• Current Industrial and Technological Trends in Aerospace
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• v.6 no.1
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• pp.56-64
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• 2008

Although the EGSE (Electrical Ground Support Equipment) and MCS (Mission Control System) have many similar or even identical functions, the EGSE used for assembly, integration and validation phase and the MCS for the mission operations phase are normally developed separately and used by different groups of engineers. However, the common ground system for EGSE and MCS has developed and many space missions such as PROBA (PRoject for On-Board Autonomy), ROSETTA, MARS EXPRESS, CRYOSAT (Cryosphere Satellite), GOCE (Gravity field and steady state Ocean Circulation Explorer), and GALILEO have used or will use it to minimize risk, reduce cost and improve overall product quality. It is based on ECSS (European Cooperation for Space Standards) E70 which is the international standard for ground systems and operations published by ECSS E70 Working Group. The ECSS E70 contains the basic rules, principles and requirements applied to the engineering of the ground systems and the execution of mission operations. This paper introduces standardization policy, organization and standard documentation in ECSS. The overview of ECSS E70 such as status, purpose and contents is also described in this paper.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.151-154
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• 2005

With the aim of global environmental monitoring we carried out GPR (Ground Penetrating Radar) surveys at the Livingstion Island in Antarctica. Research area is near the Mt. Charra (340m) in Livingston Island which is located 80 km to the southwest of the King Sejong Station. We have collected 5 lines of GPR data. Two kinds of survey, CMP (Common Midpoint) surveys and common offset profiles, were performed. We classified the glacier into the three layers using electromagnetic velocity of the ice and reflection characteristic, The depth of glacier reached about $80{\~}110\;m$. Some reflectors showed the evidence of the water filled englacial drainage and volcanic ash-layers.

• Journal of the Korean Geophysical Society
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• v.8 no.2
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• pp.63-66
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• 2005

With the aim of global environmental monitoring we carried out GPR (Ground Penetrating Radar) surveys at the Livingstion Island in Antarctica. Research area is near the Mt. Charra (340 m) in Livingston Island which is located 80 km to the southwest of the King Sejong Station. We have collected 5 lines of GPR data. Two kinds of survey, CMP (Common Midpoint) surveys and common offset profiles, were performed. We classified the glacier into the three layers using electromagnetic velocity of the ice and reflection characteristic. The depth of glacier reached about 80∼110 m. Some reflectors showed the evidence of the water filled englacial drainage and volcanic ash-layers.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.191-197
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• 2008

This paper describes the effect of transient state in underground transmission and distribution lines installed together in the same tunnel. Two systems installed in the same tunnel are operated by the common grounding. This paper analyzed that how much one of the two kinds of systems influences the other systems during the transient state by EMTP/ATPDraw. Single line-to-ground fault and lightning surge were selected in transient state condition. These cases were simulated variously according to the variation of common grounding magnitude, fault location and lightning surge magnitude. It is evaluated that the analyzed results will be used for establishment and operating materials of common grounding in the same tunnel.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.894-900
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• 2018

Among the soft ground improvement methods, PBD is the most common construction method because it is cheap and construction is fast. However, if the ground is rigid, additional work is required. In this study, the structural safety, natural vibration, and safety angle of the steel vertical tower structure were evaluated in the development of the PBD composite perforator which can be combined with drilling work and PBD construction. Structural safety was assessed when the wind load of 20 m/s was simultaneously applied to the PBD construction load of 20 tons, the perforating operation of 25 tons, and the wind speed of 50 m/s was applied only to the wind load. The natural frequencies were evaluated up to the sixth mode, and the safety angle was evaluated for static and dynamic safety angles.

• Archives of Plastic Surgery
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• v.45 no.6
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• pp.557-563
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• 2018

Background Numerous Dupuytren's fasciectomy techniques have been described, each associated with unique surgical challenges, complications and recurrence rates. We describe a common ground surgical approach to Dupuytren's disease; 3-dimensional fasciectomy (3DF). 3DF aims to address the potential contributors to the high recurrence rate of Dupuytren's disease and unite current limited fasciectomy practice that varies considerably between surgeons. Methods We describe the 3DF principles; raising thin skin flaps (addressing dermal involvement), excising diseased palmar fascia with a 3-5 mm clearance margin (treating highly locally recurrent conditions) and excising the vertical septae of Legueu and Juvara (providing deep clearance, hence addressing all potentially involved pathological tissue). The surgical outcomes between traditional limited fasciectomy (LF) and 3DF are compared. Results From the 786 operations included (n=585), postoperative recurrence rates were significantly lower for the 3DF group (2/145, 1.4%) than the LF group (72/641, 11.2%) (P= 0.001), and the time to recurrence was significantly longer ($5.0{\pm}0years$ vs. $4.0{\pm}0.2years$; P<0.0001). With recurrence excluded, there were no differences between the postoperative complication rates for 3DF (5/145, 3.5%) and LF (41/641, 6.4%) (P=0.4). Conclusions Our results suggest that 3DF leads to lower recurrence rates and a longer disease-free period for patients, without increasing complications. 3DF provides a safe, efficacious, common ground surgical approach in the treatment of Dupuytren's flexion deformity.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.82-92
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• 2012

This study proposed a new non-destructive evaluation method for concrete bridge deck deterioration using ground penetrating radar (GPR). To calculate dielectric constant of the concrete bridge deck, an extended common mid-point (XCMP) method was developed for a two-layered structure using an air-coupled GPR antenna setup. The deterioration conditions of the concrete bridge deck such as deterioration depth was evaluated based on the dielectric constant and surface-to-average dielectric constant ratio of the concrete bridge deck. A GPR field test was conducted on an old concrete bridge with asphalt concrete surfacing to validate the new evaluation method. The test results showed that the newly proposed method estimated pavement thickness and deterioration depth of the concrete deck in a reasonable level.

• Journal of the Korean Geophysical Society
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• v.6 no.2
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• pp.99-105
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• 2003

Rayleigh waves which has more than 70% of the total seismic energy is the principal component of ground roll. Frequency component of a surface wave has a different propagation velocity, that is, phase velocity, which results in a different wavelength called dispersion. Rayleigh wave is one of the most common ways to use the dispersive properties of surface waves. MASW is a seismic method to evaluate shear-wave velocity information of the ground.

• Journal of the Korean Institute of Landscape Architecture
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• v.19 no.3
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• pp.1-15
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• 1991

The current status of evergreen ground-cover plants as of in the winter months in 50 places selected at random in Seoul was assessed to see how they are at the present, and the following matters of evergreen ground-cover plants were observed to be common aspect of them today during the year of 1989 and 1990 and in winter of Seoul. 1. Ground-cover area in 50 different places of Seoul was 36% of the green area, and the evergreen ground-cover area was 3% of total ground-cover area. As the result, most of ground cover plants founded to be zoysia grasses. 2. Total number of evergreen ground-cover plants species was 24, and the species most frequently found were Juniperus chinensis and horizontalis, Buxus koreana, Liriope platyphylla var. nana. Taxus cuspidats, Rhododendron lateritium, Pleioblastus pygmaea, Poa pratensis in that order of the number of plasces assessed, and sere Poa pratensis, Agrostis tennuis, Liriope platyphylla, Buxus koreana, Juniperus chinensis and horizontalis, Taxus cuspidata. var. nana, Rhododendron lateritium in the order of area planted. 3. Woody plants included 9 species and occupied 16% in the area, also introduced plants included 14 species and occupied 79% in the area. As introduced evergreen grasses occupied, almost of evergreen ground-cover herbs, planting of evergreen ground-cover herbs and native plants are thought to be desirable. 4. Flowering plants of 16 species were found to be 16% of the total evergreen ground-cover area. 5. The ratio of topographical difference, such as plain versus slope for planting site, was 82 and 18% respectively, and sunny versus shady and intermediate places were 72, 15 and 13% respectively. 6. Although appearance of plants was generally fair, poor and drying plants were assessed 33% for the number of places planted, and 11% for the area. It seems to be necessary to manage those plants to their growth characteristics, and desiable to introduce various plant species adaptable to the winter climate of Seoul and grow for the winter landscaping purpose. 7. The poor use and lack of evergreen ground-cover plants are regarded to be deficient in the valus and reconization of them, particularly in the landscaping works. It is therefore considered important to bring out pertinent measures against these inadequate situations.

• KIEAE Journal
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• v.8 no.1
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• pp.71-79
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• 2008

Lower birth rate and higher elder people are serious social problem in Korea. In 2003, the total birth rate is 1.19 per person, that record is lowest among OECD country. In 2005, Korea has been the aging society with 9.0% in aged population rate. Increasing of aged population results in elder estrangement and confliction with other generations. The social problem can be solved in some degree by improving housing environment and many kinds of welfare program. This study suggests a solution of the problem by applying community space located on ground level floor. The ground level floor of apartment has many physical benefits like connection to the earth, extension, safeness for the aged and child. in case of the National Rental apartment, small residential area and high rate of elder, child, the disabled make the ground level floor useful space for community. According to case study, almost the National Rental apartment hasn't enough facilities supporting various generations and don't supply comfortable environment. So, this study presents how to design the National Rental Apartment's community space located on ground level floor.