• Title/Summary/Keyword: Internal and External Characteristics

Search Result 889, Processing Time 0.022 seconds

Off-Line Parameter Identification of Permanent Magnet Synchronous Motor Using a Goertzel Algorithm

  • Yoon, Jae-Seung;Lee, Kyoung-Gu;Lee, June-Seok;Lee, Kyo-Beum
    • Journal of Electrical Engineering and Technology
    • /
    • v.10 no.6
    • /
    • pp.2262-2270
    • /
    • 2015
  • Generally, internal parameters of the motors and generators can be divided to the resistance and inductance components. They can become a cause of the changing internal parameters because they have sensitive characteristics due to external conditions. The changed parameters can generate the outputs which include error values from the speed and current controllers. Also, it can bring the temperature increase and mechanical damage to the system. Therefore, internal parameters of the motors and generators need to obtain their values according to the external conditions because it can prevent the mechanical damage caused by the changed parameters. In this paper, the off-line parameter identification method is verified using the Goertzel algorithm. The motor used in the simulation and experiments is an interior permanent magnet synchronous motor (IPMSM), and the proposed algorithm is verified by the simulation and experimental results.

Case Study on the Characteristics of Vertical Bearing Capacity for Steel Pipe Pile Installed by PRD (PRD 강환 말뚝의 연직지지력 특성에 관한 사례 연구)

  • 최용규;정창규;정성기;김동철;정태만
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 1999.03a
    • /
    • pp.225-232
    • /
    • 1999
  • Construction case of PRD (Percussion Rotary Drill) pipe pile and matters to be attended in construction of PRD pile were reviewed. The compressive and uplifting static pile load tests for PRD piles were performed and, also, analysis by Pile Driving Analyzer was done. Based on these results, bearing components in each resisting part (that is: steel toe, external skin, and internal skin) were measured separately. The measured resisting force was compared to the value calculated by the estimated formula. The pile capacity was mobilized in steel toe area and the external skin friction and the internal friction were not produced. Thus, it could be considered that toe of PRD pile should be supported in hard bearing stratum (for example, the fresh soft rock).

  • PDF

The external and internal morphological standards of original plants and herbal states in two kinds of Rhei Rhizoma (2종(種) 대황(大黃)의 외부(外部) 및 내외부형태(內外部形態))

  • Kim, Ja-Young;Choi, Go-Ya;Kim, Hong-Jun;Ju, Young-Sung
    • Korean Journal of Oriental Medicine
    • /
    • v.12 no.1
    • /
    • pp.39-48
    • /
    • 2006
  • The Following is a list of specific external and internal morphology of Rheum palmatum L. and R. undulatum L. in Rhei Rhizoma. 1. For the original plants of Rhei Rhizoma in the literatures. 18 plants are reported. 2. The external characteristics of original plant : R. palmatum has a large palmate leaf, its petiole of radical leaf has a simple bristle and its flower is purple and pink color. Whereas R. undulatum has a medium ovate leaf, its petiole of radical leaf is purphish, its stem leaf surrounds a half of stem and its flower is yellowish white color. 3. The character of herbal states : a. diameter and size-- R. palmaum is bigger and heavier than R. undulatum. b. in section--R. palmatum is dark brown color, R. undulatum is bright brown color Fibrovascular bundle is arranged in circle shape in R. patmatum. R. undulatum shows a distingushed wheel shape. 4. The internal characteristics : R. palmatum has a large intercellular space of cork layer, its cambium is clear and a xylem medullary ray is comparatively tight, Whereas R. undulatum has a tight intercettular space of cork layer., its cambium is a few clear and xylem medullary ray is verty tight. As these results, additional study is required to distinguish herbs and their effect among many kinds of same genus-degree of relatedness.

  • PDF

A Study on the Identification Technique and Prevention of Combustion Diffusion through ESS (Energy Storage System) Battery Fire Case (ESS (에너지 저장장치) 배터리 화재사례를 통한 감식기법 및 연소 확산방지에 관한 연구)

  • Lee, Jung-Il
    • Journal of the Society of Disaster Information
    • /
    • v.16 no.2
    • /
    • pp.383-391
    • /
    • 2020
  • Purpose: To identify internal self ignition and ignition caused by external flames in energy storage rooms, and to analyze the difference between ignition due to overheating and ignition caused by external heat sources. Method: membrane melting point measurement, battery external hydrothermal experiment, battery overcharge experiment, comparative analysis of electrode plate during combustion by overcharge and external heat, overcharge combustion characteristics, external hydrothermal fire combustion characteristics, 3.4 (electrode plate comparison) / 3.5 (overcharge) /3.6 (external sequence) analysis experiment. Result: Since the temperature difference was very different depending on the position of the sensor until the fire occurred, it is judged that two temperature sensors per module are not enough to prevent the fire through temperature control in advance. Conclusion: The short circuit acts as an ignition source and ignites the mixed gas, causing a gas explosion. The electrode breaks finely due to the explosion pressure, and the powder-like lithium oxide is sparked like a firecracker by the flame reaction.

Development of Ozone Generation Technology Using Gaseous Electrical Discharge for Environment Improvement (환경개선용 기체전기방전을 이용한 오존발생기술 개발)

  • 이동헌;송현직;구건효
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.15 no.3
    • /
    • pp.25-34
    • /
    • 2001
  • In this paper, discharge lamp ozonizer(DLO) of a new discharge type using superposition of gaseous electrical discharge for environment improvement was designed and manufactured. DLO is equipped with 3 electrodes(central ground electrode of discharge lamp type internal high voltage electrode of mesh type and external high voltage electrode of spiral type), and it is composed of double gap(gap between discharge lamp and internal electrode, gap between discharge lamp and external electrode). Internal and external electrodes are respectively applied AC high voltage which has 180[$^{\circ}$] phase difference. Ozone is generated by overlaying of each silent discharge which is respectively came from two gaps. At the moment discharge characteristics and ozone generation characteristics of DLO were investigated in accordance with quantity of supplied gas, discharge power and the number of DLO. When ozone generated by DLO was in contact with NO gas, removal characteristics was excellent, so it confirmed that DLO could be used as air environment improvement facility.

  • PDF

An Exploratory Study of IT Adoption Factors' Performance: Considering Internal and External factors in SMEs' ERP (IT 도입요소의 성과에 관한 탐색적 연구: 중소기업 ERP의 내.외부 도입요소를 중심으로)

  • Lee, Jong Moo
    • Journal of Korea Society of Digital Industry and Information Management
    • /
    • v.8 no.4
    • /
    • pp.205-215
    • /
    • 2012
  • Due to a rapid change of business environment, many firms are eager to find the competitiveness by information technology adoption and diffusion. In this exploratory study, we examined the applicability of a previously proposed model to evaluate IT competitiveness based on the innovativeness and verified it's propriety with empirical data. As suggested by previous studies, the proposed model considers a variety of corporate and market characteristics concerned with IT adoption, and it consists of several internal and external impacting factors, which have influence on technology diffusion and its performance. For the empirical analysis, the survey data of domestic ERP adoption cases were adopted from 128 small and medium-sized enterprises(: SMEs) in IT and electrical engineering industry, and analyzed by partial least squares(: PLS) - a popular structural modeling and multivariate projection technique to latent variables. The results indicated positive supports for the research model of external and internal IT adoption factors' influences on innovativeness' performances. However, there are a couple of limitations not to show the reliability of selected measurement items and the generality of model proposed in this exploratory study.

The Effects of Project Newness on the Relationship between Project Management Styles and Performance (프로젝트의 신규성 정도가 프로젝트 관리방식과 성과간의 관계에 미치는 영향)

  • Park, O-Wwon;Cha, Jong-Seok;Kim, Sun-Woo
    • Journal of Korea Technology Innovation Society
    • /
    • v.15 no.2
    • /
    • pp.421-442
    • /
    • 2012
  • Many studies have been published on the relationship between project management styles and project performance. In recent researches, it is argued that project management styles should be different based on project characteristics and these project characteristics may have an effect on the relationship between project management styles and project performance. However, there are few empirical studies covering these issues. In this study, we examined the effect of project characteristics (i.e., degree of newness) on the relationship between project management styles (i.e., team autonomy, internal and external communication, individualism orientation) and project performance. The empirical results using 78 government sponsored R&D projects showed that team autonomy has a stronger positive effect on project performance as project newness becomes higher. In addition, as project newness becomes higher, internal communication showed a stronger positive effect on project performance, while external communication had a stronger negative effect.

  • PDF

A Study on the Effects of Business Environment upon Corporate Image (외식업체의 영업 환경이 기업 이미지에 미치는 영향)

  • Yoo, Kyung-Hin
    • Culinary science and hospitality research
    • /
    • v.11 no.4 s.27
    • /
    • pp.30-45
    • /
    • 2005
  • This study is to explore the effects of business environment upon corporate image. Customers of foodservice establishments are selected as a population and six famous family restaurants located in Seoul were selected to evaluate the population. Accordingly, the purpose of the study is to survey satisfaction with corporate image of foodservice establishments and six famous family restaurants, to evaluate the satisfaction with corporate image, and to find a plan of raising corporate image. 240 samples were distributed and 194 samples were collected among them. 182 valid samples were selected for the research. As a result of factor analysis for business environment, internal environment factor, external environment factor, addition environment factor were extracted. There was no significant difference by sen, age, schooling, occupation, average income by month, and number of visiting foodservice establishments after examining the difference of establishment business environment by demographic characteristics. Analysing the effects of business environment upon corporate image revealed that the effects of business environment had effects upon corporate image in order of internal environment factor(.531), external environment factor(.360), and addition environment factor(.285).

  • PDF

A Study on the Gagamjeong-gisan in the Onbyeongjobyeon - In Comparison with the Gwakhyangjeong-gisan - (『온병조변(溫病條辨)』 에 나타난 가감정기산(加減正氣散)에 대한 고찰 - 곽향정기산(藿香正氣散)과의 비교를 중심으로 -)

  • Kim Sanghyun;Kim Jong-hyun
    • Journal of Korean Medical classics
    • /
    • v.36 no.2
    • /
    • pp.77-96
    • /
    • 2023
  • Objectives : The purpose and application method of the five kinds of Gagamjeong-gisan in the Onbyeongjobyeon were analyzed and their significance was examined. Methods : First, contents within medical texts on the Gwakhyangjeong-gisan, the original formula for the Gagamjeong-gisan were analyzed. Next, application, symptoms and pathogenic mechanism, treatment principle, composition of the Gagamjeong-gisan as written in the Onbyeongjobyeon were analyzed. Characteristics of each formula as deduced from this process were compared and examined. Results : The Gwakhyangjeong-gisan covers both external contraction and internal damage, applied regardless of external or internal symptoms. It restores the Yang qi of the Spleen and Stomach, balancing the Zheng qi to respond to the external qi. The Gagamjeong-gisan takes after the Gwakhyangjeong-gisan, reflecting such properties. However, the latter differs in that it excludes ingredients unfit for treating dampness-warmth, and uses different application methods according to the level of discharge of dampness pathogen. Conclusions : The Gagamjeong-gisan is modified from the Gwakhyangjeong-gisan, which is applied to cold damage and internal damage to better treat warm disease. It can be said to have acted as a bridge for warm disease scholars in composing formulas that deal with dampness-heat disease.

Experimental Study on the Internal Flow Characteristics in a Swirl Coaxial Injector for Gas Generator (가스발생기용 스월 동축형 인젝터에서 내부 유동의 특성에 대한 실험적 연구)

  • Kim, Sung-Hyuk;Yoon, Jung-Soo;Yoon, Young-Bin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2010.05a
    • /
    • pp.29-33
    • /
    • 2010
  • This study aim to investigate the internal flow characteristics by recess length of swirl coaxial injector for gas generator has propellant of Kerosene-LOx. Recess length is a very important element, have influence in spray stability and LOx post damage. The influence of recess length was analyzed by visualizing internal flow and measuring liquid film thickness and manifold pressures. Also, each spray characteristic by recess length was investigated in internal or external injector.

  • PDF