• Title/Summary/Keyword: Abnormal return

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Study on Performance of an Fuel Pressure Regulator under Failure Condition in an Electric Control Diesel Engine (전자제어 디젤엔진의 연료압력 레귤레이터 고장에 따른 진단 및 성능 연구)

  • Kim, Tae-Jung;Cho, Hong-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.1677-1683
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    • 2015
  • To cope with exhaust gas regulation, Diesel engine applied to electronic control system. As it accurately regulated the injected fuel mass and the fuel efficiency and the output are increased but the noise and the vibration are decreased. In order to keep the performance of Electronic Diesel Control System, it is important to accurately control the fuel pressure. However, when the regulator of fuel pressure is not controlled properly, the failure phenomenons(starting failure, staring delay, accelerated failure, engine mismatch et al.) occur because the fuel pressure is not stabilize. In this study, effects on a fuel pressure, engine rotating speed according to the control rate of fuel-pressure regulator are investigated in order to analyzed the performance variation with failure of fuel-pressure regulator. As a result, when the control rate of a fuel-pressure regulator is 4%~6% lower than that of standard condition, the variation of engine's rpm and return fuel flow is increased, and the abnormal condition was occurred. Besides, it is possible to diagnose the failures on fuel-pressure regulator under these conditions.

Estimation of the Probability Flood Discharge for Small and Middle Watersheds (중소하천 유역에서의 확률홍수량 분석)

  • Yun, seong-jun;Yu, ui-geun;Kim, byeong-chan;Lee, jong-seok
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.442-448
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    • 2009
  • Recently, the natural disaster has occurred as a heavy snow fall, drought and flood by abnormal weather. The damage of human and property by flood is most serious problem among those natural disaster. In order to prepare structural or non-structural measure, to estimate exact flood discharge is important element. This study analyze frequency of hour-unit rainfall data and estimate probability flood discharge by HEC-HMS as changing method of runoff analysis. Also, this study analyze the peak flood discharge sensibility according to Curve Number(CN) with the return period. As a result of estimation of probability flood discharge with the variety CN, to select Antecedent Moisture To select suitable condition(AMC) is important parameter because flood discharge is estimated 40% gap according to AMC.

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Revision of Failed Shoulder Instability Repair (실패한 견관절 불안정증의 봉합술에 대한 재수술)

  • Park, Jin-Young;Park, Hong-Geun;Oh, Jeong-Hwan
    • Journal of the Korean Arthroscopy Society
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    • v.10 no.2
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    • pp.135-140
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    • 2006
  • Diagnosis and treatment of the unstable shoulder is one of the more difficult problems in orthopaedic surgery. There is confusion between the normal laxity with translation and subluxation of the humeral head relative to the glenoid and an abnormal amount of laxity, leading to pain and dysfunction. Unfortunately, there is no single treatment that applied to all lesions that cause the instability. It is imperative, therefore, that an accurate diagnosis be made, including the directions and degree of shoulder instability as well as any coexisting problems. Anatomical defects must be defined. Common factors that could most readily compromised instability repair are examined. These include techniques for making an accurate diagnosis with identification of the precise anatomical pathology, and the rationale for appropriate surgical treatment with the avoidance of technical complication such as unnecessary hardware or exposures that might lead to residual instability, arthritis, and nerve or vascular injuries. Additional injuries may be prevented by careful rehabilitation postoperatively to restore shoulder stability, flexibility, and endurance prior to an individual's return to stressful sports or work.

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A Study on the Firm Performance Following the Resolution of Investors Information Asymmetry in the Globalized Financial Market (글로벌금융시대의 투자자 정보불균형 해소에 따른 기업성과에 대한 연구 -국내외 기업의 IR공시가 주가에 미치는 영향을 중심으로-)

  • Kim, Kyu-Hyong;Park, Sa-Ngan
    • International Commerce and Information Review
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    • v.7 no.4
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    • pp.325-349
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    • 2005
  • One aspect of the globalization of the financial market after the 1980s is represented by the concurrent monetarization of the national stock markets. As the IR activity is regarded as a new financial productivity measure, the IR activity in the stock market is being emphasized domestically and internationally. This study analyzes domestic IR activities and compares them with foreign IR activities. Specifically the "road show", a typical IR activity, which is known to resolve the information asymmetry between the firm and the investors is analyzed to see the extent of the their value increase impact on the firm. The study employs domestic and international firms that publicly announced "road shows" after April 2004. Event studies are done to see the existence of abnormal return after the public announcement of road shows. Domestic firms were found to have positive IR impacts on the stock prices, but international firms were found to have negative IR impacts on the stock prices. Also it was found that international public announcement of the road show have stronger positive impact on the stock price than domestic public announcement. The investigation of the statistically significant difference of CAR before and after the fair public announcement enforcement rule showed that the positive CAR impact is strengthened after the adoption of the rule. The conclusion is that increase of the firm value after the road show implies that the information asymmetry is reduced by the active IR actions on the firm side. The policy implication is that we have to reassure the understanding of the role of the IR activities. Specifically Korean firms may have to encourage IR activities to share the information of the firms with the investors, which may result in the trustworthy relationship between the firms and investors.

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Real-Time Estimation of Control Derivatives for Control Surface Fault Detection of UAV (실시간 조종미계수 추정에 의한 무인비행기 조종면 고장검출)

  • Lee, Hwan;Kim, Eung-Tae;Choi, Hyoung-Sik;Choi, Ji-Young;Lee, Sang-Kee
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.11
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    • pp.999-1005
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    • 2007
  • In case of an abnormal condition of control surface, the real-time estimation of aerodynamic derivatives are required for the reconfigurable control system to be flight for missions or return to the head office. The goal of this paper is to represent a technique of fault detection to the control surface as a base research to the fault tolerant control system for safety improvement of UAV. The real-time system identification for the fault detection to the control surface was applied with the recursive Fourier Transform and verified through the HILS and flight test. The failures of the control surface are detected by comparing the control derivatives in fault condition with the normal condition. As a result from the flight test, we have confirmed that the control derivatives of fault condition less than about 50% in the normal condition.

The Expressive Characteristics of the Posthuman Body in Fashion Illustration (패션 일러스트레이션에 반영된 포스트휴먼의 신체 표현특징)

  • Choi, Jung-Hwa
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.9
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    • pp.1085-1098
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    • 2011
  • In the $21^{st}$ century, technology is a tool for the expansion of the five senses and physical ability that works as an element for posthuman identity. This study analyzes and theorizes on the characteristics of the posthuman body in fashion illustration. The method of this study analyzes documentaries about posthuman and fashion illustration. The results are as follow. Posthuman body types are classed as hybrid body, plastic surgery body, and digital body. The characteristics of the posthuman body are categorized as ultra- functional prosthetic, mythical undifferentiated, radical plastic surgery type and post-physical digitization type. The ultra-functional prosthetic type shows a restored body and upgraded functional body through a machine hybrid, cyborg suit and mannequin hybrid. It is a break from classical gender identity to form a nerve sense extension that displays physical and abstract power. The mythical undifferentiated type shows a therianthropic form, parts of an animal body, radical skin and gender bending. It represents the return to an undifferentiated world, the desire of a powerful being and the possibility of radical transformation. The radical plastic surgery type shows a photomontage of an ideal body, transgendered body, grotesque body marking, absence of partial or overall face organ and the expansion of abnormal body organs. It represents the expression of narcissism, unconscious desire, fantasy, fear and suggests an alternative ideality, sexual attachment and ambiguous gender identity. The post-physical digitization type shows an imperfect form or duplicated ego image through the omission of the body silhouette or detailed form, fragmented image using net, representative self like optical illusion using typography, an imperfect vague silhouette and immaterial body outline through the use of virtual light. It represents the lack of desire, narcissism, fluidity in a virtual space, the continued creation of a new self, ambiguous gender identity and the liberation of environment, sex, and race. Likewise, the posthuman in fashion illustration shows the absence of a species boundary, destruction of classical gender identity, a new personality and virtual self image.

Three-Phase Bone Scintigraphy in Reflex Sympathetic Dystrophy Syndrome of the Hand (반사성 교감신경계 기능장애 증후군(RSDS)의 손 3상 골스캔 소견)

  • Ahn, Myeong-Im;Park, Jeong-Mi;Park, Young-Ha;Kim, Sung-Hoon;Chung, Soo-Kyo;Shinn, Kyung-Sub;Bahk, Yong-Whee
    • The Korean Journal of Nuclear Medicine
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    • v.25 no.1
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    • pp.81-86
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    • 1991
  • Reflex sympathetic dystrophy syndrome (RSDS), known also as Sudeck's atrophy, is an uncommon disorder recognized by its distinctive symptom complex consisting of pain and tenderness, vasomotor instability, swelling, and dystrophic skin changes and radiologic changes. The present study has been carried out to prospectively establish scintigraphic diagnostic criteria for RSDS using three-phase radionuclide bone scintigraphy (TPBS). In addition, the usefulness in the evaluation of treatment of RSDS was assessed. Patients included were 6 men and 7 women with the age ranging from 25 to 63 years (average 47 years). Diagnosis was based on typical clinical symptoms and signs as described above. Associated clinical conditions in these patients were cerebral infarction (4 patients), lung cancer (2 patients), trauma (1 patient), lymphoma (1 patient), and unknown cause (5 patients). All patients showed diffuse radionuclide accumulation in juxtaarticular region on the delayed static image and 11 patients showed diffusely increased activities also on scintiangiogram and blood-pool image. Fillow-up TPBS after corticosteroid therapy in 4 patients revealed near normal return of abnormal radionuclide accumulations in the affected hand. TPBS is an useful test for the diagnosis of as well as the evaluation of the therapeutic effects of RSDS.

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Cause Analysis of Flow Accelerated Corrosion and Erosion-Corrosion Cases in Korea Nuclear Power Plants

  • Lee, Y.S.;Lee, S.H.;Hwang, K.M.
    • Corrosion Science and Technology
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    • v.15 no.4
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    • pp.182-188
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    • 2016
  • Significant piping wall thinning caused by Flow-Accelerated Corrosion (FAC) and Erosion-Corrosion (EC) continues to occur, even after the Mihama Power Station unit 3 secondary pipe rupture in 2004, in which workers were seriously injured or died. Nuclear power plants in many countries have experienced FAC and EC-related cases in steam cycle piping systems. Korea has also experienced piping wall thinning cases including thinning in the downstream straight pipe of a check valve in a feedwater pump line, the downstream elbow of a control valve in a feedwater flow control line, and failure of the straight pipe downstream of an orifice in an auxiliary steam return line. Cause analyses were performed by reviewing thickness data using Ultrasonic Techniques (UT) and, Scanning Electron Microscope (SEM) images for the failed pipe, and numerical simulation results for FAC and EC cases in Korea Nuclear Power Plants. It was concluded that the main cause of wall thinning for the downstream pipe of a check valve is FAC caused by water vortex flow due to the internal flow shape of a check valve, the main cause of wall thinning for the downstream elbow of a control valve is FAC caused by a thickness difference with the upstream pipe, and the main cause of wall thinning for the downstream pipe of an orifice is FAC and EC caused by liquid droplets and vortex flow. In order to investigate more cases, additional analyses were performed with the review of a lot of thickness data for inspected pipes. The results showed that pipe wall thinning was also affected by the operating condition of upstream equipment. Management of FAC and EC based on these cases will focus on the downstream piping of abnormal or unusual operated equipment.

A Study on the Performance of the M&A Firm in KOSDAQ (코스닥시장 M&A기업의 성과에 관한 연구)

  • Kim, Kyung-Sik
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.1 s.45
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    • pp.219-229
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    • 2007
  • The results of the research in M&A firms in the KOSDAQ market are as follows. First, the effect of the M&A disclosure at the time of disclosure was that the positive (+) cumulative abnormal return (CAR) can be interpreted as an increase in the value of the firm; however, in the long run, firms which used the KOSDAQ index and the control firm, which did not use the index were found to have conflicting results. Second, the findings show that the rise in value of general firms resulting from a M&A were higher that those of venture firms. Third, in testing the performance extrapolation hypothesis, it was shown that the performance of "value" firms (firms with a high B/M ratio but poor performance in the past) was better after a M&A than those of the "glamour" firms and that the performance extrapolation hypothesis was substantiated. Fourth, it can be construed that a size effect in a merger exists. The CAR of the small firms surpasses those of large firms. Fifth, in verifying operating performance, most variables showed a positive (+) value at the time of M&A but showed a negative (-) value after a M&A. These results show that because on the Korean KOSDAQ market, M&A are approached from a financial rather than an economic aspect, it can be inferred that it lowers the firms value.

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The Treatment of Gynecomastia using Ultrasound-Assisted Liposuction with Pull-Out Method or Excision through Periareolar Incision (다양한 술식을 이용한 여성형 유방증의 치료: 초음파 지방흡입술과 풀아웃법 또는 유륜절개를 통한 절제술)

  • Sim, Hyung Bo;Yoon, Sang Yub
    • Archives of Plastic Surgery
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    • v.34 no.2
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    • pp.237-242
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    • 2007
  • Purpose: Gynecomastia is an abnormal increase in the volume of the male breast. Patients affected by gynecomastia with significant glandular enlargement may respond to suction alone and/or sharp dissection and excision. The purpose of this report is to introduce the indications and results of authors' two techniques. Methods: The diameter of parenchyme was determined by a pinch test after liposuction. For the parenchymal diameter less than 4 cm, ultrasound-assisted liposuction was performed, in conjunction with the "pull-out technique" to effectively remove the fibrofatty tissue of the male breast through a single 5-7 mm incision. For the parenchymal diameter more than 4 cm, ultrasound-assisted liposuction and excision were applied through 2.5 cm periareolar approach. Results: A total of 94 patients (185 breasts) underwent the operation from October 2000 to October 2003 and mean follow-up period was 12 months. The volume of aspirates ranged from 50 to 450 cc per breast. There were no major complications such as skin flap necrosis. Five reoperations were performed for 1 hypertrophic scar, 2 under-resected and 2 hematoma cases. The patient's satisfaction was high and most of them were pleased with the shape of the breasts and scars. Conclusion: These procedures can minimize scars and reduce the incidence of contour problem such as saucer deformity, and provides consistent results. Patients can return to full activities in 48 hours. It can be offered as an option for the treatment of gynecomastia.