• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.10
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• pp.59-68
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• 2009

The field oriented control of induction motors is widely used in high performance applications. However, detuning caused by parameter disturbance still limits the performance of these drives. In order to accomplish variable speed operation, conventional PI-like controllers are commonly used. These controllers provide limited good performance over a wide range of operation, even under ideal field oriented conditions. This paper is proposed high performance control of induction motor drive using multi adaptive fuzzy controller. This controller has been performed for speed control with fuzzy adaptation mechanism (FAM)-PI, current control with model reference adaptive fuzzy control(MFC) and estimation of speed using ANN. The proposed control algorithm is applied to induction motor drive system using FAM-PI, MFC and ANN controller. The performance of proposed controller is evaluated by analysis for various operating conditions using parameters of induction motor drive. Also, this paper is proposed the analysis results to verify the effectiveness of this controller.

• Ocean and Polar Research
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• v.30 no.3
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• pp.351-359
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• 2008

In an effort to develop high-resolution sea surface temperature (SST) proxies for mid-latitude regions, two massive reef-building coral species, Alveopora and Favia, were collected from Jeju and Tsushima Islands, respectively. Their skeletons were subsequently analyzed for annual growth banding, Sr/Ca and Mg/Ca ratios. Hermatypic corals are thinly distributed in the waters of Jeju Island, where Alveopora japonica was the only dominant coral species. A higher diversity of hermatypic corals were observed in the waters of Tsushima Island, where Favia sp. was the most common coral species and even forming an about 6-m-high reef structure. Both Alveopora and Favia showed annual growth layers consisting of couplets of high- and low-density bands. Sr/Ca ratio of both species and Mg/Ca ratio of Alveopora also showed seasonal variation, likely reflecting SST variation. These results suggest the possibility that Alveopora and Favia species can be used as potential SST proxies. However, this study also highlights the potential growth disturbance of middle latitude corals due to high rainfall during monsoon and low SST during winter. This possibility should be taken into account in the investigation of Sr/Ca(Mg/Ca)-SST relationships.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.433-439
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• 2015

Recently, Interest in power the quality was increased because of increasing the use of sensitive load equipment into an electrical disturbance such as computer, Electricity, Electronics, Telecommunications and semiconductor device. In addition, To enhance power quality, the instantaneous voltage drop occurred in precision load equipment is a need for proper compensation. In order to solve the problem, The developed dynamic voltage restorer (DVR) using an electric double layer capacitor (EDLC) has been applied. In this paper, We will do study to apply hybrid capacitors that have high energy density to the same size compared to the EDLC to DVR. Also, As a emergency luminaires of emergency power supply that we can support more than 10 years of life was confirmed the applicability of hybrid capacitor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.4
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• pp.33-42
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• 2010

The induction motor drive applied to field oriented control is widely used in industry applications. However, it is deceased performance and authenticity by saturation, temperature changing, disturbance and parameters changing because modeling of induction motor is nonlinear and complex. In order to control variable speed operation, conventional PI-like controllers are commonly used. These controllers provide limited good performance over a wide range of operation, even under ideal field oriented conditions. This paper proposes self tuning PI controller based on fuzzy-neural network(FNN)-PI controller that is implemented using fuzzy control, neural network, and adaptive fuzzy controller(AFC). Also, this paper proposes estimation of speed using ANN. The proposed control algorithm is applied to induction motor drive system using FNN-PI, AFC and ANN controller. Also, this paper proposes the anlysis results to verify the effectiveness of controller.

• Journal of Astronomy and Space Sciences
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• v.20 no.3
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• pp.205-216
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• 2003

The attitude motion of a spin-stabilized, upper-stage spacecraft is investigated based on a two-body model, consisting of a symmetric body, representing the spacecraft, and a spherical pendulum, representing the liquid slag pool entrapped in the aft section of the rocket motor. Exact time-varying nonlinear equations are derived and used to eliminate the drawbacks of conventional linear models. To study the stability of the spacecraft's attitude motion, both the spacecraft and pendulum are assumed to be in states of steady spin about the symmetry axis of the spacecraft and the coupled time-varying nonlinear equation of the pendulum is simplified. A quasi-stationary solution to that equation and approximate resonance conditions are determined in terms of the system parameters. The analysis shows that the pendulum is subject to a combination of parametric and external-type excitation by the main body and that energy from the excited pendulum is fed into the main body to develop the coning instability. In this paper, numerical examples are presented to explain the mechanism of the coning angle growth and how angular momenta and disturbance moments are generated.

• Tunnel and Underground Space
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• v.28 no.4
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• pp.293-303
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• 2018

Monitoring is the act of collecting and analyzing accurate engineering information using various methods and instruments. The purposes of the monitoring are design verification, construction management, quality control, safety management, and diagnose of structure etc.. The diagnose evaluation of the geotechnical structures corresponds to the confirmation of the structural performance. It is aimed to judge the soundness of geotechnical structures considering the degree of damage due to the environmental change and elapsed time. Recently, microseismicity, which is widely known in Korea, can be used for safety management and diagnoses of structure as it detects the micro-damage without disturbance of the structure. This report provides guideline on the procedure for assessing an underground oil storage cavern using microseismic monitoring techniques. Guidelines cover the selection of monitoring systems, sensor array, sensor installation and operation of systems, and interpretation.

• Journal of Korean Society of Rural Planning
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• v.21 no.3
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• pp.145-154
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• 2015

With the rapid change of rural communities and increasing desire for social welfare, the demand for the quality of public spaces and facilities is increasing. However, inefficient location of rural public space and facility has caused problems such as economic inefficiency, inconvenient accessibility, environmental pollution, unsustainable energy use, and disturbance of visual landscape. This study aims to evaluate suitability of public spaces and facilities in three types of rural village: rural downtown village, rural clustered village, and individual village. As a way to measure the suitability of public spaces and facilities, we assessed indicators of suitability in terms of accessibility, usability, biophysical environment, and sustainable management. To evaluate the accessibility, we applied indicators such as distance from residential areas, public transit, market and public facilities. For the evaluation of biophysical environment, we applied indicators such as slope, elevation, aspect, and occurrence of natural disasters. We analyzed digital maps representing the indicators listed above using GIS. We also conducted a survey and face-to-face interviews to evaluate usability and sustainability of management which are not possible to understand through maps. As a result, we identified that suitability of public spaces and facilities in downtown villages is higher than clustered and individual villages. In particular, suitability of infrastructure facilities, social welfare facilities, and income generation facilities in downtown village are higher than those in clustered and individual villages. The suitability of tourism facilities is generally lower than other types of public facility across the three types of villages. Tourism facilities in clustered village have been identified especially unsuitable compared to other types of villages. We expect the outcome of the research is helpful to improve allocation of public spaces and facilities in rural villages.

• Journal of Acupuncture Research
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• v.25 no.1
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• pp.233-245
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• 2008

Multiple Myeloma is malignant tumor that malignant proliferous plasma cell to originate from bone marrow invades bone multiply. Objectives : Therapy for Multiple Myeloma includes chemotherapy, radiation therapy and self-stem cell transplantation, but it has no effect for a majority of Multiple Myeloma patients. So we diagnosed it as Wei symptom, oliguria, or dysuria(遺尿) in Oriental medicine, and treated it using the Oriental medical system. Methods : The patient was treated using acupuncture, electroacupuncture, herbal acupuncture treatment, moxibustion, physical treatment and western medicine. We observed 12 kinds of symptoms in the patient when admitted to the hospital. Results : 1. Paraplegia, urination desire, voluntary urination, and other symptoms improved except for a period of complication. 2. Defecation desire, sensory disturbance of the body and lower extremities, self-made changes, maintenance of body posture, and other symptoms improved during admitting days. 3. Voluntary defecation, pains of the neck and lower extremities, and other symptoms had irregular changes during admitting days. Conclusions : This study demonstrates the necessity of having more clinical study about Mutiple Myeloma.

• Korean Journal of Occupational Health Nursing
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• v.26 no.3
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• pp.184-196
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• 2017

Purpose: We investigated the effects of emotional labor and workplace violence on various physical and mental health outcomes among female workers. Methods: We obtained data from 24,760 female workers who participated in the 4th Korean Working Conditions Survey (2014). Hierarchical logistic regression analysis was used to analyze the relationships. Results: Female emotional workers were more exposed to workplace violence than were female non-emotional workers. Verbal abuse was the most common type of workplace violence. Logistic regression analyses revealed that (1) emotional labor was significantly associated with higher odds of having musculoskeletal or abdominal pain (physical health outcomes), along with overall fatigue (a mental health outcome), and (2) workplace violence experiences were significantly associated with higher odds of musculoskeletal pain, headache/eye strain, abdominal pain, depression/anxiety disorder, overall fatigue, and insomnia/sleep disturbance, after controlling for covariates. Conclusion: This study demonstrated that both emotional labor and workplace violence have negative effects on physical and mental health. However, workplace violence experience has a stronger negative impact on health outcomes than does emotional labor alone. A management system to eradicate workplace violence and programs aimed at managing emotional labor are urgently needed at the organizational level.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.4
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• pp.441-447
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• 2012

This paper presents a design technique of a Takagi-Sugeno (T-S) fuzzy-model-based $H_{\infty}$ controller for autonomous underwater vehicles (AUVs). The design procedure aims to render the stabilizing controller which satisfies performance of the diving control for AUVs in the presence of the disturbance. A nonlinear AUV is modeled by the T-S fuzzy system through the sector nonlinearity. By using Lyapunov function, the sufficient conditions are derived to guarantee the performance of robust depth control in the format of linear matrix inequality (LMI). To succeed for diving control of AUV, we add the constraints on the diving and pitch angles in the LMI conditions. Through the simulation, we confirm the effectiveness of the proposed methodology.