• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.5
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• pp.615-622
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• 2000

Numerical simulation is performed with Denton's code to get pressure loss coefficients in wide range of reverse flow incidence(from -90 degree to +85 degree) for an axial compressor cascade. As a results, it is found that the pressure loss coefficient is increased with incidence and there exist critical incidence which corresponds to the maximum pressure loss coefficient. Pressure loss coefficient with bigger incidence than its critical value is decreased. The effect of increasing incidence in a cascade extremely reduce the mass flow rate by the large flow separation region. Consequently this effect reduce the portion of dynamic pressure in the total pressure loss and beyond the critical incidence the pressure loss coefficient decrease.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.3
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• pp.261-265
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• 2022

In this paper, comparative studies between Linde, Claude and advanced cycle for the liquefaction of nitrogen have been completed. PRO/II with PROVISION release 2021. 1 from AVEVA company (Cambridge, UK) was used, and Peng-Robinson equation of the state model with Twu's alpha function was selected for the modeling of the condensation of nitrogen. When using Claude liquefaction, we can reduce the total compression power by 49.25% for the comparison of Linde cycle. And finally, we could conclude that 90.41% of total compression power was saved when using an advanced cycle being compared to Linde liquefaction cycle.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.4
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• pp.446-450
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• 2022

In this paper, comparative studies between Linde-Hampson and Claude cycle for the liquefaction of oxygen have been completed. PRO/II with PROVISION release 2021. 1 from AVEVA company (Cambridge, UK) was used, and Peng-Robinson equation of the state model with Twu's alpha function was selected for the modeling of the condensation of oxygen. When using Claude liquefaction cycle, we could reduce the total compression power by 59.51% for the comparison of Linde-Hampson cycle.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.191-196
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• 1993

Since the welding process is complex and highly nonlinear, it is very difficult to accurately model the process for real-time control. In this paper, a discrete-time transfer function matrix model for gas metal arc welding process is proposed. Although this linearized model is valid only around the operating point of interest, the adaptation mechanism employed in the control system render this model useful over a wide operating range. A multivariable one-step-ahead adaptive control strategy combined with a recursive least-squares method for on-line parameter estimation is implemented in order to achieve the desired weld bead geometries. Command following and disturbance rejection properties of the adaptive control system for both SISO and MIMO cases are investigated by simulation and experiment.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.2
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• pp.3-9
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• 2012

The paper describes a novel technique for on line parameter identification of three-phase induction motors from a single, run up to speed test. Data is sampled during this test with the normal locked rotor and synchronous speed data captured on the way to reaching the motor's rated speed. Rotor parameter variations with frequency due to skin and proximity effects and other non-linear imperfections such as heating and main flux path saturation are taken into account. This method is ideal for determining and/or verifying parameters used in high performance drives.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.298-299
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• 2000

3차원 영상을 디스플레이하기 위한 반사형 광기록식 공간 광소자(Optically Addressed Spatial Light Modulator)를 연구하였다. 다시점 영상으로 표현되는 3차원 영상을 시분할 방식으로 디스플레이 하기 위해서는 고속의 프레임 구동이 가능한 디스플레이 소자가 있어야 하는데 본 연구에서는 Surface Stabilized Ferroelectric Liquid Crystal을 이용하여 그림 1과 같은 구조를 갖는 소자를 제작하였다.$^{(1)}$ 입력상이 입사되는 방향에 1.1 미리 미터 정도의 ITO 유리 기판이 있으며 투명 전극 다음에 약 2마이크론 정도의 비결정질 구조를 갖는 Si:H 감광층이 있다. 반사형 구조를 위해서 반사경으로 알루미늄 층을 10마이크론 X 10 마이크론 크기의 미소 패턴으로 화소화하였으며 강유전성 액정 결정을 Surface Stabilized화하기 위해서 배양막과 2 마이크론 이하의 Spacer를 두었다. 일반적인 액정 소자와 같이 다시 배양막과 유리 기판을 갖게 하였다. (중략)

• The Korean Journal of Zoology
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• v.14 no.1
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• pp.7-18
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• 1971

깔때기거미屬(Coras)은 1898年에 E. Simon이 創設한 이래, 北美洲에서 約 15種, 極東地域에서 다음 3種이 記載되었다. 卽 C. insidiosus(L. Koch, 1877) 日本 C. luctuosus(L. Koch, 1877) 日本 $\\cdot$ 中國(\ulcorner) C.plancyi(Simon, 1880) 日本 $\\cdot$ 中國 本屬은 Coelotes 屬과 매우 닮아서, 그 사이에 뚜렷한 區分을 지우기란 困難하며, 따라서 種의 所屬에도 적지않은 混亂을 招來하고 있다. 本屬은 종래에는 Ageleidae의 Ageleninae에 所屬시켜 왔으나 最近에 Lehtinen(1967)은 이것을 F.O. Pickard-Cambridge(1893)가 設定한 Coelotinae로 옮겼는데 이것은 매우 타당한 處事라 하겠다. 韓國産 Coras 屬에 對해서는 白(1942, 1962, 1967), 白 $\\cdot$ 金(1956) 및 南宮(1964) 等이 日本과 共通種인 Coras insidiosus를 報告한바 있다. 그러나 이번 調査에서 이것은 Coelotes songminjae Paik et Yaginuma, 1969의 synonym으로 밝혀졌으므로 우리 나라의 spider fauna에서 除外하기로 했다. 한편 筆者 所藏의 標本을 整理한 結果 새로히 1韓國未記錄種 과 1新種을 얻었기에 이에 記載하는 바이다. 韓國未記錄種 Coras luctuosus (L. Koch, 1877) 왜깔때기거미 新種 Coras vulgaris n. sp. 한국깔때기거미

• Genomics & Informatics
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• v.5 no.4
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• pp.196-199
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• 2007

BOD is an FTP service management tool on the Internet. It was developed for biological researchers in South Korea. It enables easier and faster access of bioinformation without having to go through foreign FTP sites. BOD includes an automatic downloader with a management and email alert service from which the user can easily select and schedule any biological database. Once listed in BOD, the user can check and modify the download status and data from an additional email alert service.

• Journal of Chest Surgery
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• v.55 no.1
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• pp.77-80
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• 2022

Kartagener syndrome (KS) is a rare disease with an incidence of 1 in 20,000 to 30,000 births. There is no cure for KS, and conservative medical treatments are used to relieve symptoms and prevent disease progression. Lung transplantation (LT) is the only treatment option for end-stage KS. Since patients with KS have anatomical abnormalities such as situs inversus totalis, which often require surgery to correct, most reports are related to surgical techniques. Reports about morphological adaptations and changes in transplanted lung structure after LT in patients with KS are rare. We performed LT in a patient with KS and observed morphological adaptation of the lungs for 6 months on chest computed tomography using a quantitative evaluation tool (Chest Image Platform; Harvard University Disability Resources, Cambridge, MA, USA).

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.40.2-40.2
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• 2014

The connection between the active galactic nuclei (AGNs) and star formation activity is one of the most important issues in understanding the coevolution of supermassive black holes (SMBHs) and galaxies. In our recent study, by using SDSS quasar spectra we found that the emission-line flux rations involving a nitrogen line, i.e., $NV{\lambda}1240$, correlate with the Eddington ratio. This correlation suggests that the mass accretion into SMBH is associated with a post-starburst phase, when AGB stars enrich the interstellar medium with the nitrogen. Moreover, we focused on nitrogen-loud quasars, which have prominent emission lines of the nitrogen, to investigate whether this argument is correct or not. We will present our recent results described above and discuss the relation between the star formation and feeding to SMBHs.