• Title/Summary/Keyword: Front-End

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Assessment of FEED Structure and Functions for Project Management of Thermal Power Plant Construction (사업관리 관점의 FEED 업무 프로세스 구조 및 항목 평가 - 화력발전소를 중심으로 -)

  • Kim, Namjoon;Jung, Youngsoo;Yang, Myungdirk
    • Korean Journal of Construction Engineering and Management
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    • v.16 no.5
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    • pp.65-76
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    • 2015
  • FEED (Front End Engineering and Design) is the key area that determines the competitiveness of procurement and construction in the EPC contracts especially in terms of the added value. Nevertheless, previous researches in FEED have been limited to the process and deliverable of design work or the particular management business function (e.g. System Engineering, collaboration, information etc.). In this context, the purpose of this study is to propose a comprehensive FEED structure and its functions from the project management perspective throughout the whole project life-cycle for thermal power plants. Proposed FEED business procedures are classified into three levels; First level is the classification of FEED business phases, the second level defines major FEED management functions, and the third level is detailed FEED functions. A survey using proposed FEED functions and assessment variable was conducted in order to analyze the current status and the areas for future improvement. It is expected that the proposed structure, functions, and evaluation methodology for FEED management will contribute to effective practice of FEED as well as to improvement of competitive capability for engineering, procurement, and construction (EPC) companies.

Morphological Development of Eggs, Larvae and Juveniles of the Sterlet Sturgeon, Acipenser ruthenus (Pisces: Acipenseridae) (스텔렛 철갑상어 (Acipenser ruthenus)의 난 발생과 자치어 형태발달)

  • Park, Jae Min;Yoon, Seung Min;Seo, Young Seok;Han, Kyeong Ho;Yoo, Dong Jae
    • Korean Journal of Ichthyology
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    • v.28 no.3
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    • pp.179-185
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    • 2016
  • To develop cultivation technique for Acipenser ruthenus and secure basic taxonomic materials, this study examined egg development and larva morphological development. This study used a couple of male and female broodstork matured in a PVC circle water tank (Ø 5 m) with the water temperature of $16.0{\pm}1.0^{\circ}C$ in June 2005. They were oval opaque and sinking cohesive eggs and the sizes of them were between $3.83{\sim}3.85(3.84{\pm}0.01)mm$ (n=10). As for the egg development, the dry process was adopted with artificial insemination in this study, and an hour after the insemination, the embryo disks were developed, 31 hours after the insemination, they reached the end of gastrula stage, and 82 hours (50%) after the insemination, they were hatched. Right after the hatch, the total lengths of larvae were $10.1{\sim}10.3(10.2{\pm}0.11)mm$ (n=10) with big yolks in the venter. 17 days after the hatch, the total lengths of them were $26.2{\sim}32.4(29.3{\pm}4.39)mm$ (n=10) and in the front of a dorsal fin there were 11 scute scales that started to make tracing development. As 50 days after the hatch, the total lengths were $86.4{\sim}93.1(89.8{\pm}4.71)mm$ (n=10), and fin rays all reached integer, they were moved to the larva apparatus.

Design of a Broadband Receiving Active Dipole Antenna Using an Equivalent Model (등가 모델을 이용한 광대역 수신용 능동 다이폴 안테나 설계)

  • Lee, Cheol-Soo;Pack, Jeong-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.1
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    • pp.23-32
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    • 2008
  • In the VHF range, active antennas are widely used for wideband applications due to their small size. Active antenna consists of antenna elements and amplifiers, which are directly connected to each other. Gain and noise-figure characteristics are very important for good sensitivity performance, because it is located at the front end of a receiving system. In this study, we developed an active dipole antenna with 5:1 bandwidth(100${\sim}$500 MHz), which consists of a dipole antenna and a P-HEMT amplifier. To obtain required performances, the antenna and the amplifier should be designed simultaneously. In order for that, we introduced an equivalent port concept to model the 1-port dipole antenna as an equivalent 2-port system. Using the proposed equivalent port, the performance of the active dipole antenna was simulated by the ADS. In order to measure the gain and noise-figure characteristics of the antenna, we utilized the same concept of the two-port equivalent impedance model. The measurement results for typical gain, NF and VSWR in the required frequency band were 8dBi, 9dB and 1.7:1, respectively. The radiation patterns at the principal planes were same as the typical radiation pattern of a dipole antenna. By comparing the simulation results with measured ones, it is confirmed that the proposed methods works well.

Clinical Outcome in Gamma Knife Radiosurgery for Metastatic Brain Tumors from the Primary Breast Cancer : Prognostic Factors in Local Treatment Failure and Survival

  • Choi, Seung Won;Kwon, Do Hoon;Kim, Chang Jin
    • Journal of Korean Neurosurgical Society
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    • v.54 no.4
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    • pp.329-335
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    • 2013
  • Objective : Brain metastases in primary breast cancer patients are considerable sources of morbidity and mortality. Gamma knife radiosurgery (GKRS) has gained popularity as an up-front therapy in treating such metastases over traditional radiation therapy due to better neurocognitive function preservation. The aim of this study was to clarify the prognostic factors for local tumor control and survival in radiosurgery for brain metastases from primary breast cancer. Methods : From March 2001 to May 2011, 124 women with metastatic brain lesions originating from a primary breast cancer underwent GKRS at a tertiary medical center in Seoul, Korea. All patients had radiosurgery as a primary treatment or salvage therapy. We retrospectively reviewed their clinical outcomes and radiological responses. The end point of this study was the date of patient's death or the last follow-up examination. Results : In total, 106 patients (268 lesions) were available for follow-up imaging. The median follow-up time was 7.5 months. The mean treated tumor volume at the time of GKRS was 6273 $mm^3$ (range, 4.5-27745 mm3) and the median dose delivered to the tumor margin was 22 Gy (range, 20-25 Gy). Local recurrence was assessed in 86 patients (216 lesions) and found to have occurred in 36 patients (83 lesions, 38.6%) with a median time of 6 months (range, 4-16 months). A treated tumor volume >5000 $mm^3$ was significantly correlated with poor local tumor control through a multivariate analysis (hazard risk=7.091, p=0.01). Overall survival was 79.9%, 48.3%, and 15.3% at 6, 12, and 24 months, respectively. The median overall survival was 11 months after GKRS (range, 6 days-113 months). Multivariate analysis showed that the pre-GKRS Karnofsky performance status, leptomeningeal seeding prior to initial GKRS, and multiple metastatic lesions were significant prognostic factors for reduced overall survival (hazard risk=1.94, p=0.001, hazard risk=7.13, p<0.001, and hazard risk=1.46, p=0.046, respectively). Conclusion : GKRS has shown to be an effective and safe treatment modality for treating brain metastases of primary breast cancer. Most metastatic brain lesions initially respond to GKRS, though, many patients have further CNS progression in subsequent periods. Patients with poor Karnofsky performance status and multiple metastatic lesions are at risk of CNS progression and poor survival, and a more frequent and strict surveillance protocol is suggested in such high-risk groups.

심의고(深依考)

  • Kim, In-Suk
    • Journal of the Korean Society of Costume
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    • v.1
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    • pp.101-117
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    • 1977
  • This thesis is a study of the Simui(深衣) system which was a dress regulation peculiar to old China with skirt and coat. The origin of Simui is a very long time, that is, before Ju dynasty in China. Its wearing range had a large circle irrespective of rank and good or bad luck. This was a ordinary dress to the Emperor or the lords, a below court attire or a below sacrificial rites attire to the illustrious officials, and good luck dress to the common people. But this was a funeral rites attire or coming-of-age ceremony attire in domestic behaviour. In the times of Song dynasty, lots of confucian scholars had put on this simui because of Juhi's recommendation for domestic behaviour. This Simui had been put on through all the times of China and was the original text of all the dress. Especially the court attire and silkworm working dress of Empress, and the court attire and underwear court attire of Emperor is also made out of this Simui, therefore this is a origin of the ceremonial dress which formed into long coat. In Korea it is said that this Simui was brought in prior to the middle of Goryeo dynasty. But we can't tell the correct transmitted age. According to the following records in Goryeo History, "King had put on the Simui as a sacrificial rite attire in the times of Yejong". It is sure that this Simui was brought in prior to the times of Yejong. In fact, lots of confucian scholars had put on the Simui since the introduction of confucianism in the end of Goryeo dynasty and after that time this was taken by many confucian scholars through Yi dynasty. Korean Simui system was complied with Chinese system through confucian domestic behaviour, This was respected for court dress of confucian scholars, as it were, Chumri, (an ordinary dress of scholars), Nansam (a uniform of upper student), and Hakchangui (a uniform of confucian student). There are many deta about Simui system in the book of Yeki, chapter Okcho and Simui, and other many canfucian books. But we didn't demonstrate the theory about it till now. Especially there are diversifies of opinions about the phrase of "Sok Im Ku Byun" in Yeki. Simui was cut in separate and then was stitched together in one piece. Generally its shape had round sleeve and angled lapel, its length reaches to the anklebone. And it has a line around the lapel, the sleeve band, and the edge of skirt. It is called Simui because the body can be wrapped deeply in broad width and large sleeve. The Simui was made of white fine linen and was cut by the natural size of body. Every part of Simui had a profound meaning; the round sleeve in compliance with regulation can keep a courtesy when a walker moves his hands and the angled lapel like a carpenter's square in compliance with square keeps them front loosing their Justice and a string of the back also keeps them loosing from their righteousness and the flat lower part of Simui makes their heart and mind calm. This Simui was usually attendant on a head cover and belt made cloth, and black shoes. This thesis was made a study of documents and portrait from Yi dynasty, for the actual object was not obtained.

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A Study on the Development of Lightweight Seat Cushion Extension Module (경량형 시트 쿠션 익스텐션 모듈 개발에 관한 연구)

  • Jang, Hanseul;Choi, Seongkyu;Park, Sang-Chul;Lim, Heon-pil;Oh, Eu-Ddeum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.8
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    • pp.200-207
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    • 2016
  • The automotive seat is an important component that moves in sync with the driver and is actively being developed with various new functions. The aim of this work is to develop a lightweight seat cushion extension module using a lightweight material. To this end, a structural strength analysis, vertical strength test, and durability test were conducted. In the structural analysis, the maximum value of deformation under vertical load was 4.98 mm at the front of the upper panel. The maximum stress was approximately 105 MPa, which occurred at the point of contact between the upper and lower panels of the module. The vertical strength test showed a maximum vertical deformation of 5.31 mm under a vertical load, which differed from the analysis results by approximately 6.45%. The structural safety of the product was verified by the fact that it showed no harmful deformation or damage during operation after the vertical strength test and a durability test for 20,000 cycles. Furthermore, the use of engineering plastics made it possible to reduce the weight by approximately 30% compared to existing products. The lack of damage after tests verified the passenger safety, strength, and rigidity of the product. The results are expected to be applied for improving environmental and fuel efficiency regulations and preventing accidents due to driver fatigue. The applications of this module could be expanded various types of vehicles, as well as other industries in which eco-friendly and lightweight materials are used.

Scanning electron microscopic observations of Thezazia callipaeda from human (인체 기생 Thelatria cazlipaeda의 주사전자현미경적 관찰)

  • 최원영;윤지혜
    • Parasites, Hosts and Diseases
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    • v.27 no.3
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    • pp.217-224
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    • 1989
  • Four females and a male nematode isolated from 2 patients who visited eye clinics In Seoul were identified as Thelazia callipaeda and their ultrastructures were observed by scanning electron microscopy(SEM). General features of the worms were slender and attenuated at both ends. Vaginal opening was located at 0.27 mm from the anterior end, and in front of the esophagointestinal junction. In the body cuticle transverse striations varied characteristically through the body. The number of cuticular transverse striations was 400∼650/mm at head portion, 250/mm at middle portion and 300∼350/mm at tail portion. The SEM observation of the mouth part of the females showed 6 cord-like cuticular thickenings in hexagonal arrangement and an amphid was observed. A lateral line, a vaginal opening, a pair of phasmids, and an anus were identified in the body portion. A pair of papillae and 6 cord-like cuticular thickenings were on the mouth part of the male. It was difficult to observe structures at the tail of the male except wrinkle-like structures. Most of the larvae isolated from the uterus of a female worm were sheathed and thus cuticular striations were not Eren. Others were unsheathed and revealed cuticular striations. The oval membrane which encysted sheathed larvae was also observed. These are the 18th and 19th record of human thelaziasis in Korea as the literature are concerned.

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Project Risk Assessment Through Construction Sequence Analyses for Industrial Plant Construction Projects (산업플랜트 건설 프로젝트의 주요 공정 시퀀스 분석을 통한 리스크 평가)

  • Lee, Kyusung;Choi, Jaehyun
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.4
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    • pp.140-151
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    • 2013
  • In 2011 and 2012, Korean construction firms awarded around $ 64.5. Billion each year from the overseas market in 2011. This contract value accounted for overwhelming portion of total overseas construction contract values, and this growth is expected to continue for the next decade. However, contract scopes awarded to the Korean construction firms mainly involve detailed design and construction phases due to their competitiveness for the construction techniques. In other words, front-end-engineering-design and construction project management are not considered part of core business due to the lack of project management skills and experience. The researchers focused on development of construction sequence model required to improve construction planning and scheduling skills for the Korean construction firms. The model identifies critical work items and the sequence throughout project execution process. In addition, the researchers developed a risk evaluation method by applying fuzzy theory to the critical construction activities for the industrial plant construction projects. Developed methodology will help project practitioners to develop project schedule in a timely and effe ctive manner and evaluate project risks associated with scheduling process for the industrial plant construction projects.

A Comparative Study on Power System Harmonics for Offshore Plants (해양플랜트 전력시스템의 고조파 비교분석에 관한 연구)

  • Kim, Deok-Ki;Lee, Won-Ju;Kim, Jong-Su
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.7
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    • pp.900-905
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    • 2016
  • The field of power system harmonics has been receiving a great deal of attention recently. This is primarily due to the fact that non-linear (or harmonic-producing) loads comprise an ever-increasing portion of what is handled at a typical industrial plant. The incidence rate of harmonic-related problems is low, but awareness of harmonic issues can still help increase offshore power plant system reliability. On the rare occasion that harmonics become a problem, this is either due to the magnitude of harmonics produced or power system resonance. This harmonic study used an electrical configuration for the offloading scenario of a Floating LNG (FLNG) unit, considering power load. This electrical network configuration is visible in the electrical network load flow study part of the project. This study has been carried out to evaluate the performance of an electric power system, focusing on the harmonic efficiency of an electrically driven motor system to ensure offshore plant safety. In addition, the design part of this study analyzed the electric power system of an FLNG unit to improve the safety of operation and maintenance.

Imaging Performance Analysis of an EO/IR Dual Band Airborne Camera

  • Lee, Jun-Ho;Jung, Yong-Suk;Ryoo, Seung-Yeol;Kim, Young-Ju;Park, Byong-Ug;Kim, Hyun-Jung;Youn, Sung-Kie;Park, Kwang-Woo;Lee, Haeng-Bok
    • Journal of the Optical Society of Korea
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    • v.15 no.2
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    • pp.174-181
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    • 2011
  • An airborne sensor is developed for remote sensing on an aerial vehicle (UV). The sensor is an optical payload for an eletro-optical/infrared (EO/IR) dual band camera that combines visible and IR imaging capabilities in a compact and lightweight package. It adopts a Ritchey-Chr$\'{e}$tien telescope for the common front end optics with several relay optics that divide and deliver EO and IR bands to a charge-coupled-device (CCD) and an IR detector, respectively. The EO/IR camera for dual bands is mounted on a two-axis gimbal that provides stabilized imaging and precision pointing in both the along and cross-track directions. We first investigate the mechanical deformations, displacements and stress of the EO/IR camera through finite element analysis (FEA) for five cases: three gravitational effects and two thermal conditions. For investigating gravitational effects, one gravitational acceleration (1 g) is given along each of the +x, +y and +z directions. The two thermal conditions are the overall temperature change to $30^{\circ}C$ from $20^{\circ}C$ and the temperature gradient across the primary mirror pupil from $-5^{\circ}C$ to $+5^{\circ}C$. Optical performance, represented by the modulation transfer function (MTF), is then predicted by integrating the FEA results into optics design/analysis software. This analysis shows the IR channel can sustain imaging performance as good as designed, i.e., MTF 38% at 13 line-pairs-per-mm (lpm), with refocus capability. Similarly, the EO channel can keep the designed performance (MTF 73% at 27.3 lpm) except in the case of the overall temperature change, in which the EO channel experiences slight performance degradation (MTF 16% drop) for $20^{\circ}C$ overall temperate change.