• Journal of the Korean Society for Precision Engineering
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• v.8 no.1
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• pp.105-115
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• 1991

This paper describes an integrated CAD and CAPP system for prismatic parts of injection mold which generates a complete process plan automatically from CAD data of a part without human intervention. This system employs Auto CAD as a CAD model and GS-CAPP as an automatic process planning system for injection mold. The proposed CAD/CAPP system consists of three modules such as CAD data conversion module, manufacturing feature recognition module, and CAD/CAPP interface module. CAD data conversion module transforms design data of AutoCAD into three dimensional part data. Manufacturing feature recognition module extracts specific manufacturing features of a part using feature recognition rule base. Each feature can be recognized by combining geometry, position and size of the feature. CAD/CAPP interface module links manufacturing feature codes and other head data to automatic process planning system. The CAD/CAPP system can improve the efficiency of process planning activities and reduce the time required for process planning. This system can provide a basis for the development of part feature based design by analyzing manufacturing features.

• Journal of Auto-vehicle Safety Association
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• v.14 no.2
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• pp.51-56
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• 2022

This paper presents an Ground Segmentation algorithm to eliminate unnecessary Lidar Point Cloud Data (PCD) in an autonomous driving system. We consider Random Sample Consensus (Ransac) Algorithm to process lidar ground data. Ransac designates inlier and outlier to erase ground point cloud and classified PCD into two parts. Test results show removal of PCD from ground area by distinguishing inlier and outlier. The paper validates ground rejection algorithm in real time calculating the number of objects recognized by ground data compared to lidar raw data and ground segmented data based on the z-axis. Ground Segmentation is simulated by Robot Operating System (ROS) and an analysis of autonomous driving data is constructed by Matlab. The proposed algorithm can enhance performance of autonomous driving as misrecognizing circumstances are reduced.

• Journal of Auto-vehicle Safety Association
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• v.14 no.1
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• pp.39-44
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• 2022

This paper presents a development of throttle and brake controller for autonomous vehicle simulation environment. Most of 3D simulator control autonomous vehicle by throttle and brake command. Therefore additional longitudinal controller is required to calculate pedal input from desired acceleration. The controller consists of two parts, feedback controller and feedforward controller. The feedback controller is designed to compensate error between the actual acceleration and desired acceleration calculated from autonomous driving algorithm. The feedforward controller is designed for fast response and the output is determined by the actual vehicle speed and desired acceleration. To verify the performance of the controller, simulations were conducted for various scenarios, and it was confirmed that the controller can successfully follow the target acceleration.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.185-192
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• 2013

The purpose of this study is to set the relationship between each parts that forms the engine of an automobile based on the 3D visualization technology which is able to be learned according to the skill of the operator in the industry field and to recommend the auto parts using a task ontology. A visualization method was proposed by structuring the complex knowledge by signifying the link and the node in forms of a network and using SOM which can be shown in the form of 3 dimension. In addition, by using is-a Relationship-based hierarchical Taxonomy setting the relationship between each of the parts that forms the engine of an automobile, to allow a recommendation using a weighted value possible. By providing and placing the complex knowledge in the 3D space to the user for an opportunity of more realistic and intuitive navigation, when randomly selecting the automobile parts, it allows the recommendation of the parts having a close relationship with the corresponding parts for easy assembly and to know the importance of usage for the automobile parts without any special expertise.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.1
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• pp.11-19
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• 2002

This study described computer aided die design system for cold forging of non-axisymmetric parts such as gears and splines. To design the cold forging die, an integrated approach based on a rule-base system and commercial F. E. code were adopted. This system is implemented on the personal computer and its environment is a commercial CAD package named as Auto CAD. The system includes four modules. In the initial data input module, variables which are necessary to design of die are inputted by user and die material are selected from the database according to the variables. In the analysis and redesign module, stress distribution acting on the designed die is analyzed by commercial FEM code NISA II with elastic mode. If die failure predicted, the designed die would modified in four ways to prevent die failure in both states of stress free and pressurizing. The developed system provides useful date and powerful capabilities for die design of non-axisymmetric parts.

• Journal of Environmental Impact Assessment
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• v.20 no.3
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• pp.357-365
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• 2011

The QUAL2K has the same basic characteristics as the QUAL2E model, which has been widely used in stream water quality modeling; in QUAL2K, however, various functions are supplemented. The QUAL2Kw model uses a genetic algorithm(GA) for automatic calibration of QUAL2K, and it can search for optimum water quality parameters efficiently using the calculation results of the model. The QUAL2Kw model was applied to the Gangneung Namdaecheon River on the east side of the Korean Peninsula. Because of the effluents from the urban area, the middle and lower parts of the river are more polluted than the upper parts. Moreover, the hydraulic characteristics differ between the lower and upper parts of rivers. Thus, the river reaches were divided into seven parts, auto-calibration for the multiple reaches was performed using the function of the user-defined automatic calibration of the rates worksheets. Because GA parameters affect the optimal solution of the model, the impact of the GA parameters used in QUAL2Kw on the fitness of the model was analyzed. Sensitivity analysis of various factors, such as population size, crossover probability, crossover mode, strategy for mutation and elitism, mutation rate, and reproduction plan, were performed. Using the results of this sensitivity analysis, the optimum GA parameters were selected to achieve the best fitness value.

• Journal of IKEEE
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• v.14 no.3
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• pp.190-198
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• 2010

This paper describes a auto focus piezo actuator driver IC for portable digital camera. The 80[V] DC voltage is generated by a DC-DC converter and supplied to power of piezo moving control circuit. The voltage of piezo actuator needs range -20[V] to 80[V] proportional to 1[Vp-p] input control voltages. The dimensions and number of external parts are minimized in order to get a smaller hardware size. IIC(Inter-IC) interface logic is designed for data interface and it makes debugging easy, test for mass productions. The power consumption is around 40[mW] with supply voltage of 3.6[V]. This device has been fabricated in a 0.6[um] double poly, triple metal 100[V] BCD MOS process and whole chip size is 1600*1500 [$um^2$].

• Journal of the Ergonomics Society of Korea
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• v.34 no.4
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• pp.293-302
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• 2015

Objective: This study was performed to investigate the prevalence of musculoskeletal disorders in auto workers of a mission assembly plants. Background: Most studies of musculoskeletal disorders have used car assembly line workers as their participants. However, little research has been done on musculoskeletal disorders afflictions of mission assembly line workers. Method: Through a focus group interview with an ergonomist and a manager at a mission assembly plant site, a questionnaire was developed for musculoskeletal disorders. The questionnaire consisted of five parts, demographic factors, musculoskeletal disorder symptoms, and musculoskeletal disorder experiences; 137 workers participated in this survey. The surveys were analyzed by correlation and Chi-squared analysis. Results: Musculoskeletal disorder symptoms and serious pain were reported in the neck, shoulder, back, and fingers. These problems were statistically related to various demographic factors, such as age, stature, stretching, and work satisfaction. Conclusion: Treatment of musculoskeletal disorders should consider the workers' traits. If there is no specific cause of the pain, developing stretches and exercises before and after work should be applied to prevent musculoskeletal disorders. Application: The results of this study can be used to develop guidelines to prevent injury in auto workers at mission assembly plants.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.11
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• pp.54-59
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• 1999

In this paper, a generalized auto-regressive(AR) model is proposed for linear prediction based on adaptive spatio-temporal support region(ASTSR). The conventional AR model suffers from the drawback that the prediction error increases in the edge region because the rectangular support region of the edge does not satisfy the stationary assumption. Thus, the proposed approach puts an emphasis on the formulation of a spatio-temporally adaptive support region for the AR model, called ASTSR. The ASTSR consists of two parts: the adaptive spatial support region(ASSR) connected with edges and the adaptive temporal support region(ATSR) related to temporal discontinuities. The AR model based on ASTSR not only produces more accurate model parameters but also reduces the computational complexity in the motion picture restoration.

• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.412-426
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• 2023

Currently, pigs breed in Korea are LYD (Landrace × Yorkshire × Duroc) crossbred pigs. Pigs used as fresh meat are gilts and barrows. However, the current supply of pork is not satisfying Korean consumers. In addition, the comparison of carcasses between gilts and barrows only studies carcass weight, backfat thickness, or meat quality, and there are very few studies comparing carcass characteristics. The purpose of this study was to compare characteristics of 7 primal cuts of gilts and barrows as measured by AutoFom III. A total of 350,179 pigs were used, including 176,461 gilts and 173,718 barrows. Characteristics of seven primal cuts were measured using AutoFom III. In the case of carcass weight, there was no significant difference in grade 1+. For all other survey items except for grade 2, gilts showed significantly (p < 0.05) higher values. For all grades except for pork belly, amounts of the remaining six primal cuts were higher in gilts (all p < 0.05,). In addition, the ratio of intermuscular fat in the pork belly of barrows showed a higher value than that in the pork belly of gilts (p < 0.05). The amount of pork belly, which is the most popular among consumers in Korea, not only produced more production than gilts in barrows, but also showed a higher value than gilts in barrows for the ratio of intermuscular fat affecting taste. In summary, gilts produced higher yields than barrows in all parts except pork belly. For the production of only pork belly, barrows showed higher production than gilts.