• Journal of the Korean Society for Precision Engineering
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• v.19 no.12
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• pp.78-85
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• 2002

The wavelet transform is a popular tool fer studying intermittent and localized phenomena in signals. In this study the wavelet transform of cutting force signals was conducted for the detection of a tool failure in turning process. We used the Daubechies wavelet analyzing function to detect a sudden change in cutting signal level. A preliminary stepped workpiece which had intentionally a hard condition was cut by the inserted cermet tool and a tool dynamometer obtained cutting force signals. From the results of the wavelet transform, the obtained signals were divided into approximation terms and detailed terms. At tool failure, the approximation signals were suddenly increased and the detailed signals were extremely oscillated just before tool failure.

• KSTLE International Journal
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• v.3 no.1
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• pp.17-22
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• 2002

Roughing of tool steel in its hardened state represents a real challenge in the die and meld industry and process improvement depends on research of tool material, coating technique, and lubrication. However, roughing of hardened steels generates extreme heat and without coolant flooding, tool material cannot withstand the high temperature without choosing the right tools with proper coating. This research conducted milling tests using coated ball end mills to study effects of cutting conditions and geometric parameters of ball end mills on the machinability of hardened tool steel. KP4 steel and STD 11 heat treated steels were used in the dry cutting as the workpiece and TiAIN coated ball end mills with side relief angle of 12$^{\circ}$ was utilized in the cutting tests. Cutting forces, tool wear, and surface roughness were measured in the cutting tests. Results from the experiments showed that 85 m/min of cutting speed and 0.32 mm/rev of feed rate were optimum conditions for better surface finish during rough cutting and 0.26mm/rev with the same cutting speed are optimum conditions in the finish cutting.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.5
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• pp.1-6
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• 2010

The wavelet transform is a popular tool for studying intermittent and localized phenomena in signals. In this study the wavelet transform of cutting force signals was conducted for the detection of a tool failure in turning process. We used the Daubechies wavelet analyzing function to detect a sudden change in cutting signal level. A preliminary stepped workpiece which had intentionally a hard condition was cut by the inserted cermet tool and a tool dynamometer obtained cutting force signals. From the results of the wavelet transform, the obtained signals were divided into approximation terms and detailed terms. At tool failure, the approximation signals were suddenly increased and the detailed signals were extremely oscillated just before tool failure.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.1
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• pp.90-99
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• 2021

Purpose: Nutrition screening is vital to ensure patients are appropriately managed in hospital. In paediatrics there is currently no universally accepted nutrition screening tool. The Nutrition Evaluation Screening Tool (NEST) was developed as an easy to use and practical screening tool for hospitalised children. We aim to evaluate compliance of the NEST and assess agreement of the NEST with the already validated nutrition screening tools, Screening Tool for Risk on Nutritional Status and Growth (STRONGkids), Screening Tool for the Assessment of Malnutrition in Paediatrics (STAMP) and the Subjective Global Nutritional Assessment (SGNA) tool. Methods: Retrospective review of 102 patient episodes at the Evelina London Children's Hospital. Electronic records were used to assess NEST compliance and to complete the nutrition tools for each patient episode. Cohen's kappa was used to determine the level of agreement between each nutrition tool. Results: There was moderate agreement between the NEST and the two screening tools, STRONGkids (κ=0.472) and STAMP (κ=0.416) for patients on initial screening at admission. 87.2% of patient episodes were NEST compliant within 24 hours of admission to hospital. Conclusion: The moderate agreement between these two already validated screening tools enhances the NEST's validity as a paediatric screening tool. The NEST had the strongest correlation with the SGNA tool compared to other screening tools. The NEST is user friendly screening tool for hospitalised children.

• Korean Journal of Community Nutrition
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• v.8 no.3
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• pp.319-326
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• 2003

The purposes of this study were: a) to develop the a quality measurement tool for the contract-managed hospital foodservice, and b) to evaluate their performance with the developed quality measurement tool, and c) to verify the reliability and validity of the quality measurement tool. The developed quality measurement tool comprised two parts, which were foodservice management and medical nutrition care service. The foodservice management part was classified into six functional categories which were Menu, Procurement and Storage, Production and Distribution, Facility and Utility, Sanitation and Safety, and Management and Evaluation. The medical nutrition care service part indicated the medical nutrition care provided. Quality measurement tool had 91 standards and 324 indicators. The quality measurement tools were distributed to the hospital foodservice manager employed by the foodservice company. The 324 indicators were measured by foodservice manager on the 5-Likert-type scales, and then adapted to a 100 point scale. The SPSS Ver. 11.0 was used for statistical analysis. The categories whose scores were evaluated as being high were Procurement', General Sanitation', Personal sanitation' and Waste' and the categories whose scores were evaluated as being low were Diet Order Manual', Standard Recipe', Appropriateness (Facility and Utility)', Check (Facility and Utility)'and Information Management'. All the categories of medical nutrition service were evaluated as having seriously low scores. Therefore, it was necessary for the contract-managed hospital foodservice to improve its performance in the area of medical nutrition care service. For the verification of the developed quality measurement tool, the reliability obtained by calculating Cronbach's α was 0.8747, and the content validity was also proved by scrutiny of the modification of the Professional group's techniques. (Korean J Community Nutrition 8(3) : 319∼326, 2003)

• Korean Journal of Materials Research
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• v.18 no.12
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• pp.635-639
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• 2008

In this paper, experimental studies of the regrinding of tungsten carbide (WC-Co) tools for high-speed machining were conducted. Regrinding and a subsequent evaluation test were carried out for a flat endmill tool with diameters of 10 mm and 3 mm using a CNC five-axis tool grinder and a CNC three-axis machining center. Tool wear on the two types of endmill tools increased as the cutting length increased, and the tool wear was not influenced by the regrinding state. In case of the micro endmill with a tool diameter of 3 mm, the effective regrinding time was determined for a flank wear threshold of 0.3 mm considering the tool life according to cutting length. The tool lives of the 10 mm and 3 mm endmill tools were increased by 80% and 72%, respectively. This conclusion proves the Feasibility of the recycling of tungsten carbide materials in the high-speed machining of high-hardened materials for industrial applications.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.4
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• pp.55-64
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• 2001

In this study, hemisphere and cylindrical shapes were machined for different tool paths and machining conditions with ball endmill cutters. Tool deflection, cutting forces and shape accuracy were measured according to the inclination position of the sculptured surface. As the decreasing of inclination position angle, the tool deflection was increased due to the decreased cutting speed when the cutting edge is approaching toward the center. Tool deflection when upward cutting is obtained less than that of downward cutting and down-milling in upward cutting showed the least tool deflection for the sculptured surface. Roundness values were found in least roundness error when down-milling in upward cutting. It is obtained the very little difference between 90。and 45。 of inclination position angle. The best surface roughness value was obtained in upward up-milling and showed different tendency with tool deflection and cutting force. For down-milling, the cutting resistance of the side wall direction is larger than that of feed direction. Therefore, this phenomenon which is received over cutting resistance can be caused of chatter.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.85-91
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• 2013

The machinability of wear-resistible tungsten carbides and the tool wear behavior in machining of V30 and V50 tungsten carbides using PCD (Poly Crystalline Diamond) cutting tool was investigated to understand machining characteristics. This material is one of the difficult-to-cut materials in present, but their usage has been already broadened to every commercial applications such as mining tools, and impact resistant tools etc. Summary of the results are as follows. (1) Tool wear progression of PCD tools in turning of wear-resistible tungsten carbides were observed specially fast in primary cutting distance within 10m. (2) Three components of cutting resistance in this research were different in balance from the ordinary cutting such as that cutting of steel or cast iron. Those were expressed large value by order of thrust force, principal force, feed force. (3) If presume from viewpoint of high efficient cutting within this research, a proper cutting speed was 15m/min and a proper feed rate was 0.1mm/rev. In this case, it was found that the tool life of PCD tool was cutting distance until 230m approximately. (4) In cutting of wear-resistible tungsten carbides such as V30 and V50, it was recognized that the tool wear rate of V30 was very fast as compared with V50. (5) When the depth of cut was 0.1mm, there was no influence of the feed rate on the feed force. And the feed force tended to decrease as the cutting distance was long, because the tool was worn and the tool edge retreated. (6) It was observed that the tungsten carbides were adhered to the flank.

• Journal of Korean Academy of Nursing Administration
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• v.7 no.2
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• pp.285-300
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• 2001

To meet standards for high quality of care and satisfied customers, an evaluation tool about nursing care is necessary. And, We need to evaluate our practice continuously for the improvement in quality and outcomes. This study was intended to develop an evaluation tool about nursing care in NSICU, and was progressed of 3 steps; development, content validity verification and reliability verification. Data were obtained and analysed from Feb. To April, 2000. Development process of the study was as follows A preliminary list was made item by item on the basis of clinical Experience, literature review and patients' record review. Then the standards, criteria and indicators of preliminary evaluation tool were set by 5 clinical nursing panel, and their content validity was reviewed by 27 ICU nurses. Finally, an evaluation tool was developed and verified the reliability at c-university hospital located in Kwang-Ju. The results of this was as follows 1) The evaluation tool of this study developed 8 standards, 39 criterias and 106 indicators. The standards were divided into two dimensions. One was process dimension which contained 4 standards(26 criteria), The other was outcome dimension which contained 4 standards(13 criteria). 2) the Average content validity of the tool was 3.39 at standards, 3.55 at criteria and 3.51 at indicators. 3) Interrater reliability of the tool is r=.7993(p<.001) & internal consistency reliability ${\alpha}$ is .6031 4) Scores of NSICU Patients who participated in this study were 57 at total mean score, 58 at process mean score and 56 at outcome mean score The evaluation tool developed in this study seems to be useful in evaluation nursing practice appropriately for the improvement of nursing care in NSICU. I hope that this evaluation tool can be used effectively in NSICU as an intervention for the improvement of quality control.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.58-63
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• 1993

The charactistics of AE(Acoustic Emission) signal is related to cutting conditions, tool materials and tool geometry in metal cutting. The tool geometry change which is derived from tool wear affects the source of AE signal in machining process. The relationship between AE signal and tool wear was experimentally investigated. THe value of RMS(Root Mean Sequare) and Amplitude of AE signal were increased in tool wear condition. Also the high value of Count per Hit and Count vs. Frequency was observed in this condtion. As a result, tool wear can be effectively detected by AE signal during cutting operation.