• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.4 s.181
• /
• pp.99-108
• /
• 2006

Since mold industries are regarded as belonging to three types of bad business, capable young people are reluctant to work in this field. The industries are hard to employ skilled workers who have much experience and knowledge On the mold manufacturing. Thus, effective CAM systems are required for unskilled workers to create process plans and NC data for the manufacturing, and process plans play important roles in the downstream manufacturing processes, such as NC machining, polishing, and final assembly. This study proposes a decision support system that facilitates unskilled workers to easily select high quality NC-data, as well as to increase productivity. The proposed system is assumed to follow a CAM operation scenario that consists of next three steps: 1) identifying several process plans and enumerating feasible unit machining operations (UMOs) from material and part surface information, 2) creating all feasible NC-data based on UMOs using a commercial CAM system, 3) selecting the best NC data among the feasible NC data using four screening criteria, such as machining accuracy, machining allowance, cutting load, and processing time. A case study on the machining of a camera core mold is provided to demonstrate the proposed system.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2005.05a
• /
• pp.1101-1107
• /
• 2005

Mold industry has the difficulty to employ young people as the successors of the skilled workers, because it has been regarded as a 3D-jobs(dirty, difficult, and dangerous). To overcome this situation, thus, manufacturing technologies maintained in the factory should be systemized, and engineering systems should support unskilled workers to do their jobs without any difficulty. As a research of developing the supporting system, this study proposes a decision support system that facilitates unskilled workers to easily select high quality NC-data, as well as to increase productivity. The proposed system is assumed to follow a CAM operation scenario that consists of next three steps: 1) identifying several process plans and enumerating feasible unit machining operations (UMOs) from material and part surface information, 2) creating all feasible NC-data based on UMOs using a commercial CAM system, 3) selecting the best NC data among the feasible NC data using four screening criteria, such as machining accuracy, machining allowance, cutting load, and processing time. A case study on the machining of a camera core mold is provided to demonstrate the proposed system.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.1
• /
• pp.93-100
• /
• 2000

Die-casting burr due to casting process is removed by post-process for assembly and quality control of product. Though robot has been widely used for deburring job before, CNC exclusive machine is currently developed f3r high power, high speed machining and quick tool change. Deburring tool path with complex 3D curve type is defined to make out deburring NC program. But there is no efficient method to define it currently used methods with teaching probe on machine. In this study the efficient method to make out deburring NC program is developed. 5-axis digitizing machine is used to receive data of deburring path. And the post processor for NC program generation is developed in consideration of the machining conditions. The developed system is not dependent on the skill of operator and has the advantage to maintain the flexibility of job to modify NC program due to the wear of tool and aging of the die casting.

• International Journal of Precision Engineering and Manufacturing
• /
• v.1 no.1
• /
• pp.118-126
• /
• 2000

Die-casting burr to casting process is removed by post-process for assembly and quality control of product. Though robot has been widely used for deburring job before. CNC exclusive machine is currently developed for high power, high speed machining and quick tool change. Deburring tool path with complex 3D curve type is defined to make out deburring NC program. But there is no efficient method to define it currently used methods with teaching probe on machine. In this study the efficient method to make out deburring NC program is developed. 5-axis digitizing machine is used to receive data of deburring path. And the post process for NC program generation is developed in consideration of the machining conditions. The developed system is not dependent on the skill of operator and has the advantage to maintain the flexibility of job to modify NC program due to the wear of tool and aging of the die casting.

• Journal of Pharmacopuncture
• /
• v.26 no.4
• /
• pp.285-297
• /
• 2023

Objectives: The aim of this systematic review and meta-analysis is to assess and compare the effectiveness of manual therapy in alleviating infant crying, a common symptom of nocturnal crying (NC) and infantile colic (IC). Methods: Total effective rate, crying time and adverse events were used as outcome indicators. To assess the quality, the risk of bias was determined for each study by two authors, using the Cochrane Collaboration's risk of bias tool. RevMan 5.0 was used for data analysis. A total of 98 articles were identified from 6 electronic databases. Results: Among them, twenty-seven studies which included 13 NC and 14 IC were included. Meta-analysis showed favorable effects tuina therapy on total effective rate (TER) of NC (RR: 1.20 [95% CI 1.05 to 1.37], p = 0.007), chiropractic therapy on crying time change of IC (SMD: -0.83 [95% CI -1.61 to -0.06], p = 0.04) and massage on total crying time of IC (SMD: -0.86 [95% CI -1.09 to -0.63], p < 0.00001). This systematic review compares different manual therapies for the treatment of NC and IC. While tuina, chiropractic, and massage show results in alleviating symptoms, the overall evidence remains limited due to the low quality and heterogeneity of the included studies. Conclusion: Therefore, further high-quality research with unified control groups is needed to establish manual therapy as a recommended treatment option for NC and IC. Protocol registration number is CRD42022348143 01/08/2022.

• Journal of Computational Design and Engineering
• /
• v.2 no.4
• /
• pp.218-232
• /
• 2015

Piecewise linear (G01-based) tool paths generated by CAM systems lack $G_1$ and $G_2$ continuity. The discontinuity causes vibration and unnecessary hesitation during machining. To ensure efficient high-speed machining, a method to improve the continuity of the tool paths is required, such as B-spline fitting that approximates G01 paths with B-spline curves. Conventional B-spline fitting approaches cannot be directly used for tool path B-spline fitting, because they have shortages such as numerical instability, lack of chord error constraint, and lack of assurance of a usable result. Progressive and Iterative Approximation for Least Squares (LSPIA) is an efficient method for data fitting that solves the numerical instability problem. However, it does not consider chord errors and needs more work to ensure ironclad results for commercial applications. In this paper, we use LSPIA method incorporating Energy term (ELSPIA) to avoid the numerical instability, and lower chord errors by using stretching energy term. We implement several algorithm improvements, including (1) an improved technique for initial control point determination over Dominant Point Method, (2) an algorithm that updates foot point parameters as needed, (3) analysis of the degrees of freedom of control points to insert new control points only when needed, (4) chord error refinement using a similar ELSPIA method with the above enhancements. The proposed approach can generate a shape-preserving B-spline curve. Experiments with data analysis and machining tests are presented for verification of quality and efficiency. Comparisons with other known solutions are included to evaluate the worthiness of the proposed solution.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.1275-1278
• /
• 1997

Cutting process has been automated by progress of CNC and CAD/CAM, but polishing process has been depended on only experiential knowledge of expert. To automate the polishing pricess polishing robot with 2 degrees of freedom which is attached to a machining center with 3 degrees of freedom has been developed. this automatic polishing robot is able to keep the polishing tool normal on the curved surface of die to improve a performance of polishing. Polishing task for a curved surface die demands repetitive operation and high precision, but conventional control algorithm can not cope with the problem of disturbance such as a change of load. In this research, we develop robust controller using real time sliding mode algorithm. To obtain gain parameters of sliding model control input, the signal compression method is used to identify polishing robot system. To obtain an effect of 5 degrees of freedom motion, 5 axes NC data for polishing are divided into data of two types for 3 axis machining center and 2 axis polishing are divided into data of two types for 3 axis machining center and 2 axis polishing robot. To find an efficient polishing condition to obtain high quality, various experiments are carried out.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.7 s.172
• /
• pp.122-129
• /
• 2005

Shoe with leather upper such as safety and golf shoe requires a roughing process where the upper is roughed fur helping outsole to be cemented well. It is an important and basic process for production of leather shoe but is not automated yet. Thus, there are problems that the defect rate is high and the quality of roughed surface is not uniform. In order to solve such problems, the interest in automation of roughing process is being increased and this paper introduces CAM system for 5-axis automatic roughing machine as one part of automation of roughing process. The CAM system developed interpolates a B-spline curve using points measured from the Roughing Path Measurement System. The B-spline curve is used to generate the tool path and orientation data fer a roughing tool which has not only stiffness but also flexibility to rough the inclined surface efficiently. For productivity, the upper of shoe is machined by side of the roughing tool and tool offset is applied to the roughing tool for machining of inclined surface. The generated NC code was applied to 5-axis polishing machine for the test. The upper of shoe was roughed well along the roughing path data from CAM and the roughed surface was proper fur cementing of the outsole.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.6
• /
• pp.815-825
• /
• 2019

Objective: To effectively use corn stover resources as animal feed, the changes in microbial population and chemical composition of corn stover during field exposure, and their silage fermentation and in vitro digestibility were studied. Methods: Corn cultivars (Jintian, Jinnuo, and Xianyu) stovers from 4 random sections of the field were harvested at the preliminary dough stage of maturity on September 2, 2015. The corn stover exposed in the field for 0, 7, 15, 30, 60, 90, and 180 d, and their silages at 60 d of ensiling were used for the analysis of microbial population, chemical composition, fermentation quality, and in vitro digestibility. Data were analyzed with a completely randomized $3{\times}6$ [corn stover cultivar $(C){\times}exposure$ d (D)] factorial treatment design. Analysis of variance was performed using SAS ver. 9.0 software (SAS Institute Inc., Cary, NC, USA). Results: Aerobic bacteria were dominant population in fresh corn stover. After ensiling, the lactic acid bacteria (LAB) became the dominant bacteria, while other microbes decreased or dropped below the detection level. The crude protein (CP) and water-soluble carbohydrate (WSC) for fresh stover were 6.74% to 9.51% and 11.75% to 13.21% on a dry matter basis, respectively. After exposure, the CP and WSC contents decreased greatly. Fresh stover had a relatively low dry matter while high WSC content and LAB counts, producing silage of good quality, but the dry stover did not. Silage fermentation inhibited nutrient loss and improved the fermentation quality and in vitro digestibility. Conclusion: The results confirm that fresh corn stover has good ensiling characteristics and that it can produce silage of good quality.

• Health Policy and Management
• /
• v.28 no.2
• /
• pp.119-127
• /
• 2018

Background: This study aimed to examine (1) the patterns of online health information search with respect to seeking and scanning, and (2) how online search, along with eHealth literacy, predicts perceived information usefulness in the context of diet and weight control. Methods: Online survey was conducted with 299 adults from the consumer panel recruited for the purpose of quality assessment of the Korean National Health Information Portal in 2016. We conducted paired sample t-test and multiple logistic regression to address the research questions. Data analysis was performed using IBM SPSS Statistics ver. 24.0 (IBM Corp., Armonk, NY, USA) and SAS ver. 9.3 (SAS Institute Inc., Cary, NC, USA). Results: Of the respondents, 38.8% were 'high seek-high scanners,' 35.8% were 'low seek-low scanners,' 13.0% were 'high seek-low scanners,' and 12.4% were 'low seek-high scanners.' eHealth literacy was a significant, positive predictor of online information scanning (odds ratio [OR], 2.46; 95% confidence interval [CI], 1.41-4.29), but not for online information seeking (OR, 1.75; 95% CI, 1.00-3.05). With respect to perceived usefulness of online information seeking, online seeking (OR, 4.90; 95% CI, 2.19-11.00) and eHealth literacy (OR, 2.30; 95% CI, 1.11-4.75) were significant predictors. Perceived usefulness of online scanning had a significant association with online scanning (OR, 2.38; 95% CI, 1.08-5.22), but not with eHealth literacy. Conclusion: To increase the effectiveness of the health policy for online information search and related outcomes in the context of diet and weight control, it is important to develop education programs promoting eHealth literacy.