• Title/Summary/Keyword: peak factors

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A Study on the Peak Load Prediction for Molter-use Distribution Transformer (동력용 배전 변압기의 최대부하 예측 개선 방안에 관한 연구)

  • Park, Kyung-Ho;Kim, Jae-Chul;Yun, Sang-Yun;Lee, Young-Suk;Park, Chang-Ho
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.530-532
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    • 2002
  • The contracted electric power and the demand factor of customers are used to predict the peak load in distribution transformers. The conventional demand factor was determined more than ten years ago. The contracted electric power and power demand have been increased. Therefore, we need to prepare the novel demand factor that appropriates at present. In this paper, we modify the demand factor to improve the peak load prediction of distribution transformers. To modify the demand factor, we utilize the 169 data acquisition devices for sample distribution transformers. The peak load currents were measured by the case studies using the actual load data, through which we verified that the proposed demand factors were correct than the conventional factors. A newly demand factor will be used to predict the peak load of distribution transformers.

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Improvement Method of Peak Load Forecasting for Mortor-use Distribution Transformer by Readjustment of Demand Factor (호당 수용률 조정을 통한 동력용 배전 변압기 최대부하 예측 개선 방안)

  • Park, Kyung-Ho;Kim, Jae-Chul;Lee, Hee-Tea;Yun, Sang-Yun;Park, Chang-Ho;Lee, Young-Suk
    • Proceedings of the KIEE Conference
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    • 2002.11b
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    • pp.41-43
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    • 2002
  • The contracted electric power and the demand factor of customers are used to predict the peak load in distribution transformers. The conventional demand factor was determined more than ten years ago. The contracted electric power and power demand have been increased. Therefore, we need to prepare the novel demand factor that appropriates at present. In this paper, we modify the demand factor to improve the peak load prediction of distribution transformers. To modify the demand factor, we utilize the 169 data acquisition devices for sample distribution transformers in winter, spring summer. And, the peak load currents were measured by the case studies using the actual load data, through which we verified that the proposed demand factors were correct than the conventional factors. A newly demand factor will be used to predict the peak load of distribution transformers.

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Investigation on Effective Peak Ground Accelerations Based on the Gyeongju Earthquake Records (경주지진 관측자료에 기반한 유효최대지반가속도 분석)

  • Shin, Dong Hyeon;Hong, Suk-Jae;Kim, Hyung-Joon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.7_spc
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    • pp.425-434
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    • 2016
  • This study investigates important parameters used to determine an effective peak ground acceleration (EPGA) based on the characteristics of response spectra of historical earthquakes occurred at Korean peninsula. EPGAs are very important since they are implemented in the Korean Building Code for the seismic design of new structures. Recently, the Gyeongju earthquakes with the largest magnitude in earthquakes measured at Korea took place and resulted in non-structural and structural damage, which their EPGAs should need to be evaluated. This paper first describes the basic concepts on EPGAs and the EPGAs of the Gyeongju earthquakes are then evaluated and compared according to epicentral distances, site classes and directions of seismic waves. The EPGAs are dependant on normalizing factors and ranges of period on response spectrum constructed with the Gyeongju earthquake records. Using the normalizing factors and the ranges of period determined based on the characteristics of domestic response spectra, this paper draw a conclusion that the EPGAs are estimated to be about 30 % of the measured peak ground accelerations (PGA).

The Incidence, Associated Factors and Clinical Impact of Hyperamylasemia in Self-poisoning Patients (중독 환자에서 고아밀라아제혈증의 발생률, 관련 요인 및 임상적 영향)

  • Seo, Min Gu;Oh, Sang Hoon;Lim, Jee Yong;Kim, Han Joon;Choi, Se Min
    • Journal of The Korean Society of Clinical Toxicology
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    • v.14 no.2
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    • pp.83-91
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    • 2016
  • Purpose: This study was conducted to investigate the incidence, associated factors and clinical impact of hyperamylasemia in self-poisoning patients. Methods: This study was based on a toxicology case registry of patients treated from 2009 to 2013 at a tertiary care university hospital. We retrospectively investigated the demographics, clinical variables, laboratory variables and intoxicants. Hyperamylasemia was defined as an elevation in serum amylase level to above the upper normal limit within 24 hours after admission. We analyzed the predisposing factors and clinical outcomes of patients in the hyperamylasemia group. Results: Hyperamylasemia was identified in 49 (13.3%) of the 369 patients. Using multivariate logistic regression, the odds ratios for HA were 3.384 (95% confidence interval, 1.142-8.013, p=0.014), 3.261 (95% confidence interval, 1.163-9.143, p=0.025) and 0.351 (95% confidence interval, 0.154-0.802, p=0.013) for pesticides, multi-drug use and sedatives, respectively. In the hyperamylasemia group, the peak amylase levels during 72 hours were correlated with the peak lipase levels (r=0.469, p=0.002) and peak aspartate aminotransferase levels (r=0.352, p=0.013). Finally, none of these patients had confirmed acute pancreatitis. Conclusion: Hyperamylasemia occurred rarely in these self-poisoning patients, and pesticide and multi-drug use were independent predictors of hyperamylasemia. Peak amylase levels were correlated with the peak lipase and aspartate aminotransferase levels.

Derivation of response spectrum compatible non-stationary stochastic processes relying on Monte Carlo-based peak factor estimation

  • Giaralis, Agathoklis;Spanos, Pol D.
    • Earthquakes and Structures
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    • v.3 no.5
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    • pp.719-747
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    • 2012
  • In this paper a novel approach is proposed to address the problem of deriving non-stationary stochastic processes which are compatible in the mean sense with a given (target) response (uniform hazard) spectrum (UHS) as commonly desired in the aseismic structural design regulated by contemporary codes of practice. The appealing feature of the approach is that it is non-iterative and "one-step". This is accomplished by solving a standard over-determined minimization problem in conjunction with appropriate median peak factors. These factors are determined by a plethora of reported new Monte Carlo studies which on their own possess considerable stochastic dynamics merit. In the proposed approach, generation and treatment of samples of the processes individually on a deterministic basis is not required as is the case with the various "two-step" approaches found in the literature addressing the herein considered task. The applicability and usefulness of the approach is demonstrated by furnishing extensive numerical data associated with the elastic design UHS of the current European (EC8) and the Chinese (GB 50011) aseismic code provisions. Purposely, simple and thus attractive from a practical viewpoint, uniformly modulated processes assuming either the Kanai-Tajimi (K-T) or the Clough-Penzien (C-P) spectral form are employed. The Monte Carlo studies yield damping and duration dependent median peak factor spectra, given in a polynomial form, associated with the first passage problem for UHS compatible K-T and C-P uniformly modulated stochastic processes. Hopefully, the herein derived stochastic processes and median peak factor spectra can be used to facilitate the aseismic design of structures regulated by contemporary code provisions in a Monte Carlo simulation-based or stochastic dynamics-based context of analysis.

Derivation of response spectrum compatible non-stationary stochastic processes relying on Monte Carlo-based peak factor estimation

  • Giaralis, Agathoklis;Spanos, Pol D.
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.581-609
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    • 2012
  • In this paper a novel non-iterative approach is proposed to address the problem of deriving non-stationary stochastic processes which are compatible in the mean sense with a given (target) response (uniform hazard) spectrum (UHS) as commonly desired in the aseismic structural design regulated by contemporary codes of practice. This is accomplished by solving a standard over-determined minimization problem in conjunction with appropriate median peak factors. These factors are determined by a plethora of reported new Monte Carlo studies which on their own possess considerable stochastic dynamics merit. In the proposed approach, generation and treatment of samples of the processes individually on a deterministic basis is not required as is the case with the various approaches found in the literature addressing the herein considered task. The applicability and usefulness of the approach is demonstrated by furnishing extensive numerical data associated with the elastic design UHS of the current European (EC8) and the Chinese (GB 50011) aseismic code provisions. Purposely, simple and thus attractive from a practical viewpoint, uniformly modulated processes assuming either the Kanai-Tajimi (K-T) or the Clough-Penzien (C-P) spectral form are employed. The Monte Carlo studies yield damping and duration dependent median peak factor spectra, given in a polynomial form, associated with the first passage problem for UHS compatible K-T and C-P uniformly modulated stochastic processes. Hopefully, the herein derived stochastic processes and median peak factor spectra can be used to facilitate the aseismic design of structures regulated by contemporary code provisions in a Monte Carlo simulation-based or stochastic dynamics-based context of analysis.

New Approach to Investigate the Dynamic Relaxaton Process of Complex Peak in Mechanical and dielectric Characteristics of Anelastic Solids

  • Kim, Bong-Heup
    • Electrical & Electronic Materials
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    • v.11 no.10
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    • pp.1-5
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    • 1998
  • Complex dynamic relaxation processes of mechanical as well as dielectric character in polymeric anelastic solids are closely related through the movement of molecular chain segment in morphological structure, and the morphology can easily be modified by the treatments such as mechanical drawing or irradiation, those of which result, in turn, the complicated change on the appearance of the observed complex relaxation peak. In order to extract any meaningful understanding from the modified appearance of the peak, the relaxation peak must be resolved into the sum of the dynamic single relaxation peaks, each of which can be characterized respectively by three factors such as activation energy, magnitude of peak height and peak point temperature on the temperature dependent characteristics.

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Effects of walking speed on peak plantar pressure in healthy subjects (정상인에서 보행 속도가 발바닥의 최대압력분포에 미치는 영향)

  • Ha, Mi-Sook;Nam, Kun-Woo
    • Journal of Korean Physical Therapy Science
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    • v.22 no.2
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    • pp.43-47
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    • 2015
  • Background : Many factors affect foot and ankle biomechanics during walking, including gait speed and anthropometric characteristics. This study examined the effect of walking speed on peak plantar pressure during the walking. Method : Thirty two normal healthy subjects (16 men, 16 women) were recruited. Peak plantar pressure was investigated using pressure distribution platforms (Pedoscan system) under the hallux heads of the first, second, and third metatarsal bones, and heel. Result : The results also suggest that slow walking speeds may decrease forefoot peak plantar pressure in patients with peripheral neuropathy who have a high risk of skin breakdown under the forefoot(p<0.05). Conclusion : The results also suggest that slow walking speeds may decrease forefoot peak plantar pressure in patients with restricted low extremity range of motion who have a high risk of skin breakdown under the forefoot.

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Study on the pulse current control of the inverter TIG welder (인버터 TIG 용접기의 펄스전류 제어에 관한 연구)

  • 서문준;김규식;원충연;민명식;최규하;목형수
    • Proceedings of the KIPE Conference
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    • 1998.07a
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    • pp.154-157
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    • 1998
  • In this paper, the inverter TIG(Tungsten Inert Gas) welding system with high power efficiency by means of pulse current control of welding process is presented. In TIG welding, pulse current control is utilized in order to attain less apatter and high welding performance. The four factors which determine the welding performance of the pulse current are frequency, base current, peak current, and peak current duty current, and peak current duty ratio. In this paper, we analyze these factors should be controlled to achieve minimum power input. To demonstrate the practical significance of our results, we present some experimental results as well as simulation results.

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Effects of Abdominal Circumference, Blood Lipids and Blood Pressure according to Diabetes with VO2peak (당뇨 유·무에 따른 VO2peak가 복부둘레, 혈중지질 및 혈압에 미치는 영향)

  • Nam, Sang-Nam;Park, Jung-Beom;Lee, Hyoung-Ju
    • The Journal of the Korea Contents Association
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    • v.12 no.12
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    • pp.363-371
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    • 2012
  • This research is to know about how $VO_2peak$ effects on Abdominal circumference, Blood lipids and blood presure with diabetes patients. After that, we have reached the final decision. in terms of the patients, there is significant indication that Abdominal circumference and HDL-cholesterol are related to $VO_2peak$. And Non-patients and $VO_2peak$ are related to each other though. $VO_2peak$ of the patients significantly effects on Abdominal circumference. Also, $VO_2peak$ of Nom-patients are same in aspect of Diastolic blood pressure As for Abdominal circumference, $VO_2peak$, High-density lipoprotein (HDL) cholesterol, Triglyceride, blood pressure, they are significantly associated to each other For These reasons, we have suggested that $VO_2peak$ seems to be possible to be handled by monitoring index for dangerous factors. Futhermore, exercise is really regarded as the best way of improving Cardiopulmonary capacity.