• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.469-470
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• 2007

There are many power system simulation software tools for time-domain performance in power system. This paper reports the results of time-domain simulation for the Jeju Power system with a secondary voltage regulation (SVR) model, developed with both TSAT and PSCAD/EMTDC and evaluates them, which are commercial software tools used for digital simulation of power system. TSAT has not been yet verified because of deficient modelling of components in the time domain performance of KEPCO power system. But PSCAD/EMTDC has been enough verified in our system. So, we need to compare and evaluate TSAT with PSCAD/EMTDC in small power system like Jeju. This paper showed that the results simulated by both TSAT and PSCAD/EMTDC is very similar to each other, so TSAT is able to apply for our KEPCO large power system.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.34-37
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• 2003

The frequency of power system will change when the load-generation equilibrium is disturbed. Insufficiency of generation from the imbalance between load and generation decreases the power system frequency. In case of the severe emergency, the under frequency load shedding scheme is applied for the power system defense plan. In this paper, we analyzed the dynamic characteristics of under frequency load shedding using new Transient Security Assessment Tool ; TSAT. We applied the actual UFLS scheme to these studies and considered the possible contingency.

• Childhood Kidney Diseases
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• v.13 no.2
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• pp.197-206
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• 2009

Purpose : Limited information is available on experiences of intravenous iron treatment in children. In this study, iron sucrose was administered intravenously to determine its effect, the factors predicting outcome, and safety in children on chronic dialysis. Methods : Twenty-one children whose serum ferritin levels were less than 100 ng/mL or transferrin saturations (TSAT) were less than 20% were enrolled. In 12 children on peritoneal dialysis (PD), the drug was infused intravenously as 200 mg/$m^2$ ($\leq$200 mg) at week 0, 2, 4, and 6. In 9 children on hemodialysis (HD), it was given intravenously as 8 weekly doses of 3 mg/kg ($\leq$100 mg) through week 0-7. Results : After treatment, serum ferritin levels increased significantly in both groups, and TSAT rose significantly in PD group. However, hemoglobin level did not rise significantly in both groups. Children with baseline hemoglobin less than 10 g/dL or baseline TSAT less than 20% showed significantly higher rise of hemoglobin after intravenous iron treatment. To the contrary, those with higher baseline hemoglobin and TSAT levels displayed higher rise in serum ferritin after the treatment. Although no serious adverse event occurred, TSAT levels exceeding 50% were noted in 6 patients in PD group. Conclusion : This suggests that 3 mg/kg/week of intravenous iron sucrose can be used safely in children on chronic HD, but 200 mg/$m^2$ every other week may incur excessive TSAT level in some patients on chronic PD.

• Food Science and Preservation
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• v.23 no.3
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• pp.335-340
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• 2016

This study was carried out to investigate the physicochemical and quality characteristics of acorn and acorn tea by processing methods. The moisture contents of acorn tea processed roasting was lower than those of others, and acorn tea processed by three steaming and drying was highest in among. Carbohydrate and crude lipid, crude ash contents of the acorn tea processed by roasting was higher than those of others. Crude protein contents of the natural acorn was higher than those of others. Soluble protein content of acorn tea produced by three steaming and drying was 12.74 mg/g, where was highest than that of the acorn tea. Reducing sugar content of natural acorn was 64.3 mg/g, higher than that of the acorn tea. The L values of natural acorn was higher than those of others, but steaming and roasting acorn tea were lower than those of others. The a, and b values of natural acorn was higher than those of others. Total polyphenol and flavonoid contents of acorn tea processed by three steaming and drying was 41.15, 2.78 mg/g, where was higher than that of the acorn tea. Sensory test was the acorn tea produced by three steaming and drying showed the best score in preference.

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.226-238
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• 2001

Background: Anemia in chronic renal failure plays an important role in increasing morbidity of dialysis patients. The causes of the anemia are multifactorial. With using of erythropoietin(EPO) most of uremia-induced anemia can be overcome. However, about 10% of renal failure patients shows EPO-resistant anemia. Hyporesponsiveness to EPO has been related to many factors: iron deficiency, aluminum intoxication, inflammations, malignancies and secondary hyperparathyroidism. So I evaluated the improvement of EPO responsiveness after correction of above several factors. Materials and Methods: Seventy-two patients on hemodialysis over 6 months were treated with intravenous ascorbic acid(IVAA, 300 mg t.i.w. for 12 weeks), After administration of IVAA for 12 weeks, patients were classified into several groups according to iron status, serum aluminum levels and i-PTH levels. Indivisualized treatments were performed: increased iron supplement for absolute iron deficiency, active vitamin D3 for secondary hyperparathyroidism and desferrioxamine(DFO, 5 mg/kg t.i.w.) for aluminum intoxication or hyperferritinemia. Results: 1) Result of IVAA therapy for 12 weeks on all patients(n=72). Hemoglobin levels at 2, 4, 6 week were significantly elevated compared to baseline, but those of hemoglobin at 8, 10, 12 week were not significantly different. 2) Result of IVAA therapy for 20 weeks on patients with 100 ${\mu}g/l$ ${\leq}$ ferritin < 500 ${\mu}g/l$ and transferrin saturation(Tsat) below 30%(n=30). After treatment of IV AA for 12 weeks, patients were evaluated the response of therapy according to iron status. Patients with 100 ${\mu}g/l$ ${\leq}$ ferritin < 500 ${\mu}g/l$ and Tsat below 30% showed the most effective response. These patients were treated further for 8 weeks. Hemoglobin levels at 2, 4 week were significantly increased compared to baseline with significantly reduced doses of EPO at 2, 4, 6, 10, 12, 16, 20 week. Concomitantly significantly improvement of Tsat at 2, 6, 16, 20 week compared to baseline were identified. 3) Result of IVAA therapy for 12 weeks followed by DFO therapy for 8 weeks on patients with serum aluminum above 4 ${\mu}g/l$(n=12) Hemoglobin levels were not significantly increased during IVAA therapy for 12 weeks but dosages of EPO were significantly decreased at 2, 4, 6, 8 week during DFO therapy compared to pre-treatment status. Conclusion: IVAA can be helpful for the treatment of the anemia caused by functional iron deficiency and can reduce the dosage of EPO for anemia correction. And administration of low dose DFO, in cases of increased serum aluminum level, can reduce the requirement of EPO.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.6
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• pp.880-887
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• 1998

In order to study heat transfer characteristics of spray cooling for the purpose of uniform and soft cooling of high temperature surface a series of experiments for a hot horizontal copper flat plate was performed by downflow spray water using flat spray nozzle. Cooling curves were mea-sured under the various experimental conditions of flow rates and temperatures of cooling water Surface temperature surface heat fluxes and heat transfer coefficients of horizontal upward-facing flat surface were calculated with cooling curves measured at each radial positions near the cooling surface by TDMA method. Generally heat transfer characteristics for spray cooling is simi-lar to boiling phenomenon of pool boiling. The minimum heat flux(MHF) appear at the surface temperature of about ${\Delta}Tsat=250^{\circ}C$ and the critical heat flux(CHF) appear at about ${\Delta}Tsat=250^{\circ}C$.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.194-197
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• 2004

본 논문에서는 송전 계통사고 시 부하차단 이후 우리나라 2005년 계통에 대하여 전력계통안정화장치(Power System Stabilizer : PSS)의 영향 및 효과를 캐나다 Powertech Labs Inc.,의 TSAT(Transient Security Assesment Tool)을 이용하여 분석하였다. 모의를 위한 송전선로의 사고는 765kV 선로와 345kV 선로를 대상으로 하였으며, 8개의 모선에 대하여 상정 사고를 발생시켜 선로 차단 및 재투입을 고려하여 실시하였다. 본 연구에서 TSAT에 대한 기존의 전통적인 형태인 IEEEST type과 보다 정교한 이중구조를 가진 PSS2A type의 두 가지를 검토한 결과를 살펴보면 절반의 경우가 발전단 인근 지점의 사고시 발전기가 안정을 회복하지 못하고 탈조하는 것으로 나타났다. 그 외의 지역의 모선 단의 PSS투입효과는 비교적 댐핑 효과가 있는 것으로 나타났다.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.605-613
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• 2016

This study was investigated to effect of tongue strength and accuracy training (TSAT) on tongue strength, swallowing function, quality of life in chronic stroke patients with dysphagia. Eighteen chronic stroke patients with dysphagia participated in this study, and were allocated randomly to experimental(n=9) and control group(n=9). both group conducted to traditional dysphagia therapy, and experimental group was carried out additionally TSAT. TSAT performed using Iowa Oral Performance Instrument(IOPI), and was set up to 50%, 75%, 100% of maximum isometric tongue strength. Two groups received the treatment for five per weeks, eight weeks. Outcome measurements performed that Maximum Isometric Strength(MIS) was assessed by using IOPI for measure the tongue strength, and Swallowing Function Test(SFT) was used to assess the swallowing function. Swallowing-Quality of Life(SWAL-QOL) was used to evaluate quality of life related to swallow. In results of study, experimental group in comparison of change score between two group significantly improve than control group in anterior and posterior MIS, and SFT. SWAL-QOL was not significantly difference in both group. Based on thin study results, TSAT may be a effective intervention to improve on tongue strength, and swallowing function in chronic stroke patients with dysphagia.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.4
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• pp.299-305
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• 2013

The complexity and severe nonlinearity of multi-machine power systems make it difficult to design a control input for voltage regulation using modern control theory. This paper presents a model-based PID control scheme for the regulation of the bus voltage to a desired value. To this end, a fourth-order linear system is constructed using input and output data obtained using the TSAT (Transient Security Assessment Tool); the input is assumed to be applied to the grid through the STATCOM (STATic synchronous COMpensator) and the output from the grid is a bus voltage. On the basis of the model, it is identified as to which open-loop poles of the system make the response to a step input oscillatory. To reduce this oscillatory response effectively, a model-based PID control is designed in such a way that the oscillatory poles are no longer problematic in the closed loop. Simulation results show that the proposed PID control dampens the response effectively.

• Journal of Satellite, Information and Communications
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• v.4 no.1
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• pp.1-7
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• 2009

As the information age comes out, the aspect of future war brings about the many changes in terms of war-fighting environment. Accordingly, information superiority and intelligence-centric warfare have been important and new war-fighting concept such as NCW(network centric warfare) have been turned up. This paper proposed all-weather core-strategy communications systems guaranteeing not only the real-time transmission of the information collected in a battlefield and expansion, automation, and rapidity of a battlefield but also broadband, mobility, survivability, and flexibility. The proposed military satellite communications system is classified into wideband mass capacity link, survivability, and the system supporting OTM(on the move) communication for the real-time transmission of battlefield information. This paper analyzed the essential operation concepts and core schemes of the U.S. Army's next generation system, TSAT(Transformational Satellite Communication System). Base on the analysis results, this paper proposed that the architecture of next generation military satellite communications systems for NCW have to provide the data rate, anti-jamming capability, network control and management capability which are optimally adaptable for the wireless channel environments such as jamming and interference and to support the variety of platforms like high-speed mobile vehicles, micromini devices, super-high speed unmanned aerial vehicles. Finally, this paper also proposed that next generation military satellite communications systems need the technologies such as the adaptable multi-antenna, laser link, and next-generation anti-jamming waveform.