• 한국전자거래학회지
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• 제2권1호
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• pp.53-77
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• 1997

This paper presents an efficient methodology for information system development by adopting the concept of extended components which can achieve the improvement of development productivity, reductrion of development time periods, quality improvement of information systems, etc. when information development projects are carried out. First of all, for efficient development of information systems, development steps of current methodologies for information system analysis are subdivided into components in detail and outputs required at each step are defined. The components are extended by types and various application methods are proposed in each step of information system development. In addition, a method which uses advantages of current methods such as SDLC, prototyping, and RAD, is also proposed. In this research, a CASE tool named S-Designer is used for the development of extended components and their interface, and a system development method called DSDM for the deviation of detailed steps and corresponding outputs.

• 생물환경조절학회지
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• 제20권2호
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• pp.83-92
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• 2011

본 연구는 주간에 온실 내에서 환기로 인하여 배출되는 잉여 태양에너지를 축열할 적정 축열 시스템 설계의 기초자료를 제공할 목적으로 확보한 표준기상년(TMY; Typical Meteorological Year) 데이터를 이용하여 주요 온실 형태별로 잉여 태양에너지를 분석하였다. 그 연구결과를 요약하면 다음과 같다. 07-자동화-1형 및 08-자동화-1형의 경우, 온실형태에 관계없이 매우 유사한 열수지 경향을 보였다. 즉, 잉여 태양에너지가 차지하는 비율은 온실 형태별로 각각 약 20.0~29.0% 및 20.0~29.0% 정도로 나타났다. 그리고 소요 난방에너지를 온실 형태별로 각각 약 54.0~225.0% 및 53.0~218.0% 정도 보충할 수 있을 것으로 나타났다. 07-단동-1형과 07-단동-3형의 경우도 온실형태에 관계없이 매우 유사한 열수지 경향을 보였다. 즉, 잉여태양에너지가 차지하는 비율은 온실 형태별로 각각 약 20.0~26.0% 및 21.0~27.0% 정도로 나타났다. 그리고 소요 난방에너지를 온실 형태별로 각각 약 57.0~211.0% 및 62.0~228.0% 정도 보충할 수 있는 량이다. 그리고 온실형태에 관계없이 대관령 및 수원지역을 제외하면 나머지 지역은 잉여 태양에너지만으로도 난방에너지를 충당할 수 있음을 알 수 있었다.

• 유기물자원화
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• 제16권4호
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• pp.43-49
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• 2008

본 연구의 목적은 석유화학에너지를 대체하기 위해 바이오가스 생산을 위한 돈분 및 음식물쓰레기 혼용 혐기소화 시 황화수소가스 농도 및 발생비율을 모니터링 한 것이었다. 바이오가스 생산을 위한 혼합혐기 소화는 휘발성 고형물 2%기준 다양한 돈분 및 음식물쓰레기 혼합비율하에서 시럼병을 이용하여 수행하였다. 황화수소가스 발생비율은 처리별 소화기간에 따라 다양하다 할지라도, 수급원료를 돈분만을 이용한 경우는 음식물 쓰레기와 비교할 때 황화수소 발생량은 2.4배 낮게 나타난 것으로 관측되었다. 돈분과 음식물쓰레기 혼합비율에 따른 황화수소가스 농도에 미치는 영향에 대해서는 음식물쓰레기 혼합비율이 높으면 높을수록 황화수소 농도가 높게 나타났다. 황화수소가스 평균 농도는 돈분처리, 0.1452% 에서부터 음식물쓰레기 처리, 0.3420% 까지 다양 하였다. 돈분 및 음식물쓰레기 혼용 혐기발효 시 바이오가스 조성비율은 메탄가스가 53.2%, 이산화탄소 23.9%, 황화수소 0.3% 및 수분을 포함한 기타 22.7%로 이루어져 있는 것으로 나타났다.

• Journal of Radiation Protection and Research
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• 제10권2호
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• pp.137-143
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• 1985

방사선(放射線)을 조사(照射)할 때의 생쥐의 연령(年齡)과 방사선(放射線) 조사후(照射後) 시문경과(時問經過)에 따른 염색체이상(染色體異常) 빈도(頻度)와의 상호관계를 밝히기 위하여 40, 150, 300일(日)된 생쥐에 200 rad의 ${\gamma}$선(線)을 전신일시(全身一時) 조사(照射)하여 1, 2, 4, 8, 16, 30, 60, 90일(日) 이 경과(經過)한 8개(個)의 실험군(實驗群)을 대상으로 골수세포(骨髓細胞)의 염색체(染色體)를 관찰하여 다음과 같은 결과(結果)를 얻었다. 8개(個)의 실험군(實驗群)에 있어서 염색체이상(染色體異常)을 가진 세포(細胞)의 빈도(頻度)는 40일(日)된 생쥐에서는 53.0%, 21.5%, 8.4%, 8.4%, 12.0%, 8.0%, 7.0%, 5.0%였고 150일(日)된 생쥐에서는 32.5%, 12.1%, 10.5%, 12.8%, 0.03%, 9.7%, 7.0%, 4.2%였으며 그러고 300일(日)된 생쥐인 경우는 27.7%, 13.6%, 9.0%, 9.3%, 13.3%, 14.4%, 7.5%, 9.5%였다. 방사선(放射線) 조사후(照射後) 2일(日) 이내에서는 늙은 쥐보다 어린 쥐에서 염색체이상(染色體異常)의 빈도(頻度)가 높았고 방사선(放射線) 조사후(照射後) 4일(日) 이후에는 반대로 어린쥐보다 늙은 쥐에서 염색체이상(染色體異常)의 빈도(頻度)가 높은 경향이 있었다.

• The Korean Journal of Pain
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• 제26권2호
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• pp.148-153
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• 2013

Background: C-arm fluoroscope has been widely used to promote more effective pain management; however, unwanted radiation exposure for operators is inevitable. We prospectively investigated the differences in radiation exposure related to collimation in Medial Branch Block (MBB). Methods: This study was a randomized controlled trial of 62 MBBs at L3, 4 and 5. After the patient was laid in the prone position on the operating table, MBB was conducted and only AP projections of the fluoroscope were used. Based on a concealed random number table, MBB was performed with (collimation group) and without (control group) collimation. The data on the patient's age, height, gender, laterality (right/left), radiation absorbed dose (RAD), exposure time, distance from the center of the field to the operator, and effective dose (ED) at the side of the table and at the operator's chest were collected. The brightness of the fluoroscopic image was evaluated with histogram in Photoshop. Results: There were no significant differences in age, height, weight, male to female ratio, laterality, time, distance and brightness of fluoroscopic image. The area of the fluoroscopic image with collimation was 67% of the conventional image. The RAD ($29.9{\pm}13.0$, P = 0.001) and the ED at the left chest of the operators ($0.53{\pm}0.71$, P = 0.042) and beside the table ($5.69{\pm}4.6$, P = 0.025) in collimation group were lower than that of the control group ($44.6{\pm}19.0$, $0.97{\pm}0.92$, and $9.53{\pm}8.16$), resepectively. Conclusions: Collimation reduced radiation exposure and maintained the image quality. Therefore, the proper use of collimation will be beneficial to both patients and operators.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.640-644
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• 1998

AT cells exhibit defective cell cycle regulation following DNA damage. Previous studies have shown that induction of p53 and p2i proteins are delayed in response to ionizing rad iation, resulting in the failure of G1/S checkpoint in AT cells. In this study, further investigation of the molecular mechanisms underlying G1/S phase progression in AT cells was conducted. Exponentially growing normal and AT cells were exposed to 2 Gly of ionizing radiation and the expression levels and functional activities of Rb and E2F-1 proteins were determined. We observed overexpression of hyperphosphorylated Rb and E2F-1 proteins in AT cells, which was unaffected post-irradiation. Furthermore, gel shift assays showed that E2F-1-DNA binding was constitutive in AT cells, whereas it was inhibited in control cells following exposure to ionizing radiation. The data suggests that abnormalities in the function of Rb and E2F-1 proteins may also be responsible for the failure of AT cells to arrest in the G1/S checkpoint in response to DNA damage.

• Journal of Astronomy and Space Sciences
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• 제37권3호
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• pp.171-185
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• 2020

This paper presents a methodology for Initial Orbit Determination (IOD) based on a modification of the Laplace's geocentric method. The orbital elements for Near-Earth asteroids (1864) Daedalus, 2003 GW, 2019 JA8, a Hungaria-type asteroid (4690) Strasbourg, and the asteroids of the Main Belt (1738) Oosterhoff, (2717) Tellervo, (1568) Aisleen and (2235) Vittore were calculated. Input data observations from the Minor Planet Center MPC database and Astronomical Observatory of the Technological University of Pereira (OAUTP; MPC code W63) were used. These observations cover observation arcs of less than 22 days. The orbital errors, in terms of shape and orientation for the estimated orbits of the asteroids, were calculated. The shape error was less than 53 × 10^-3 AU, except for the asteroid 2019 JA8. On the other hand, errors in orientation were less than 0.1 rad, except for (4690) Strasbourg. Additionally, we estimated ephemerides for all bodies for up to two months. When compared with actual ephemerides, the errors found allowed us to conclude that these bodies can be recovered in a field of vision of 95' × 72' (OAUTP field). This shows that Laplace's method, though simple, may still be useful in the IOD study, especially for observatories that initiate programs of minor bodies observation.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2177-2185
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• 2015

Breast cancer is the most common malignancy in women around the world. About one in 12 women in the West develop breast cancer at some point in life. It is estimated that 5%-10% of all breast cancer cases in women are linked to hereditary susceptibility due to mutations in autosomal dominant genes. The two key players associated with high breast cancer risk are mutations in BRCA 1 and BRCA 2. Another highly important mutation can occur in TP53 resulting in a triple negative breast cancer. However, the great majority of breast cancer cases are not related to a mutated gene of high penetrance, but to genes of low penetrance such as CHEK2, CDH1, NBS1, RAD50, BRIP1 and PALB2, which are frequently mutated in the general population. In this review, we discuss the entire spectrum of mutations which are associated with breast cancer.

• 한국주조공학회지
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• 제10권6호
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• pp.528-537
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• 1990

7XXX aluminum alloy powders produced by the self-manufactured rotating disc atomizer were investigated to determine the influence of the atomization parameters on the particle size distributions in air atmosphere. The particle size distributions are almost always bimodal with the dominant mode on the large particle size. Average powder size of 7XXX aluminum alloy is $74/{\mu}m~125/{\mu}m$ when melt is poured with the rate of 9g /sec at 730$^{\circ}C$ on a rotating disc of 30㎜ diameter at 6300rad/sec. The mass of finer particle increased when disc diameter, angular velocity, pouring temperature increased and pouring rate decreased. The powder shapes of bimodal change from acicular to tear-drop and from tear-drop to ligament with increasing powder size. Powder shape was determined by the atomization mechanism and oxidation in liquid state. Microstructure of powders appeared to be cell and cellular dendrite. The SDAS of Al-7.9wt%Zn-2.4wt%Mg-1.5wt%Cu-0.9wt%Ni Powders is $0.8{\mu}m~1.0{\mu}m$ for the powders of $size＋44{\mu}m~53{\mu}m$ and $1.6{\mu}m∼1.8{\mu}m$ for the powders of $size＋105{\mu}m~125{\mu}m$, repectively.

• Steel and Composite Structures
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• 제12권1호
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• pp.53-72
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• 2012

In this study, the physically-based failure models for matrix and fibers in compression and tension loading are introduced. For the 3D stress based fiber kinking model a modification is proposed for calculation of the fiber misalignment angle. All of these models are implemented into the finite element code by using the advantage of damage variable and the numerical results are discussed. To investigate the matrix failure model, purely in-plane transverse compression experiments are carried out on the specimens made by Glass/Epoxy to obtain the fracture surface angle and then a comparison is made with the calculated numerical results. Furthermore, shear failure of $({\pm}45)_s$ model is investigated and the obtained numerical results are discussed and compared with available experimental results. Some experiments are also carried out on the woven laminated composites to investigate the fracture pattern in the matrix failure mode and shown that the presented matrix failure model can be used for the woven composites. Finally, the obtained numerical results for stress based fiber kinking model and improved ones (strain based model) are discussed and compared with each other and with the available results. The results show that these models can predict the kink band angle approximately.