• Korean Journal of Community Nutrition
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• v.15 no.1
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• pp.94-107
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• 2010

The purpose of this study was to examine the interrelations among current status of nutrition education, satisfaction with school lunch, school lunch leftovers and self-rated mental or physical health in order to find out the effective method of nutrition education. For this, a questionnaire survey of 623 primary school 5th and 6th-graders in Daejeon area was carried out. The eating places were classrooms (41.1%) and restaurants (58.9%). A 59.2% of students have received nutrition education and the opportunity of receiving nutrition education was more in 5th-graders than in 6thgraders (p < 0.001). The score of nutrition knowledge was $9.4\;{\pm}\;2.8$ out of 15. When the score of nutrition knowledge was higher, the practical use of nutrition knowledge was higher (r = 0.134, p < 0.01); the score of school lunch leftovers were less (r = -0.116, p < 0.01); and the score of self-rated mental health was more positive (r = 0.198, p < 0.01). The practical use of nutrition knowledge was $2.9\;{\pm}\;1.1$ out of 5. When the practical use of nutrition knowledge was higher, satisfaction with school lunch was higher (r = 0.105, p < 0.01); school lunch leftovers were less (r = -0.103, p < 0.01); the score of self-rated positive mental health was higher (r = 0.293, p < 0.01); and the scores of self-rated negative mental health (r = -0.119, p < 0.05) and physical health (r = -0.126, p < 0.01) were lower, thus rating their health more positively. The score of satisfaction with school lunch was $3.4\;{\pm}\;1.0$ out of 5. When the satisfaction with school lunch was higher, the score of school lunch leftovers was less (r = -0.216, p < 0.01); the score of self-rated positive mental health was higher (r = 0.147, p < 0.01); and the score of self-rated negative health was lower (r = -0.121, p < 0.01). The score of school lunch leftovers was $2.9\;{\pm}\;1.4$ out of 5. When the school lunch leftovers were less, self-rated positive mental health was significantly higher (r = -0.146, p < 0.01); and the scores of self-rated negative mental health (r = 0.135, p < 0.01) and physical health (r = 0.223, p < 0.01) were significantly lower, thus presenting positive health. Therefore, in order to maintain positive health condition, it is necessary to carry out nutrition education, which is able to raise the nutrition knowledge and practical use of nutrition knowledge, school lunch satisfaction and to reduce the school lunch leftovers.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.735-736
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• 2008

There are many equipments for the Short Circuit Test, for example Short Circuit Generator, Induction Motor, Sequence Timer, CLR, Back Up Breaker, Making Switch and Excitation Equipment etc. Gradually an allowable tolerance of the short circuit test voltage is become smaller by the standards for short circuit test. The excitation equipment of short circuit generator is very important for test voltage is adjusted by the excitation equipment. Especially the excitation equipment must be possessed character of exactitude, durability and inalterability because some times around 10,000 times opening and closing short circuit test is requested by clint, which must be done within one minute. The purpose of this study for function and operation of the excitation equipment which rated DC voltage is 1,000V, rated DC current is 300A, rated out put is 30kW and type is YNEX 97S-441/609, is to help operation of short circuit generator.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.549-553
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• 2015

For successful outcome of real estate development projects, it is important to understand the potential tenants as they drive the demand for properties. The aim of this study is to investigate tenant characteristics of the Australian green office building sector. The specific objectives are to; (1) compare and contrast the increment trend of green buildings within the green office building sector; (2) identify the tenancy profile of green buildings; (3) ascertain the possible industry concentrations within the current green building sector; and (4) explore the relationship between green building occupants' characteristics and their tenancy. Descriptive statistics shows that Finance, Insurance and Real Estate (FIRE) industries along with government owned companies are the major tenants of green office buildings in the NSW State of Australia. In particular, real estate companies occupy more than half of the NSW based green office buildings whilst one third of them are the tenants of the 6-star rated buildings - the highest rated building in the current form of Australian Green Star accreditation scheme.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.1
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• pp.91-98
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• 1999

An integrated ZCS quasi-resonant converter(QRC) for the power factor correction with a single switch is presented in this paper. The power factor correction can be achieved by the discontinuous conduction mode(DCM) operation of the input current. The proposed converter gives the good power factor, low line current harmonics, and tight output regulation. The input current waveform of the prototype designed using design equations shows about 15% of total harmonic distortion at rated condition. Also, the efficiency and power factor can be obtained about 86% and 0.985, respectively, at rated condition. The proposed converter is suitable for a low power level converter with a tightly regulated low output voltage and switching frequency of more than several hundreds kHz.

• Journal of Power Electronics
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• v.15 no.1
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• pp.116-122
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• 2015

This paper presents a new current sharing control strategy for parallel-connected, synchronised three-phase DC-AC converters employing space vector pulse width modulation (SVPWM) without current sharing reactors. Unlike conventional control methods, the proposed method breaks the paths of the circulating current by dividing the switching cycle evenly between parallel connected equally rated converters. Accordingly, any inter-module reactors or circulating current control will be redundant, leading to reductions in system costs, size, and control algorithm complexity. Each converter in the new scheme employs a synchronous dq current regulator that uses only local information to attain a desired converter current. A stability analysis of the current controller is included together with a simulation of the converter and load current waveforms. Experimental results from a 2.5kVA test rig are included to verify the proposed control method.

• Fire Science and Engineering
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• v.34 no.2
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• pp.64-71
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• 2020

In this paper, the fire risk of a single-phase induction motor under a locked-rotor condition is described. In general, motor failure occurs in the locked-rotor condition owing to poor rotation of the rotor. Large inrush current flows when a motor starts, which is approximately 2-15 times larger than the rated current. In a single-phase induction motor under the locked-rotor condition, a large current that corresponds to the inrush current flows continuously through the stator winding. Such an overcurrent rises the temperature inside the stator winding, and thus the insulating material may catch fire. In this study, the restrained operating condition of the single-phase induction motor was simulated. Further, the degree of the overcurrent and temperature rise in the stator winding was measured. The experimental results, confirmed that the overcurrent was seven times larger than the rated current and the fire commenced at a temperature of approximately 300 ℃ inside the stator winding.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.492-494
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• 2006

Neutral line current is analyzed by the neutral line CF in nonlinear load balanced and unbalanced conditions. The worst nonlinear load condition is nonlinear balanced load condition, and It is below CFNL=1.194 that a neutral line current could not excess the rated value

• Journal of Power Electronics
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• v.9 no.1
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• pp.68-73
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• 2009

Automotive inverters may require current sensors for motor torque control, especially, in applications of hybrid electric vehicles or fuel cell vehicles. In this paper, to achieve a compact, integrated and low cost current sensor, a hall current sensor without magnetic core is introduced for integrating an automotive inverter. The compactness of the current sensor is possible by using integrated magnetic concentrators based on the Hall effect. Magnetic fields caused by three-phase currents are analyzed and a magnetic shield design is proposed for decoupling the cross-coupled field. It offers galvanic isolation, wide bandwidth (>100kHz), and accuracy(< 1%). Using 2D FEM analysis, its performance is demonstrated with design parameters at a U-shaped magnetic shield. The proposed coreless current sensor is tested with rated current to validate the linearity and accuracy.

• Progress in Superconductivity and Cryogenics
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• v.10 no.2
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• pp.34-37
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• 2008

According to the recent design of an HTS (High Temperature Superconducting) power transformer whose capacity is hundreds MVA, the rated current values of the low voltage side are generally over thousands amps. Considering the performance of the recent HTS wires, it is inevitable to use several HTS wires in parallel for large rated current. Lots of stacked HTS wires were fabricated and tested so far, and the results have showed that we have to transpose each wire in order to reduce the AC losses as well as to increase the current capacity. But many development programs about HTS transformers reveal that the transposition of the several wires during the winding process is quite difficult not only in case of the layer windings but also in case of the pancake type ones. So, we need transposed multiple HTS wire which we can handle like single wire or cable for the HTS windings of large capacity power transformer. We fabricated several kinds of samples of multiple HTS wire with transposition to apply it to the HTS windings of power transformer. The electrical characteristics such as critical currents or AC losses are analyzed by experiments in case by case. Finally we present the best design of a multiple HTS wire for power transformer.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.193-196
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• 1999

The current boost type atatic excitation system for synchronous generator that can sustain prope output voltage level even at fault condition is proposed. The proposed excitation system is capabl of supplying level 60% of the rated voltage. The proposed system is verified and tested using computer simulations as well as load tests. The load tests are performed with a 5KVA synchronous generator driven by a ac motor. The actual tests results indicated a good performance.