• Journal of Biosystems Engineering
• /
• v.33 no.2
• /
• pp.130-135
• /
• 2008

The purpose of this study was to develop a preprocessor for real-time portable quality evaluation system of milk. The preprocessor consisted of two flow pump to supply milk sample and reaction reagent at given volume, a fan to mix milk with reaction reagent, a thermoelectric device to maintain sample temperatures of $40^{\circ}C$, and I/O interface to control signals. The tests conducted with different level of flow rate of pump, fan speed, ambient temperature, and intial temperature of mixtures. To evaluate performance of the preprocessor, the supplied volumes, color changes, and temperatures were measured and analyzed. The results showed that the preprocessor could control supplying volumes, mixing, temperatures of samples automatically. The preprocessor showed good performance to be used for portable quality evaluation system of milk.

• Journal of Applied Reliability
• /
• v.10 no.4
• /
• pp.279-297
• /
• 2010

AQS(Air Quality Control System) is the important part of a car air conditioning system. This device intercepts automatically the influx of harmful waste gas. In this paper reliability assessment criteria for AQS are established in terms of quality certification test and lifetime test. The former quality certification test comprises general performance test and environmental test. Items which pass the test undergo lifetime test which guarantees the extent of mean lifetime with certain confidence.

• Proceedings of the KIEE Conference
• /
• 2001.07b
• /
• pp.729-732
• /
• 2001

Digital signal processors(DSP) are widely used in modern power conversion devices, ac motor drives. However, generating pulse-width modulation(PWM) gating signals requires so high sampling rates that most computation resources of the DSP must be devoted to generating them. This paper presents an ASIC realization of 2 channel space-vector PWM(SVPWM). The developed DSP(ECLDSP) board can transmit gating signals to 2 converter/inverter and control them. ECLDSP board is used for control the various kinds of power-quality improvement systems.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.20 no.3
• /
• pp.209-213
• /
• 2015

With the increasing popularity of renewable generation systems and the advancement of power electronics, DC distribution systems have recently received considerable research attention. DC distribution has numerous advantages, including reliability, power quality, and efficiency. Owing to these advantages, DC distribution has been applied to data centers and power quality-sensitive electronic load conditions. Because grounding electrodes in DC are much more susceptible to corrosion than in AC, the IT system defined in IEC Standard 60364 may be a good candidate for an earthing method for DC distribution systems. In addition, IEC Standard 61557 specifies the requirements for insulation monitoring devices (IMD) for protection of the IT system, which continuously monitors the insulation resistances between the power lines and the earth. This paper discusses the development and evaluation of IMD to promote the reliability of distribution systems and increase safety of humans and facilities.

• Food Science of Animal Resources
• /
• v.36 no.1
• /
• pp.19-22
• /
• 2016

This study was conducted to improve sensory quality of Jokbal (Korean Pettitoes) made from frozen pig feet by addition of herbal mixture (glasswort, raspberry and Sansa powders). After adding herbal mixture, lipid oxidation (2-thiobarbituric acid values, TBARS), sensory property, and textural property were determined. Herbs were individually added into cooking soup at concentration of 6% (low concentration treatment, LCT) or 12% (high concentration treatment, HCT) of raw pig feet. Refrigerated pig feet were used as control. Thawed feet without any herbal mixture were used as freezing treatment (FT). TBARS in LCT or HCT were lower than that in FT, and showed the similar to that in Control. Addition of the herbal mixture was effective in improving the flavor and textural property of thawed feet by inhibiting lipid oxidation and protein denaturation in a dose-dependent manner.

• ETRI Journal
• /
• v.36 no.4
• /
• pp.617-624
• /
• 2014

Through-silicon via (TSV) technology provides much of the benefits seen in advanced packaging, such as three-dimensional integrated circuits and 3D packaging, with shorter interconnection paths for homo- and heterogeneous device integration. In TSV, a destructive cross-sectional analysis of an image from a scanning electron microscope is the most frequently used method for quality control purposes. We propose a quantitative evaluation method for TSV etch profiles whereby we consider sidewall angle, curvature profile, undercut, and scallop. A weighted sum of the four evaluated parameters, nominally total score (TS), is suggested for the numerical evaluation of an individual TSV profile. Uniformity, defined by the ratio of the standard deviation and average of the parameters that comprise TS, is suggested for the evaluation of wafer-to-wafer variation in volume manufacturing.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.08a
• /
• pp.423-428
• /
• 1999

A high precision hot strip width control method has been developed in this study by applying interstand looper tension measuring system at finishing mill stands. As with deviation of hot rolled steel strip is closely related to abnormal increase in the interstand strip tension, on-line measuring device of looped tension and data analyzing system was developed in this study. To determine dominant factors that will cause local width shortage, the logged data sets of bar width, bar thickness, looper tension, and strip thickness along the strip length were correlated with the data set of strip width change. With the result of the correlation analysis, existing sequence control logic and parameters for looper actuator were modified for strip width quality and the gains of the looper control were refined for the stable operation during the full passage of rolled strip. The on-line tension measurement and tension feedback control for looper system improved strip travelling stability and reduced strip width deviation in the srip top end region.

• 제어로봇시스템학회:학술대회논문집
• /
• 1990.10a
• /
• pp.79-84
• /
• 1990

Analog systems could not fully deal with instrumentation and control facilities in power plants since these facilities have become more and more complex on account of various needs for large power generation capacity highly cost effective operation to conserve energy and operation management to prevent pollution. Digitalizations of control device and augmentations of control informations increased the necessity of fiber optic data networks which have excellent noise immunity and high quality wide-band with information transfer capability. The goal of this study is to offer a fiber optic data-way system which has high reliabilities, high data transmission rates and small cable ducts with large transmission capacities for the instrumentation and control of power plants.

• Korean journal of applied entomology
• /
• v.61 no.4
• /
• pp.615-622
• /
• 2022

In this study, we sought to determine an appropriate LED light source that can be applied for the quality control of Aphidius colemani. Four LED light sources (385, 405, 450, and 660 nm) were evaluated in a Y-tube experiment (choice test) using a 5,000-k white LED as a control. The 385 nm LED light source was found to have attractant effect on A. colemani. In a no-choice test (Y-tube experiment) evaluating the remaining three LED light sources (385, 405, and 450 nm), the attractiveness of these light sources for A. colemani was high in the order 450 nm > 385 nm > 405 nm light, with no statistically significant differences between 450 nm and 385 nm. Given that 385 nm LED illumination may cause skin damage, we selected 450 nm LEDs for application in a device used for the quality control of A. colemani, which we subsequently demonstrated to have an attraction rate of 87.4%. We believe the findings of this study will make a valuable contribution to the quality control of natural enemies.

• International Journal of Control, Automation, and Systems
• /
• v.6 no.2
• /
• pp.186-193
• /
• 2008

The Internet's low cost and ubiquity present an attractive option for real-time distributed control of processes on the factory floor. When integrated with the Internet, the LonWorks open control network can give ubiquitous accessibility with the distributed control nature of information on the factory floor. One of the most important points in real-time distributed control of processes is timely response. There are many processes on the factory floor that require timely response. However, the uncertain time delay inherent in the network makes it difficult to guarantee timely response in many cases. Especially, the transmission characteristics of the LonWorks/IP network show a highly stochastic nature. Therefore, the time delay problem has to be resolved to achieve high performance and quality of the real-time distributed control of the process in the LonWorks/IP Virtual Device Network (VDN). It should be properly predicted and compensated. In this paper, a new distributed control scheme that can compensate for the effects of the time delay in the network is proposed. It is based on the PID controller augmented with the Smith predictor and disturbance observer. Designing methods for output feedback filter and disturbance observer are also proposed. Tracking position control experiment of a geared DC Servo motor is performed using the proposed control method. The performance of the proposed controller is compared with that of the Internal Model Controller (IMC) with the Smith predictor. The result shows that the performance is improved and guaranteed by augmenting a PID controller with both the Smith predictor and disturbance observer under the stochastic time delay in the LonWorks/IP VDN.