• Journal of Power Electronics
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• v.11 no.2
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• pp.148-155
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• 2011

Direct torque control(DTC) of induction machines is known to offer fast instantaneous torque and flux control with a simple control structure. However, this scheme has two major disadvantageous, namely, a variable inverter switching frequency and a high torque ripple. These problems occur due to the use of hysteresis comparators in conventional DTC schemes, particularly in controlling the output torque. This paper reviews the utilization of constant frequency torque controllers (CFTC) in DTC to solve these problems while retaining the simple control structure of DTC. Some extensions of the work in utilizing a CFTC will be carried out in this paper which can further reduce the torque ripple. This is particularly useful for a system which has a limited/low sampling frequency. The feasibility of a CFTC with an extended carrier frequency in minimizing the torque ripple is verified through experimental results.

• Journal of the Korean Society of Fashion and Beauty
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• v.4 no.1 s.7
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• pp.19-27
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• 2006

This study aims to analyze e potential and practical influences of physiognomic correction makeup that may change personal impression on faces, especially general physiognomy including eyebrow, cheek bones, lips. To meet this goal, this study looked into various literature materials on the basic concept and principles of physiognomy. With a series of photos showing 3 steps of makeup, i.e. a face before makeup, a face after general self-makeup and a face after makeup modified in physiognomic manner, a questionnaire survey was applied to the subjects. The results of survey can be outlined as follows It was found that physiognomic correction makeup could change various disadvantageous impressions into positive direction, impression of persons with thin eye brow looking like those with neither brightness nor deserving of any help from others, impression of persons with high cheek bones looking like the strong and masculine, impression of persons with small lips looking like the narrow-minded. Furthermore, physiognomic makeup changed positively changing the impression of persons with round chin looking like the ordinary than before.

• Ocean and Polar Research
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• v.24 no.4
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• pp.501-524
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• 2002

Article 121 of the UNCLOS stipulates the regime of islands and grants different jurisdictions to islands and rocks. Especially, paragraph 3 gives different definitions and distinguishes the legal status of between islands and rocks. That is, rocks, which cannot sustain human habitation or economic life cannot have their own EEZ, continental shelf or the great-sphere maritime jurisdiction. In this paper various theories and state practicess on islands and rocks are examined with reference to Article 121 of UNCLOS. Also, the status of Dokdo as a rock or an island is examined in accordance with the interpretation of Article 121 of UNCLOS. National legislations, practices, and many scientific opinions are often contradictory and controversial with respect to the interpretation of Article 121 of the UNCLOS. However, it is believed that Article 121 of UNCLOS, particularly paragraph 3 has to be interpreted more strictly. That is because the highly developed modem scientific technology can be meaningless when the criteria of Article 121 of UNCLOS are to be inappropriately applied. Insular figures like ${\ulcorner}rocks{\lrcorner}$ could bring the inequitable effects disadvantageous toward the other party when the maritime delimitation is applied. Claiming and Intentionally extending maritime zone of a coastal states by assigning EEZ for small insular figures like ${\ulcorner}rocks{\lrcorner}$ is over-zealous nationalism which is illegal, and such practices must be recognized as actions bringing great harm to the neighboring nations and demise of the sprit of all mankind.

• Journal of Applied Reliability
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• v.18 no.3
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• pp.213-219
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• 2018

Purpose: Satisfying the environmental regulations, the automobile manufacturer should install urea tank, which is a key component of the urea system. However, due to the limitations of existing layouts, it may be mounted which is disadvantageous to vibration and shock resulting in durability robust. analyze the factors affecting the durability life of urea tank and the vibration characteristics through RLDA. In this study, clarify the limit of the current practice test method of urea tank and analyze the possibility of the new vibration test method in the system unit reflecting the characteristics of actual use condition. Methods: Analyzing the factors affecting the durability life of urea tank and the vibration characteristics through PSD & FDS of RLDA that actual vehicle driving data on durability test road. Results: The limit of the uniform width/single frequency test method of urea tank is clarifed and the positive prospects of the new test method are discovered. Conclusion: The vibration durability test with PSD method in system unit effectively reflects the magnitude and frequency characteristics of field vibration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.4
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• pp.195-203
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• 2012

Dental implants using titanium have greatly advanced through the improvement of designs and surface treatments. Nonetheless, the anatomical limits and physiological changes of the patient are still regarded as obstacles in increasing the success rate of implants further, even with the enhancement of implant products. So there have been many efforts to overcome these limits. The intrinsic potential for bone regeneration can be stimulated through adjuvant treatments with the continuous improvement of implant properties, and this can play an important role in achieving optimum osseointegration toward peripheral bone tissue and securing ultimate long-term implant stability in standard surgical procedures. For this purpose, various chemical, biological, or biophysical measures were developed such as bone grafts, materials, pharmacological agents, growth factors, and bone formation proteins. The biophysical stimulation of bone union includes non-invasive and safe methods. In the beginning, it was developed as a method to enhance the healing of fractures, but later evolved into Pulsed Electromagnetic Field, Low-Intensity Pulsed Ultrasound, and Low-Level Laser Therapy. Their beneficial effects were confirmed in many studies. This study sought to examine bone-implant union and its latest trend as well as the biophysical stimulation method to enhance the union. In particular, this study suggested the enhancement of the function of cells and tissues under a disadvantageous bone metabolism environment through such adjunctive stimulation. This study is expected to serve as a treatment guideline for implant-bone union under unfavorable circumstances caused by systemic diseases hampering bone metabolism or the host environment.

• Journal of the Korean housing association
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• v.17 no.3
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• pp.111-121
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• 2006

The objective of the study is to derive the quantitative result and method from the solar simulation on the traditional architectonic control methods and their effects for the sunshine on Ddeuljip in Northern Area of Kyongsang-Bukdo Province, Korea. The Ddeuljip(rectangular-shaped housing plan having an inner court) has distinctive form to introduce plentiful sunshine deep inside to the house in spite of disadvantageous condition resulted from the structure of traditional housing composition, that is, Ickrang(linkage block connecting buildings). From the research on the Ddeuljip, following results were derived: First, in the plan the sunshine environment was improved by placing the master bedroom on the right diagonally, or projecting it toward the Ickrang when there isn't enough space for the inner court and the Daechung(wooden floored main hall). Second in the elevation specific sunshine control methods were developed by increasing the height of the master bedroom, reducing the eaves of south elevation, or differentiating the height of ceiling structure gradually.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1049-1053
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• 1999

It is important to measuring and monitoring about state vectors of power system for precise operation control. All state vectors cannot be measured because it is economically disadvantageous, so that some state vectors are determined using state estimator. Determination of observability is a important precondition of power system state estimation because state estimation can be performed when given power system is observable. Recently as time-synchronization technique progress, using the PMU(Phasor Measurement Unit), state vector can be measured directly so that voltage phasor and current phasor measurements can be used for power system estimation. In this paper, observability algorithm is proposed to determinate the observability with real/reactive injection power measurements and real/reactive lineflow power measurements of existing measurement system and with phasor measurements of PMU. The jacobian matrix is newly composed for state estimation with measurements of added PMU, and state estimation is performed with least square estimatior. Comparison between state estimation result of existing measurement system and that of measurement system added PMU is presented.

• Journal of Arbitration Studies
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• v.19 no.2
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• pp.73-94
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• 2009

There are significant differences between disputes among enterprises and disputes between consumers and an enterprise. A majority of consumers may suffer from the same damages at the same time with small amount concerned and sometimes low chances for find the real cause. Among these distinctive features, the most significant characteristic in consumer-business disputes can be found in that consumers are in a disadvantageous position compared to businesses. When it comes to consumer policy, the biggest aim lies with turning back the damage a consumer is suffering into normalcy. In this regard, the Consumer Dispute Resolution System is the most essential among consumer policies. In Korea, the Collective Alternative Dispute Resolution (ADR) System was introduced to the Consumer Dispute Resolution System in 2007 in line with revision on the Consumer Basic Law. However, smooth damage redress for consumers is still not taking place. Against this backdrop, this report suggests that 'consumer arbitration' program should be introduced to the Consumer Dispute Resolution System as part of making good and smooth progress for consumer damage redress.

• Journal of Power Electronics
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• v.18 no.3
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• pp.944-953
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• 2018

This paper proposes an analysis method based on the magnitude-phase dynamic theory for isolated power systems with static synchronous compensators (STATCOMs). The stability margin of an isolated power system is greatly reduced when a load is connected, due to the disadvantageous features of the self-excited induction generators (SEIGs). To analyze the control process for system stability and to grasp the dynamic characteristics in different timescales, the relationships between the active/reactive components and the phase/magnitude of the STATCOM output voltage are derived in the natural reference frame based on the magnitude/phase dynamic theory. Then STATCOM equivalent mechanical models in both the voltage time scale and the current time scale are built. The proportional coefficients and the integral coefficients of the control process are converted into damping coefficients, inertia coefficients and stiffness coefficients so that analyzing its controls, dynamic response characteristics as well as impacts on the system operations are easier. The effectiveness of the proposed analysis method is verified by simulation and experimental results.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.6
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• pp.290-295
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• 2002

The present assignment in installing the number of switches for distribution line was made on the basis of a normal feeder capacity 7,000kVA in KEPCO(Korea Electric Power Corporation), Korea. But the normal capacity is revised to 10000kVA in 1998. Even increasing limit of the operating capacity of the distribution lines enables us to give some benefit for the operation flexibility and investment cost of the distribution system. It is disadvantageous in the viewpoint of supply reliability. In distribution systems, switches are equipped to improve the reliability of distribution systems by minimizing the outage section due to fault and maintenance. Utility generally improves the reliability by minimizing the length of outage section, which is caused by fault and maintenance, through switch equipment on distribution system. In order to cope with the changes such as operation capacity, it is necessary to study whether the present criteria is reasonable or not, also to confirm whether the present criteria of installing switches in line is improved or not. In this study, we proposes the number of switch per feeder on the basis of present operation capacity in distribution system.