• Journal of KIISE:Computing Practices and Letters
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• v.16 no.2
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• pp.201-206
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• 2010

PLCs are special purpose microcontrollers used in most automatic control systems such as plants, embedded systems, and intelligent buildings. LD is one of the most popular languages among PLC languages. For now LD programs are mainly verified by simulation and testing which has a lot of limitation. This paper describes how to translate a given LD program into an input of a model checker so that LD program is verified by model checking. We define formal semantics of LD programs and SMV models and specify a formal definition of the translation function which preserves semantics between LD programs and SMV models.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5134-5139
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• 2013

Ladder Diagram(LD) or Sequential Function Chart(SFC) is used for the design of complex modern control system with Programmable logic controller(PLC). LD is the most widely utilized among PLC standard language. But recently, SFC is used frequently. SFC is very easy to grasp the sequential flow of control logic but is difficult for describing combinational logic. When the interrupt factor is occurred, the main program is stopped. And after the interrupt program is completed, the main program is restart. Therefore the more complex the interrupt program, the main program is interrupted downtime will be that much longer. In this paper, we propose the method for interrupt implementation without the dwell time of the main program by SFC language and confirm his feasibility through the simulation.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.3
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• pp.140-151
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• 1996

In this paper, we analyze the variations of thermal characteristics of LD (laser diode) arrays packaged by a flip-chip bonding method. When we simulate the temperature distribution in LD arrays with a BEM (boundary element method) program coded in this paper, we find that thermal crosstalks in LD arrays packaged by the flip-chip bonding method increases by 250-340% compared to that in LD arrays packaged by previous methods. In the LD array module packaged by the flip-chip bonding technique without TEC (thermo-electric cooler), the important parameter is the absolute temperature of the active layer increased due cooler), the important parameter is the absolute temperature of th eactiv elayers of LD arrays to thermal crosstalk. And we find that the temperature of the active layers of LD arrays increases up to 125$^{\circ}C$ whenall four LDs, without a carefully designed heatsink, are turned on, assuming the power consumption of 100mW from each LD. In order to reduce thermal crosstalk we propose a heatsink sturcture which can decrease the temeprature at the active layer by 40%.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.153-158
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• 2008

When we design the control system used Programmable Logic Controller(PLC), we program the main algorithm by Ladder Diagram(LD) in many standard language. But if we use an Sequential Function Chart(SFC), we is easy to know the sequential flow of control, to maintenance the controller and to describe a program. Even though a SFC have many merits, A SFC have some problems like a condition and a function of self test. Therefore this thesis show an efficient function of self test and we confirmed its feasibility through actual example.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1260-1268
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• 2005

Ladder Diagram(LD) is the most extensively used among PLC standard language for the design of control system. But LD has the disadvantages for data processing and maintenance. On the other hand, the Sequential Function Chart(SFC) graphic language is very powerful for describing the sequential logic control algorithm. SFC is based on flow chart, so control flow understanding is very easy and divergence can possible improving its ability. In this paper, we propose the efficient management elevator system using the action qualifiers and choice divergence. From the result, we confirm the SFC language reduced program memory capacity and processing time is faster than LD language.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.699-702
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• 1999

This paper represents the application of a virtual plant simulator and a Ladder Diagram of PLC. A target plant is a material transport car that repeatedly conveys along the rails. The whole process is automatically operated by PLC. The simulation system consists of the POSFA PLC and the virtual plant simulator. We demonstrate that operation of a LD program corresponds to operation of the virtual plant simulator.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.911-921
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• 2008

Learning disabilities (LD) are heterogeneous group of disorders with evidences of genetic or familial trait, intrinsic to the individual and presume to be due to central nervous dysfunction. Learning disabilities and attention deficit hyperactivity disorder (ADHD) are the two of the most common disorders in the population of school-age children. Typically academic achievements in children with learning disabilities are significantly lower than expected by their normal or above normal range of IQ. Although academic and cognitive deficits are hallmarks of children with LD, those children are also at risk for a broad range of behavioral and emotional problems. Almost all cases meet criteria for at least one additional diagnosis such as ADHD, developmental coordination disorder, depression, anxiety, obsessive compulsive disorder, tic disorder, among which ADHD is particularly predominant. Because of the response to the therapeutic intervention program is promising and positive when applied early, it is critical to recognize patients as early as possible. Pediatricians often are the first to hear from parents worried about a childs academic progress. It is not the responsibility of pediatrician to make a diagnosis, referring children for a diagnostic evaluation of LD is a reasonable first step. Pediatricians can make early referral of suspicious children by asking some serial short questions about basic and processing skills. With a basic knowledge about the clinical characteristics, diagnostic and therapeutic procedures of LD, pediatricians also can provide primary counseling and education for parents at their outpatient clinical settings.

• Journal of Internet Computing and Services
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• v.8 no.2
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• pp.67-76
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• 2007

Data used for the SFP module are stored in A0 and A2 memory area based on the SFP-MSA standard. In this paper the auto set-up program for SFP module has been designed and implemented. In order to make the Digital Diagnostic Monitoring Interface, the specific value has been written into the designated register via RS232 communication channel in the LD Driver IC. The Agilent VEE is used as a programming language for factory automation, and optical characteristics of SFP module and SFP-MSA standard are main structure of the implementation. The implemented program has been applied to the manufacturing field and the system gains a higher effect than the result of 6-Sigma.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.3 s.309
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• pp.60-66
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• 2006

The purpose of this study was to suggest a new detection method for early diagnosing diabetic neuropathic foot by obtaining a ratio of toe to finger blood flow using photoplethysmography(PPG) and Laser Doppler(LD). Nerve conduction velocity (NCV) has been routinely used for diagnosing neuropathic foot, but it applies strong electric stimulus to peripheries resulting in stress and pain. The blood flow ratio of 50 neuropathic diabetes($0.96{\pm}0.20$) was significantly higher than that of 64 normal person($0.46{\pm}0.15$)(p<0.000). It also showed that toe temperature of neuropathic diabetes($30.5{\pm}1.4^{\circ}C$) was significantly higher than that of normal group($29.3{\pm}2.0^{\circ}C$)(p<0.000). The optimal boundary value of the blood flow ratio was found to be 0.678 and the sensitivity and specificity of this proposed method resulted in 95.3% and 95.3% respectively. Lastly, there were no neuropathic diabetes whose temperature difference between finger and toe was higher than $4.5\;^{\circ}C$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.49-55
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• 2006

In industrial control system used by Programmable Logic Controller(PLC), ladder Diagram(LD) is the must widely utilized and plays an important role in industrial control system. But recently, the study about Sequential Function Chart(SFC) is performed actively. When we program by SFC, generally, we design one routine from start to end. This method is difficult to design, and we often make mistakes. In this paper, we propose the method that we compose each sub-system after we design each sub-system and confirm his feasibility through an actual examples.