• 한국기계가공학회지
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• 제4권1호
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• pp.18-23
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• 2005

This paper reports experimental results on microdrilling process for silicon parts used in semiconductor equipments. An experimental system was developed consisting of a high speed precision machine, microscope system, and project profile instrument. The experimental results indicate that the amount of chipping at the entrance and exit of micro hole decreases as the spindle speed increases up to 18,000 rpm. At higher spindle speed, however, the amount of chipping increases rapidly. The amount of chipping and infeed rate show proportional relationship up to 20 m/min of infeed rate. Beyond that infeed rate, however, sudden increase in the amount of chipping has occurred.

• 약학회지
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• 제39권2호
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• pp.148-152
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• 1995

For comparison between the compromised experimental condition and the best conditions for each element by flame atomic absorption spectrometer, the absorbances were measured with changing the burner height and HCL current. The optimum absorbance for simultaneous analysis of 6 elements was observed at 1 mA of HCL current and at 4 mm of burner height except Cr and Co. The stability of flame atomic absorption spectrometer on each element was found to be better than 5%. To investigated the accuracy of this instrument, POSCO RM-07 as a real sample was analysed at these compromised experimental conditions and found to be better than 0.04%.

• 아동학회지
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• 제21권2호
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• pp.45-56
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• 2000

This study investigated the effects of writing activity integrated with verbal sharing on the diversity of vocabulary and complexity of expression in 33 five-year-old children attending a private kindergarten in Seoul. Subjects were divided into a control group of 16 children and an experimental group of 17 children. The experimental group participated in a 7 week program of writing activities integrated with verbal sharing time. The instrument used for the pre-and post-tests was the writing ability test(Nam Mi Jung, 1996) and the complexity of sentences test(Young Hee No, 1994). Data were analyzed by ANCOVA. The results revealed significant differences between the experimental and control groups in children's diversity of vocabulary and complexity of expression.

• Structural Engineering and Mechanics
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• 제40권6호
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• pp.801-811
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• 2011

A new experimental technique was developed on the plate-inserted welded tubular joints of spatial grid structures. In the experimental technique, a microcomputer controlling instrument of moire intervention (MCIMI) was adopted. A test was designed on the plate-inserted welded tubular joints of spatial grid structures to show the effectiveness of the MCIMI technique. Both traditional electrical measuring technique and MCIMI technique were employed in the test. The test results showed that the MCIMI technique was feasible in the case of the complicated tests on steel structures. The MCIMI technique not only implemented the limitation of traditional electrical measuring technique, but also improved the accuracy of the test. According to the test results, we further examined the plate-inserted welded tubular joints in the cable-stayed spatial grids of the Binhai International Convention & Exhibition in Tianjin, China. The analysis showed the joints are safely designed with adequate conservatism. The research provided a new application of MCIMI in the field of large-scale structure engineering.

• Restorative Dentistry and Endodontics
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• 제24권3호
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• pp.503-510
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• 1999

The purpose of this study was to evaluate the amount of transportation of original canal, zip formation, permanent deformation and fracture of instruments after canal enlargement. In this study, the 60 resin blocks that have curved canals were randomly divided into 3 experimental groups with 20 teeth each according to instrument types and filling methods for canal enlargement. The curved canals of each experimental groups were enlarged to No 40 ISO size with the K-flexo stainless steel file (Group 1), Engine-driven Ni-Ti Profile new series(Group 2) and Engine-driven Ni-Ti Quantec 2000 series(Group 3) according to the manufacturer's recommendation. Pre- and postoperative X-rays were taken at same position and the films were scanned and the canal images were traced to determine the canal curvature according to the method of Schneider. The amount of reduction in canal curvature were calculated between pre- and postoperative X-rays. In addition to zip formation, permanent deformation and fracture of instruments were examined after canal enlargement. The results were as follows : 1. All experimental groups showed some loss of canal curvature after instrumentation. There was a significant change in curvature between before and after instrumentation in each group(p<0.001). 2. Engine-driven Ni-Ti instrumentations resulted in an average loss of curvature of 2.36 degrees for Profile new series, 3.43 degrees for Quantec series, and hand instrumentation showed an average loss of curvature of 6.48 degrees for K-flexo file. There was a statistical significant difference between hand instrumentation and engine-driven Ni-Ti instrumentations(p<0.05). But there was no statistical difference between Profile new series and Quantec series. 3. There were many apical zip formations in group 1(Hand instrumentation). But there were no apical zip formations in group 2,3(Engine-driven Ni-Ti instrumentation). 4. The instrument deformation occured 9 cases in group 1(K-flexo file), 2 cases in group 2(Profile new series) and 3 cases in group 3(Quantec) after instrumentation. And the instrument fracture occured 1 case in each group. The results showed that the engine-driven Ni-Ti instruments, if we use carefully according to manufacturer's recommendations, can be use effectively for instrumenting the curved root canals in case of the MAF was over size 40.

• Advances in Energy Research
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• 제5권3호
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• pp.255-275
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• 2017

The advantages of using natural circulation (NC) as a cooling system, has prompted the worldwide development to investigate this phenomenon more than before. The interesting application of the NC in low power experimental facilities and research reactors, highlights the obligation of study in these laminar flows. The inherent oscillations of NC between hot source and cold sink in low Grashof numbers necessitates stability analysis of cooling flow with experimental or numerical schemes. For this type of analysis, numerical methods could be implemented to desired mass, momentum and energy equations as an efficient instrument for predicting the behavior of the flow field. In this work, using the explicit, implicit and Crank-Nicolson methods, the fluid flow parameters in a natural circulation experimental test loop are obtained and the sensitivity of solving approaches are discussed. In this way, at first, the steady state and transient results from explicit are obtained and compared with experimental data. The implicit and crank-Nicolson scheme is investigated in next steps and in subsequent this research is focused on the numerical aspects of instability prediction for these schemes. In the following, the assessment of the flow behavior with coarse and fine mesh sizes and time-steps has been reported and the numerical schemes convergence are compared. For more detail research, the natural circulation of fluid was modeled by ANSYS-CFX software and results for the experimental loop are shown. Finally, the stability map for rectangular closed loop was obtained with employing the Nyquist criterion.

• 기본간호학회지
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• 제7권2호
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• pp.177-191
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• 2000

The purpose of this study to conform the effect of the aseptic dressing method to prevent infusion phlebitis. One quaxi-experimental, nonequvalent control group post-test design was used to evaluate prevention of phlebitis between a control group and an experimental group. The data for the control group were collected from 100 hospitalized patients from July 1 to November 30, 1999. The data for the experimental group were collected from 100 hospitalized patients from December 1, 1999 to March 5, 2000. The control group used paper tape on the IV site and the experimental group used a sterile gauze dressing which was changed every 24 hours. Two sets of instruments were used for this study. First, instrument developed Weinstein(1993) and modified by the researcher was used for judging phlebitis. The second, instrument developed Park(1996) was used for assessment records concerning the phlebitis which developed. Catheter sites were inspected on a daily basis by unit nurses and development of phlebitis was grade and documented. Data were analyzed using $x^2-test$ and stepwise regression The results are summarized as follows : 1. The incidence of phlebitis according to the duration of catheter insertion decreased in the experimental group($x^2=3.56$, p<.05). 2. The incidence of phlebitis according to the duration of catheter insertion decreased in the experimental group($x^2=28.79$, P<.0001). 3. No significant difference was found between the experimental and control groups in the severity of phlebitis. 4. A statistically significant difference between the two groups was found in the incidence of phlebitis according to the location of the insertion site. 5. No statistically significant difference between two groups was found in the incidence of phlebitis by age 6. A statistically significant difference between two groups was found in the incidence of phlebitis by sex($x^2=3.88$, p<.05) 7. Further study revealed that the duration of catheter and sex were predictors of occurrence of the phlebitis, explaining 38.2%, 14.2% of the total variance respectively. In conclusion, the aseptic dressing method is recommended to be prevent infusion phlebitis.

• Journal of the Korean Statistical Society
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• 제22권2호
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• pp.219-234
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• 1993

A measuring instrument must be calibrated for accurate inferences of an unknown quantity. Bayesian calibration designs with respect to squared error loss based on a linear model are discussed in Kim and Barlow (1992). In this paper, we consider approximations of the optimal calibration designs using the idea of Gaussian inflence diagrams. The approximation is evaluated by means of numerical calculations, where it is compared with the exact values from the numerical integration.

• 구강회복응용과학지
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• 제22권2호
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• pp.173-180
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• 2006

Objectives The aim of this study is to compare the quality of root canal preparation completed using MFile-$System^{(R)}$ instrument ( Komet, Gebr.Brsaseler, Germany) and conventional stainless steel file in the canals of Maxillary molar teeth that had a canal curvature between $25^{\circ}$ or more Materials & Methods Buccal canals of 24 first and second maxillary molar teeth, extracted for periodontal and prosthetic reasons were used. Tissue fragments and calcified debris were removed from teeth by scaling and the teeth were stored in 10% formalin solution for 24 hour. Then, teeth were stored in saline until used. To be included the roots had to have completed formed apices and angle of curvature ranging between $25^{\circ}$ or more according to the criteria described by Schneider(1971). Palatal and Second mesiobuccal canals were not included. Teeth were embedded into transparent acrylic. The teeth were randomly divided into two experimental groups. All teeth were scanned by Dental CT (PSR9000N, Asahi, Japan) to determine the root canal shape before instrumentation. Image slices were prepared from the apical end point to the pulp chamber. The first two sections were 2 mm from the apical end of root and 2 mm below the orifice. Further section was recorded, dividing the distance between the sections of apical and coronal levels into two equal lengths. 12 teeth were instrumented using stainless steel fileand another 12 teeth were instrumented using MFile-$System^{(R)}$. Following the completion of the instrumentation, the teeth were again scanned and compared with the cross sectional images taken prior to canal preparation. Amount of transportation and centering ability was assessed. Student's t-test was used for statistical analysis. Result Less transportation occurred with MFile-$System^{(R)}$ rotary instrumentation than stainless steel instrument. MFile-$System^{(R)}$ had better centering ability than stainless steel instrument. Conclusion MFile-$System^{(R)}$ rotary instrumentation transported canals less and had good centering ability.

• 동의신경정신과학회지
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• 제23권4호
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• pp.133-152
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• 2012

Objectives : The purpose of this study is to investigate the effect of Sihogayonggolmoryeo-tang on the anxiety of Hwa-byung. Methods : In this randomized, double blinded, placebo-controlled study, we planned to give Sihogayonggolmoryeo-tang or controlled medication for anxiety of Hwa-byung. Hamilton Anxiety Scale (HAM-A) was measured as the 1st evaluative instrument, and Korean State-Trait Anxiety Inventory (STAI-K), Likert scale for major symptom of Hwa-byung, Hwa-Byung Scale Score, Korean Beck's Depression Inventory (BDI-K), Korean State-Trait Anger Expression Inventory (STAXI-K), Insomnia severity Index (ISI), Instrument of Oriental Medical Evaluation for Hwa-Byung, WHO Quality of Life Avvreviated (WHOQOL-BREF), genral self-Efficacy Scale (GSES), Rosenberg Self-Esteem Inventory (SRE) and Heart Rate Variability (HRV) were also measured as the 2nd evaluative instrument before treatment. Results : Clinical characteristics-vital signs and demographic characteristics showed no significant difference between both groups. The characteristics of disease-chief complaint, pattern Identification, period, etiological factor, and etc, also showed similarity of distribution in both groups. The results of Chest PA, EKG and clinicopathologic examination showed no significant difference between both groups. There were no significant difference between both groups in all valuation scales; HAM-A was measured as the first evaluative instrument, and STAI-K, Likert scale for major symptom of Hwa-byung, Hwa-Byung Scale Score, BDI-K, STAXI-K, ISI, Instrument of Oriental Medical Evaluation for Hwa-Byung, WHOQOL-BREF, GSES, SRE and HRV. Conclusions : We considered that establishment of the experimental group and controlled group was objective and worth conducting this research. In addition, this methodology is expected to be applied to the subsequent research. Further, we hope to make up for this study through various study and discussion.