• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.55-60
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• 1990

The objective of this study is to predict the nonlinear behavior of reinforced concrete shear walls, with the reinforcement uniformly distributed, under reversed cyclic loads. This study introduces joint Element Model which formulates the pulling out of rebars, slipping and intrusion of junction planes. The applicability of this study was experimental verfied by specimens SW1, SW2 and SW3 tested by authors, Wall1 by Paulay, SW16 and SW19 by Sheu. In almost specimen, the ratio of analytical to experimental maximum shear stress is within approximately 5%. In case of energy dissipation and maximum drift, the analytical results fully coincide with those of experiment.

• Journal of Korean Electronics
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• v.10 no.7
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• pp.77-81
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• 1990

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.285-294
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• 2000

In order to determine the horizontal and vertical distributions of metals and prospect the recent metal pollution history in Nakdong Estuary, we took surface and core sediments. Maximum value of organic matter occurs at the upstream site located 4 km from Nakdong barrage, and the concentration of trace metals (Zn, Cu, and Pb etc.) decrease seaward in the estuary. The sedimentation rates, based on $^{210}$Pb$_{ex}$ and $^{137}$Cs activities, were 0.34 cm/yr in inside of barrage (core 1) and 0.25 cm/yr in Changrim (core 4). Sediment mixing layer does not exist in core 1, where anoxic condition is known to be prevail. The topmost sediment layer of core 4 (<3.5 cm) is severely mixed. At sites 1 and 4, concentrations of Cu slowly increased during the period of 1920-1970, rapidly increased during 1970-1990, and followed by slight decrease after 1990. Zn contents increased in early 1960s and peaked in 1993, and followed by decrease after 1990s. Pb has increased continuously since early 1970s. At the downstream of the barrage, Cu and Zn have increased in the topmost layer. The trend of increase of Cu is evident after 1950 (11 cm in sediment depth). Overall trend of heavy metal concentration clearly indicates the pollution has been increasing after the construction of the barrage.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.437-442
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• 2015

Aim: To establish a pancreatic cancer stem cell model using human pancreatic cancer cells in nude mice to provide a platform for pancreatic cancer stem cell research. Materials and Methods: To establish pancreatic cancer xenografts using human pancreatic cancer cell line SW1990, nude mice were randomly divided into control and gemcitabine groups. When the tumor grew to a volume of $125mm^3$, they treated with gemcitabine at a dose of 50mg/kg by intraperitoneal injection of 0.2ml in the gemcitabine group, while the mice in control group were treated with the same volume of normal saline. Gemcitabine was given 2 times a week for 3 times. When the model was established, the proliferation of pancreatic cancer stem cells was observed by clone formation assay, and the protein and/or mRNA expression of pancreatic stem cell surface markers including CD24, CD44, CD133, ALDH, transcription factors containing Oct-4, Sox-2, Nanog and Gli, the key nuclear transcription factor in Sonic Hedgehog signaling pathway was detected by Western blot and/or RT-PCR to verify the reliability of this model. Results: This model is feasible and safe. During the establishment, no mice died and the weight of nude mice maintained above 16.5g. The clone forming ability in gemcitabine group was stronger than that of the control group (p<0.01). In gemcitabine group, the protein expression of pancreatic cancer stem cell surface markers including CD44, and ALDH was up-regulated, the protein and mRNA expression of nuclear transcription factor including Oct-4, Sox-2 and Nanog was also significantly increased (P<0.01). In addition, the protein expression of key nuclear transcription factor in Sonic Hedgehog signaling pathway, Gli-1, was significantly enhanced (p<0.01). Conclusions: The pancreatic cancer stem cell model was successfully established using human pancreatic cancer cell line SW1990 in nude mice. Gemcitabine could enrich pancreatic cancer stem cells, simultaneously accompanied by the activation of Sonic Hedgehog signaling pathway.

• Journal of the Korean Society of Systems Engineering
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• v.6 no.2
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• pp.47-57
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• 2010

Taylor and Ford in the 1910s led to the "scientific management" for the entire industry from the manufacturing spread of TQM Total Quality Management has been structured as a management efficiency, such as 6-Sigma techniques were developed. SW development also introduces the idea, such as CMMI and SPICE-based process management, management practices have evolved. However, in recent years to increase the knowledge of workers in the manufacturing process oriented management approach is under serious challenge. Business performance or productivity will be varied depending all motivation, human relationship, job involvement rather than simply putting a lot of time. Especially in the SW industry which is depending on human resource, Creativity should be limited in traditional management methods. Recently, Google and Apple, Cisco and global advanced companies adopt a human relationship management. Their productivity and creativity in product development has been successful by giving autonomy and motivation, enthusiasm and vision to tile employees. Human relationship management since the mid-1990s, appears as a new paradigm so called Agile process in the field of SW development. Agile processes emphasis on light, flexible and responding to changes immediately in the business environment step away from traditional management approach which is the heavy and complicated process. In this paper, agile project management concepts and practices which is applied to industry will be examined.

• The Korean Journal of Malacology
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• v.13 no.2
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• pp.185-192
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• 1997

1990젼 3월부터 1991년 2월까지 전라북도 군산시 내초도 연안에 서식하는 동죽의 성장을 조사하였다. 1.조사해역의 연간 수온분포는 2.0-26.3$^{\circ}C$이고, 간석지 온도는 0.7-36.2$^{\circ}C$이었다. 2. 동죽의 패각에 나타나는 윤문은 연 1회 형성되며 윤문 형성시기는 3-4월로 조사되었다. 3. 초륜 형성기간은 9개월(0.75년)로 나타났다. 4. 각장(SL: mm)과 체중(TW: G)간의 관계는 TW=1.090 x $10^{-4}$ S $L^{3.2798}$( $r^{2}$=0.99)이었으며, 각장과 각고(SH:mm)간의 관계는 SH=0.865 SL + 0.250( $r^{2}$=0.99)이고, 각장과 각폭(SW: mm) 간의 관계는 SW=0.599 SL - 0.203 ( $r^{2}$=0.98; 각장 22 mm미만), SW=0.724 SL - 2.796( $r^{2}$=0.91; 각장 22 mm이상)이었다.5. 연령(t)에 대한 각장(S $L_{t}$ )의 Bertalanffy성장식은 $L_{t}$ =51.399(1- $e^{0.585}$8(t+0.064)이고, 연령(t)에 대한 체중 (T $W_{t}$ )의 Bertalanffy성장식은 $W_{t}$ =44.467(1- $e^{0.585}$8(t+0.064)$^{3}$로 나타났다.타났다.

• Informatization Policy
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• v.17 no.1
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• pp.63-77
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• 2010

This paper investigates the impact of the government R&D expenditure on the IT industry in Korea. The analysis of such impact can be used to derive the policy implications for the IT industry. The contribution of government R&D to the IT industry was analyzed based on the input-output table of the year 1990-1995-2000. The results show that the amount of the government R&D expenditure induced the IT industry to book twice greater production than it would have been in the absence of such government R&D expenditure during the period under investigation. It is also shown that job creation was strongly encouraged in the broadcasting equipment, software and computer-related services. During the period under the study, the composition of the workers in the IT hardware industry remained unchanged while the production increased significantly, which confirms the jobless growth in the IT hardware industry. The results of this study suggest that the government R&D should focus on improving the competitiveness of the intermediate good and parts industry.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.3
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• pp.200-206
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• 1993

Since November 1990, observations of carbon monoxide(CO) levels have been carried out at Tat-ahn Peninsula(TAP) in Korea. Analysis on atmospheric data, obtained in the period from November 1990 to February 1992, is carried out and the results are included in this study. It is observed that variations of monthly average level on CO are in the range of 141.61-516.06ppb(amplitude 374.45 ppb). An average level in 1991 is 308.18 ppb. CO observed at TAP has a larger seasonal variation. One of reasons appears that CO of TAP is strongly influenced by local sources and westerly airflows. When this gas of TAP is compared with data observed at Korea National University of Education(KNU) and in Seoul, we learn that CO values of KNU are higher(in average 2.15 times) than those of TAP; CO value observed in Seoul are 7 times higher than those of TAP. We interprete that air samples taken both at KNU and in Seoul are influenced strongly by local sources than those at TAP. According to analysis of trajectories and air flows, the CO value is higher with NW airflows than the value with SW airflows.

• Journal of the Korean earth science society
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• v.23 no.8
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• pp.683-696
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• 2002

In this work. we investigated the ozone data sets that exceeded ambient air quality standards from 31 air quality monitoring stations dispersed across the Seoul metropolitan city during the period covering 1990 and 2000. To specifically describe spatial dependency of high level O$_3$ occurrence, we grouped our data into four different geographical ozone exceedance is much longer in SW than the other three sectors. When we compared the exceedance data in terms of occurrence frequency, the month of maximum frequency differed slightly among different sectors. Examination of long-term exceedance trend indicated that its frequency increased continuously from all sectors over the past years, although slightly opposite patterns existed in their absolute values. Most importantly, its peak occurrence frequency seemed to center in very recent years such as 1998 (NE sector) and 2000 (ail pattern sectors except NE). Consequently, we were able to describe the existence of certain patterns of ozone exceedance data sets in terms of both temporal and spatial scales.

• Explosives and Blasting
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• v.8 no.3
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• pp.3-13
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• 1990

First ot of all, under given condition such as bit gage of 36mm Drill bit with right class of jack-leg-experimental test carried out from two face of Bench, firing of each hole brought 90 degree Angle face and them measured length of Burden and charged ammount of powder as following. $ca=\frac{A}{SW}$ A=Activated Area A=nd i=m S=Peripheral length of charged, room Ca=Rock Coeffiecency d: di=Hole diameter When constructed subway of Seoul in 1980 the blasting works increased complaint of ground vibration, in order to prevent the damage to structures. Some empirical equations were made as follows on condition with Jackleg Drill (Bit Gage 36mm) and within 30 meter distance between blasting site and structures. $V=K(D/W)^{-n}$ N=1.60 - 1.78 K= 48 - 138 Project is one of contineous works to above a determination of empirical equation on the cautious blasting vibration with Crawler Drill (70-75mm) in long distance. $V=41(D/\sqrt[3]{W})^{-1.41}$ $30m\le{D}\le{100m}$ $V=124(D/\sqrt[3]{W})^{-1.66}$ $100m\le{D}\le{285m}$.