• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1999년도 유체기계 연구개발 발표회 논문집
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• pp.109-113
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• 1999

Thermal mass flow meter (TMF) is used measuring the small mass flow rate of gases. Generally, flow rate measuring accuracy of TMF is $\pm2{\%}$ of full scale. TMF is manufactured for specified working pressure and specified working gas by customer. If it were applied for different working pressure and gases, flow rate measurement accuracy decreased dramatically. In this study, a TMF tested with three different gases and pressure range of 0.2 MPa to 1.0 MPa. Effect of specific heat cause to increase flow measurement error as much as ratio of specific heat compare with reference gas. Pressure change cause to increase flowrate measurement deviation about $-0.2{\%}$ as the working pressure decreased 0.1 MPa.

• Restorative Dentistry and Endodontics
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• 제31권1호
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• pp.30-35
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• 2006

만곡근관에서 근관형성방법에 따른 근관작업장 변화를 평가하기 위하여 발거된 대구치의 협측 또는 근심 근관 40개에서 스테인레스-스틸 수동 파일 ($MANI^{(R)}$, 일본), 니켈-티타늄 수동 파일 (Naviflex $NT^{TM}$, 미국), ProFile, 또는 $ProTaper^{TM}$ (Dentsply-Maillefor, 스위스)를 사용하여 crown-down 방법으로 30번 크기까지 근관을 형성하고 근관형성 전후의 근관작업장 및 만곡도의 변화를 관찰하였다. 근단공에 대한 10-K파일 끝의 위치변화를 AutoCAD2000 (Autodesk 사, 미국)으로 측정하고 일원변량분석법 및 Tukey's studentized range test로 통계 분석하였다. 모든 군에서 근관형성후 근관장 및 만곡도가 유의하게 감소하였으며, 치관부 근관형성시 Gates Glidden bur를 사용한 수동파일 군이 ProFile 군보다 유의하게 많은 근관장 감소를 초래하였고, 치관부 및 근단부 전체 근관형성후에는 스테인레스 스틸 수동파일 군이 ProFile 군에서보다 유의하게 많은 근관장 감소를 나타내었다 (p<0.05).

• 임상간호연구
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• 제20권2호
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• pp.189-199
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• 2014

Purpose: The purpose of this study was to investigate job stress and job satisfaction among nurses in gastrointestinal endoscopy units, and factors related to their job stress and job satisfaction. Methods: The study participants were 153 nurses working in gastrointestinal endoscopy units at eleven general hospitals. Job stress and job satisfaction were measured using nurses's job stress scale and the index of work satisfaction respectively. Results: The average job stress was 3.67 (range 1~5) and job satisfaction was 2.90 (range 1~5). Gastrointestinal endoscopy unit nurses, who were full time worker, having more than 7 years of clinical experiences, having higher incomes, having high subjective work-intensity, and having an intention to change their working units, showed greater job stresses than those of the others. There were significant differences in job satisfaction according to subjective health status, the types of employment, subjective work-intensity, subjective aptitude, intention to change working units, major nursing tasks, and the numbers of major nursing tasks. Also, the subjects's job stress showed a negative correlation with job satisfaction. Conclusion: Findings suggest that management strategies should be developed to increase job satisfaction focusing on general and job characteristics associated with job stress.

• 대한산업공학회지
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• 제41권6호
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• pp.551-558
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• 2015

The purpose of this paper is to investigate the development of mechanical projectile transfer system to prevent musculoskeletal problems in the firing test range. Prior to 2010, the projectile has been transferred from the worktable to the loading device of 155mm K9 fixed-type artillery by manual. Because the amount of firing test has been increased drastically since 2010, two types of mechanical projectile transfer system were developed to prevent musculoskeletal problems. The NIOSH lift equation and the working posture assessment system such as OWAS, RULA and REBA were used to evaluate the appropriacy of working weight and posture by manual transfer of projectile. The configuration and operation procedure of projectile transfer systems which were developed to improve work efficacy and to reduce the burden of manual transferring were described. The improvements were assessed by the number of processes, the tact time and the working posture assessment for operation of this system by comparing to the manual transfer of projectile.

• Bulletin of the Korean Chemical Society
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• 제29권9호
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• pp.1742-1746
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• 2008

Catechol and caffeine were simultaneously analyzed with a bismuth-immobilized carbon nanotube paste electrode (BPE) using square wave (SW) stripping voltammetry. Optimum analytical conditions were determined. Simultaneous working ranges of 100-1,500 $mgL^{-1}$ for caffeine and 5-75 $mgL^{-1}$ for catechol were obtained. In the separated cell systems, a working range of 0.1-2.1 $mgL^{-1}$ catechol with a correlation coefficient of 0.9935, and a working range of 10-210 $mgL^{-1}$ caffeine with a correlation coefficient of 0.9921 were obtained. A detection limit (S/N) of 0.15 $mgL^{-1}$ (7.7 ${\times}$ $10^{-7}$ M) and a detection limit of 0.02 $mgL^{-1}$ (1.82 ${\times}$ $10^{-7}$ M), respectively, manifested for catechol and caffeine. It was found that three macro-type electrode systems could be implanted in fish and rat neuro cells. For both ions, the ion currents were observed. The physiological impulse conditions and the neuronal thinking current were also obtained.

• Current Optics and Photonics
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• 제7권4호
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• pp.398-407
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• 2023

We explored a method to evaluate imaging performance for the optimal assembly of an endoscopic miniature lens and a sensor constituting an imaging module at the distal end of gastrointestinal endoscopy. For the assembly of the imaging module, the image sensor was precisely located at the focal plane when collimated light passed through the endoscopic lens. As another method, the distance between the lens and sensor was adjusted to obtain the highest focus index from images measured the star chart of the International Organization for Standardization (ISO) standard at various positions. We analyzed the slanted-edge modulation transfer function (MTF), corresponding depth of field, and number of line pairs for MTF 50% and 20% at each working distance within the range of 5-100 mm for imaging modules assembled in different ways. Assembly conditions of the imaging module with better MTF performance were defined for each working distance range of 5-30 mm and 30-100 mm, respectively. In addition to the MTF performance, the focus index of each assembled module was also compared. In summary, we examined the performance of imaging modules assembled with different methods within the suggested working distance and tried to establish the optimal assembly protocol.

• Journal of Advanced Marine Engineering and Technology
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• 제22권6호
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• pp.792-799
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• 1998

Further improvement of existing $H_{2}O/LiBr$ absorption refrigeration machine is absolutely neces-sary to promote the utilization of gas-cooling system Among various methods to improve the per-formance of the absorption refrigeration machine this research has focused on the use of a new working fluid that has better properties than the existing $H_{2}O/LiBr$ working fluid. In the series of the research, $H_{2}O/LiBr+HO{(CH_{2})}_{3}OH$ system was selected as the most promisable candidate. The absorption refrigeration machine is water-cooled double-effect, $H_{2}O/LiBr+HO{(CH_{2})}_{3}OH$ sys-tem with series flow type. In this study we found out the characteristic of new working solution through the cycle simulation and compared the result with that of LiBr solution to evaluate. Theoptimum designs and operating conditions were determined based on the operating constraints and the coefficient of performance. Results demonstrate that new working fluid subsrantially increases COP by as much as 10% and has a wider working range with 8% higher crystallization limits compared to the conventional $H_{2}O/LiBr$.

• KSBB Journal
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• 제13권5호
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• pp.491-496
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• 1998

The production of fibrinolytic enzyme from Bacillus subtilis BK-17 was studied in the shake flask cultures. The important medium components studied include nitrogen source, carbon source and inorganic salts. The environmental conditions include initial pH, temperature, shaking speed and working volume. Among various N-sources, C-sources and inorganic salts tested, soybean flour, D-glucose and Na2HPO4 gave the best results, and their optimal concentrations were 1.5%, 0.5% and 0.05%, respectively. The optimal pH and temperature were 9.0 and 37$^{\circ}C$. With decreasing working volume in the range of 25∼100ml in the 250ml flask or increasing shaking speed in the range of 100∼300rpm, the enzyme production was greatly enhanced. The enzyme activity under the optimal conditions was about 1400I.U./ml with urokinase as a standard.

• 전기화학회지
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• 제6권2호
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• pp.158-160
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• 2003

We have reported to make nanostructured cobalt oxide electrode that have large capacitance over than 400 F/g (specific capacitance) and good cycleability. But, it had serious demerits of low voltage range under 0.5 V and low power density. Therefore, we need to increase voltage range of cobalt oxide electrode. We report here on the electrochemical properties of sol-gel-derived nanoparticulate cobalt xerogel in 1M KOH solution and aqueous polymeric gel electrolyte. In solution electrolyte, cobalt oxide electrode had over 250 F/g capacitance consisted of EDLC and pseudocapacitance. In gel electrolyte, cobalt oxide electrode had around 100 F/g capacitance. This capacitance was only electric double layer capacitance of active surface area. In solution electrolyte, potassium ion as working ion reacted with both of layers easily. However, In gel electrolyte, reacted with only surface-active layer. Itis very hard to reach resistive layer. So, we have studied on pretreatment of electrode to contain working ions easily. We'll report more details.

• 한국응용과학기술학회지
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• 제28권4호
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• pp.502-507
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• 2011

A voltammetric assay of phenol ions was investigated using three electrode systems of graphite pencil working, reference and counter electrodes. Under optimum analytical parameters, square wave stripping working ranges were attained at a mili range of 10~80 mg/L and a micro range of 20~90 ug/L using seawater electrolyte. The developed sensor was applied to tap water and the human body system of a smoker. It was found that the methods can be applied to in vivo fluid or medicinal diagnosis.