• Journal of Pharmaceutical Investigation
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• v.41 no.1
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• pp.25-30
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• 2011

Recently, Korean Food and Drug Administration (KFDA) has focused on developing quality control guidelines for all commercial products in Korea to enforce regulations, improve the quality control, and protect consumers by developing prevalently used and efficient analytical tools to determine and quantify target compounds. Because the Korean Pharmacopeia (KP) presents microbiological assays for biotin, which is laborious and time-consuming, this study is focused on applying HPLC-UV to detect and quantify biotin in complex drugs and dietary supplements like multi-vitamin. Biotin in complex drugs was extracted from methanol and analyzed using mobile phase with 10 mM potassium phosphate (monobasic, pH=3.0) in distilled water and acetonitrile. Gradient condition was used to successfully detect and quantify biotin within 20 minutes. Validation result for linearity was significant that average $r^2$ was 0.999 (n=3) and its relative standard deviation (RSD) was 0.0578% which was less than 2%. Using this method, quantification of biotin in complex drugs was completed successfully and recovery tests were finished that recovery percentage greater than 95% with relative standard deviation less than 2%.

• Journal of Korean Academy of Nursing Administration
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• v.12 no.4
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• pp.541-554
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• 2006

Purpose: The purpose of this study is to provide basic data for the improvement of the quality in the emergency nursing services by investigating the expectation level and actual received level with nursing care and identifying the factors that influence patient satisfaction with the emergency nursing care in the military hospitals. Method: Using a self report questionnaire, data were collected from 150 patients who had been admitted in military hospitals emergency department. The data collection was done between April 17 and April 30, 2006. At least, 145 questionnaires were analyzed and used in this study. Results: The average sum score was 61.93 out of 76 with standard deviation 9.590. The mean of the patient's expectation levels with the overall emergency nursing services was $(3.25{\pm}.504)$ out of the highest score 4. the average sum score was 63.27 out of 76 with standard deviation 9.902. The mean score of the patient's actual levels with the overall emergency nursing services was $(3.33{\pm}.521)$ out of the highest score 4. Conclusion: nursing management strategies must be established to remove patient's dissatisfaction factors and to improve the emergency nursing care quality through continuous measurement and assessment of the patient's satisfaction with emergency nursing services in military hospitals.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.1
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• pp.92-97
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• 2007

This study was carried out to minimize the lifting force and to design the slim sized frame of a height adjustment mechanism. This unit is designed for the display devices in order to enhance the ergonomics for effective height adjustment as well as to achieve much slimmer frame for the pedestal. A tolerance analysis of 6 sigma was applied to achieve smooth lift at design stage not to change the tolerance specification of gap several times in a roller type of lifting mechanism at mass production stage. The specification of minimum gap and the target of production yield ratio were agreed with a quality team before tooling. A DFSS simulation on drawings had been done with reasonable tolerance and achievable standard deviation(${\sigma}$) several times until the target specification of gap and yield ratio was met. Once tolerance and deviation(${\sigma}$) were fixed tooling start was done successfully. A CAE method was applied to achieve a slim design. Design parameters were frozen when those parameters matched the reference strength data of standard model. Through those tolerance analysis and CAE simulation the number of tool modification was reduced and production yield ratio was raised up without arguing quality specification at production stage in the end.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.1006-1012
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• 2010

The hot rolling process ranks the highest position for production in steel making process. The hot strip manufacturing processes consist of the reheating furnace, roughing and finishing mill and coiler. The reheating furnace heats the slab. The roughing and finishing mill produce the hot strip from slab. The hot strip quality mainly depends on finishing mill, which consists of 4-high 7 stands. The looper is installed between stands and is used for controlling the strip tension by the looper angle for better material flow. It is difficult to control the strip tension with the coupled looper system from interaction between the looper angle and strip tension. Too much deviation of strip tension severely affects the poor width quality of the hot strip. It is important to control simultaneously both the looper angle and strip tension with each of their target values. This paper proposes the fuzzy tension control, which is developed to minimize the width deviation of the hot strip by maintaining the proper strip tension between stands and to achieve the stable operation of the coupled looper system. The fuzzy tension control performance is compared with the conventional PID control by experimental results.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.11
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• pp.995-1000
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• 2010

With the development of the auto industry, the automobile manufacturers demand to shorten development period and reduce the cost. Compared with the traditional method, applying the virtual prototype is more economical. This paper presents a method for parameters sensitivity analysis and optimizing the performance of vehicle noise and vibration. The existing design processes were repeatedly analyzed with a focus on vehicle performance to decide the design parameters of dimension, thickness, mounting type of body and chassis systems in the vehicle development period. This paper describes the prediction technique of vehicle performance using L18 orthogonal array layout, quality deviation analysis and parameter sensitivity analysis for robust design. This paper analyzed the performance correlation equation through the frequency and sensitivity database according to a design factor change. The new concept is that the performance prediction is possible without repeated activities of test and analysis. This paper described the parameter analysis applications such as bush dynamic stiffness and bush void direction of rear suspension. Design engineer could efficiently decide the design variable using parameter analysis database in early design stage. These improvements can reduce man hour and test development period as well as to achieve stable NVH performance.

• Journal of the Optical Society of Korea
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• v.15 no.2
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• pp.182-186
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• 2011

A poling method using multiple negative voltage was introduced to fabricate periodically poled lithium niobate (PPLN) devices with quasi-phase matching (QPM) period of $12.9\;{\mu}m$ by utilizing an real-time visualization system. We also performed variation of the electric field during the poling. Two different conventionally used poling method, negative and positive single pulses, were used and the poling quality compared through microscopic images and far-field diffraction pattern analysis. Etched images on the +z and -z surfaces of PPLN showed that negative multiple pulse poling presented the highest periodicity in domain structures among the three methods. Duty ratio and its standard deviation were measured by analyzing far-field diffraction patterns. The newly introduced method of negative multiple pulse poling had duty ratio of 0.42 which was close to the ideal value of 0.50 and standard deviation of 0.020 that was about 3 times smaller than that of the other conventional methods.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.6
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• pp.1358-1365
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• 2014

This study is to analyze the variability of floating marine debris(FMD) on the Kuroshio Current Area(KCA). A sighting survey was conducted from July 5th to July 16th, 2013 while navigating on KCA from Keelung, Taiwan to Tokyo, Japan using T/V KAYA of Pukyong National University. The sampled zones were divided into 6 transects and observed FMD during daytime in each transect. And also specified with 56 segments by defined one hour tracking distance as one segment on the survey routes. The results are as follows: 1. Hourly deviation of FMD's quality in each transect goes up to 10 times at NT, HS and SK. The others 3 times or so. 2. During the surveys, the largest amounts of it were found as total mean of $31.0num(ea)/km^2$ at NT transect in the northern part of Taiwan. So it is estimated because this area has gotten out of KCA. 3. And also quality of it on KCA was not directly related to Kuroshio Current's strong or weak. In conclusion, For the more detailed results on KCA are required of much more surveys.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.11
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• pp.3050-3063
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• 2023

Recommendation systems provide personalized products or services to online users by mining their past preferences. Collaborative filtering is a popular recommendation technique because it is easy to implement. However, with the rapid growth of the number of users in recommendation systems, collaborative filtering suffers from serious scalability and sparsity problems. To address these problems, a novel collaborative filtering recommendation algorithm is proposed. The proposed algorithm partitions the users using affinity propagation clustering, and searches for k nearest neighbors in the partition where active user belongs, which can reduce the range of searching and improve real-time performance. When predicting the ratings of active user's unrated items, mean deviation method is used to impute values for neighbors' missing ratings, thus the sparsity can be decreased and the recommendation quality can be ensured. Experiments based on two different datasets show that the proposed algorithm is excellent both in terms of real-time performance and recommendation quality.

• Corrosion Science and Technology
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• v.23 no.3
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• pp.228-234
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• 2024

Zinc wiping is a phenomenon used to control zinc-coating thickness on steel substrate during hot dip galvanizing by equipment called air knife. Uniformity of zinc coating weight in length and width profile along with surface quality are most critical quality parameters of galvanized steel. Deviation from tolerance level of coating thickness causes issues like overcoating (excess consumption of costly zinc) or undercoating leading to rejections due to non-compliance of customer requirement. Main contributor of deviation from target coating weight is dynamic change in air knives equipment setup when thickness, width, and type of substrate changes. Additionally, cold coating measurement gauge measure coating weight after solidification but are installed down the line from air knife resulting in delayed feedback. This study presents a coating weight control model (Galvantage) predicting critical air knife parameters air pressure, knife distance from strip and line speed for coating control. A reverse engineering approach is adopted to design a predictive, prescriptive, and descriptive model recommending air knife setups that estimate air knife distance and expected coating weight in real time. Implementation of this model eliminates feedback lag experienced due to location of coating gauge and achieving setup without trial-error by operator.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.5
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• pp.773-787
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• 2020

In the injection molding process, the controlling stability of products quality is a very important factor in terms of productivity. Even when the optimum process conditions for the desired product quality are applied, uncontrollable external factors such as ambient temperature and humidity cause inevitable changes in the state of the melt resin, mold temperature. etc. Therefore, it is very difficult to maintain prodcut quality. In this study, a system that learns the correlation between process variables and product weight through artificial neural networks and predicts process conditions for the target weight was established. Then, when a disturbance occurs in the injection molding process and fluctuations in the weight of the product occur, the stability control of the product quality was performed by ANN predicting a new process condition for the change of weight. In order to artificially generate disturbance in the injection molding process, controllable factors were selected and changed among factors not learned in the ANN model. Initially, injection molding was performed with a polypropylene having a melt flow index of 10 g/10min, and then the resin was replaced with a polypropylene having a melt floiw index of 33 g/10min to apply disturbance. As a result, when the disturbance occurred, the deviation of the weight was -0.57 g, resulting in an error of -1.37%. Using the control method proposed in the study, through a total of 11 control processes, 41.57 g with an error of 0.00% in the range of 0.5% deviation of the target weight was measured, and the weight was stably maintained with 0.15±0.07% error afterwards.