades path temperature thermocouple installed radially at the gas Turbine exit were collected to analyze the variation of individual blade path temperature. The cumulative variation in individual blade path temperature for one week under normal combustion conditions was confirmed to be up to 26℃. On the other hand, in the event of combustion instability, the symptoms of increased temperature variations in the individual thermocouple were mostly seen from a few days ago. Based on the results of this study, it is deemed appropriate to inspect and maintain in Ulsan Thermal Power Gas Turbine when the individual blade path temperature exceeds 50℃ of the cumulative variation for 10 days.