• International Journal of Aerospace System Engineering
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• v.4 no.1
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• pp.13-21
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• 2017

In this paper, we present some results on performance analysis for flap actuation system of aircraft. For this, by utilizing MATLAB/Simulink solution, which is widely used physical model-based design tool, we particularly construct the architecture of the analysis model consisting of the main three phases: 1)commanding and outer-controlling the flap angle through flight control computer; 2)generating hydraulic/mechanical power through control module and power drive unit; 3)transmitting torque and actuating the flap through torque tube and rotary geared actuators. For mimicking the motion of the actual flap, we apply each mechanical component, which is already being used in actual aircraft, to our performance analysis model so that it guarantees the congruency of the simulation results. That is, we reflect the actual specifications of flap hardware and software as parameters of the model. Finally, simulation results are presented to illustrate the model.

• Human Ecology Research
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• v.55 no.3
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• pp.289-301
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• 2017

This study was to analyze the effects of the career education program for students with disabilities. The analysis was performed based on two research questions. First, the total effect size on the career program for students with disabilities was considered. Second, the difference of the effect size between the sub-groups regarding dependency variables, types of disabilities, types of schools, number of people, and number of sessions was also included for analysis. For this, the author reviewed a database and analyzed 12 previous studies, presented in five master thesis and seven Korean journals from 2005 to 2015 based on the author's selection criteria. Subsequently, 27 effect size was found. The publication bias was analyzed by Rosenthal's fail-safe N. The overall effect size for all studies on the random effect model was 1.717, which was positive and high in value. Given the heterogeneity among the effect size, the subgroup analysis was conducted, and indicated that the effect size was significantly high when the purpose of the program was related to the student's self-decision ability. The results demonstrated that the programs were specified for students with intellectual disabilities, when the schools were elementary, when the number of students in a group was 1-10, and when program sessions lasted more than 21 times, the effect size was high. Implication for the future research and program implication were discussed on these findings.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.33-38
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• 2012

EMB is considered as the next generation braking mechanism because it has simple structure and is environment friendly. However, as other brake mechanisms, EMB should be operated reliably for any operating conditions. EMB should be designed with fail-safe and fault-tolerant control concepts which require robust fault detection algorithms for various possible faults. In the design of fault detection algorithms, it is very difficult to construct faulty conditions in real EMB and thus, simulations are often used to emulate the faulty conditions. In this paper, a simulation tool is developed using the commercial software to emulate gear faults in the EMB mechanism. A backlash compensation algorithm is introduced based on contact point detection because screw backlash causes a delay in clamping force response time.

• Journal of Korean Institute of Industrial Engineers
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• v.2 no.1
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• pp.61-78
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• 1976

The purpose of this study is to establish the horizontal and vertical working area which is dependent on measuring value of workers, body in order to make easy and stable working environments, and then to design the size of machines, tools and instruments in production factory because of making the practical production conditions which is the most suitable to human characteristics. But there is necessity that we have to review numeric value of measurement periodically because the size of workers' body is variable according to periodic and social circumstances. The establishment of standard working area after measurement enable us to make the best working conditions and we can design standard working table, optimum size of all machines and tools in production activity. Therefore, we can also acknowledge the importance of studying on human engineering because human engineering is necessary to reduction of fatigue in working, saving workers from industrial accidents, fail-safe system, improvement of productivity with increase in efficiency and etc. Finally, this study informs us that numeric value of measurement is larger than that of Japan, but not than that of America and Germany. So we can establish standard working area which is the most suitable for Korean inherence after measurement of detailed parts for workers' body.

• Asian Oncology Nursing
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• v.12 no.4
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• pp.257-266
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• 2012

Purpose: The purpose of this study was to evaluate the effectiveness of patient education interventions on distress, self-care knowledge and self-care behavior in cancer patients. Methods: A total of 1,102 studies were retrieved from 6 electronic databases in Korea. From these studies, 18 studies met the inclusion criteria with a total of 850 participants. Two authors independently assessed the methodological quality by Cochrane's Risk of Bias and Methodological Items for Non Randomized Studies. The data were analyzed by the RevMan 5.1 program of Cochrane library. Results: Overall effect size of education interventions on anxiety was -2.12 (95% CI:-3.90, -0.34) (p<.001). The effects on self-care knowledge and self care behavior were -1.08 (95% CI:-1.73, -0.43) (p=.001), and -1.41 (95% CI:-2.13, -0.68) (p<.001), respectively. Publication bias was detected as evaluated by funnel plot, but the fail-safe number was moderate. Conclusion: This study suggests that patient education interventions can relieve anxiety and self-care. Further randomized controlled trials studies are needed to evaluate the effects of patient education intervention on depression.

• Korean Journal of Psychosomatic Medicine
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• v.22 no.2
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• pp.63-70
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• 2014

The prevalence of obesity and overweight is increasing in mood disorder, and it is connected to an increased cardiovascular mortality. Because of them, treatment for obesity may be an essential part of mood disorder treatment. Similar to the general population, non-pharmacological treatment such as correction of life habits should be considered first of all. If this approaches are fail, pharmacological treatment for obesity would be required as next step. Any drug for obesity is not approved officially in mood disorder. So approved drugs in general population, and drugs supported by several studies are prescribed in clinical settings. Several treatment guidelines for mood disorder and studies support that orlistat, metformin, topiramate and bupropion is effective and safe.

• Journal of information and communication convergence engineering
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• v.10 no.4
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• pp.405-410
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• 2012

Several attempts have been made to add journaling capability to a traditional file allocation table (FAT) file system. However, they encountered issues such as excessive system load or instability of the journaling data itself. If journaling data is saved as a file format, it can be corrupted by a user application. However, if journaling data is saved in a fixed area such as a reserved area, the storage can be physically corrupted because of excessive system load. To solve this problem, a new method that dynamically allocates journaling data is introduced. In this method, the journaling data is not saved as a file format. Using a reserved area and reserved FAT status entry of the FAT file system specification, the journaling data can be dynamically allocated and cannot be accessed by user applications. The experimental results show that this method is more stable and scalable than other log-based FAT file systems. HFAT was tested with more than 12,000 power failures and was stable.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.115-116
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• 2006

Since the discovery of the high-temperature superconductors, many researches have been performed for the practical applications of superconductivity technologies in various fields. As results, significant progress has been achieved. Especially, Superconducting Fault Current Limiter (SFCL) offers an attractive means to limit fault current in power systems. The SFCLS, in contrast to current limiting reactors or high impedance transformers, are capable of limiting short circuit currents without adding considerable voltage drop and energy loss to power systems during normal operation. Under fault conditions, a resistance is automatically inserted into the power grid to limit the peak short-circuit current by transition from the superconducting state to the normal state, the quench. The advantages, like fail safe operation and quick recovery, make SFCL very attractive, especially for rapidly growing power systems with higher short-circuit capacities. In order to verify the effectiveness of the SFCL, in this paper, the analysis of fault current and voltage stability assessment in a sample distribution system and a transmission system are performed by the PSCAD/EMTDC based simulation method. Through the simulation, the advantage of SFCL application is shown, and the effective parameters of the SFCL are also recommended for both distribution and transmission systems. A resistive type component of SFCL is adopted in the analysis. The simulation results demonstrate not only the effectiveness of the proposed simulation scheme but also SFCL parameter assessment technique.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.2
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• pp.203-210
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• 2015

This paper investigates the failure of a car with a 2.5-liter CRDi engine of the Hyundai Company. The failure is caused by intermittent poor acceleration while driving. To analyze the cause, we investigated the air intake volume, the fuel injection, and the air-fuel ratio, which were determined to be normal. The brake switch signal error was discovered while analyzing the function that limits the output of the engine. While investigating the cause, we discovered the corrosion of the pins on the connector of the brake switch. We determined that it was generated by soapy water flowing in the solar film. Therefore, the cause of the failure was the brake switch signal errors. Additionally, we determined that ECM was the normal fail-safe mode that implemented the override device for safety during normal acceleration. Based on these results, further solar film experiments must be conducted to fully elucidate the causes.

• Nuclear Engineering and Technology
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• v.32 no.4
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• pp.316-327
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• 2000

The Emergency Core Cooling System in current nuclear power plants typically has a considerable number of complex functions and largely cumbersome operator interfaces. Functions for initiation, switch-over between various phases of operation, interlocks, monitoring, and alarming are usually performed by relays and analog comparator logic which are difficult to maintain and test. To improve problems of an analog based ECC (Emergency Core Cooling) System, the trip computer for ECCS based on Dynamic Safety System (DSS) is implemented. The DSS is a computer based reactor protection system that has fail-safe nature and performs a dynamic self-testing. The most important feature of the DSS is the introduction of test signal that send the system into a tripped state. The test signals are interleaved with the plant signals to produce an output which switches between a tripped and health state. The dynamic operation is a key feature of the failsafe design of the system. In this work, a possible implementation of the DSS using PLC is presented for a CANDU Reactor. ECC System of the CANDU Reactor is selected as the reference system.