• 한국조경학회지
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• 제28권6호
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• pp.77-83
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• 2001

The purpose of this study is to provide the fundamental material and information for the plant maintenance after rooftop planting through physiochemical characteristics. The characteristics of artificial soils after rooftop planting from 1993 to 1999 was investigated. Fourteen investigation areas were selected from 4 cities(2 areas selected by each year). The analysis of the circumstances of the areas, the physical characteristics, and the chemical characteristics of the soil were conducted. The artificial soil pH ranged 5.26∼7.40 showing that after construction the soil pH tended to decrease. The soil bulk density of the site was lowest in 1999, 0.15g/㎤, and used to increase toward 1993. We found the fact that the soil bulk density increased gradually after rooftop application . The coefficients of permeability of the soils range from 0.016 to 0.052 cm/sec, which seemed to be in good permeability level. The artificial soils had relatively high water moisture capacity of 62.69∼71.36%. The soil organic matter content of the artificial soils ranged from 0.43 to 1.34%. The exchangeable caution concentration in the artificial soil ranged, Na, 2.36∼4.71mg·{TEX}$kg^{-1}${/TEX}, Mg 0.88∼2.84mg·{TEX}$kg^{-1}${/TEX},K 2.97∼9.61 mg·{TEX}$kg^{-1}${/TEX}, and Ca 9.39∼28.23 mg·{TEX}$kg^{-1}${/TEX}. The amount of total N ranged from 0.003 to 0.286% in study sites. Soil chemical properties varied year to year and showed little tend. The research results showed that some characteristics of the artificial soil were changed after rooftop planting, i.e., soil pH and soil bulk density. Soil bulk density had a negative relationship with the coefficient of permeability, showing that the drainage condition might be limited after some period. This study suggests that a diversity of the research in the changes of the plant growth basis on the areas after construction.

• 한국정보과학회논문지:소프트웨어및응용
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• 제35권11호
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• pp.653-660
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• 2008

최근에 제시된 서비스 기반 컴퓨팅 패러다임에서의 서비스 기반 소프트웨어 개발을 지원하기 위한 체계적인 프로세스 모델에 대한 요구가 대두되고 있다. 기존에 제시된 Unified Software Development Process, UML Components 등의 방법론은 컴포넌트에 초점을 두고 만들어진 방법으로, 서비스의 정의, 바인딩, BPEL(Business Process Execution Language)을 이용한 서비스의 조합등과 같은 서비스 기반의 개발이 가지고 있는 특징을 반영하지 못하고 있다. 또한 서비스 기반의 개발 방법론으로 제시된 SOUP(Service Oriented Unified Process), SOMA(Service Oriented Modeling and Architecture) 등은 개념적인 절차가 위주로 되어 있지, 구체적인 가이드라인, 산출물 및 접근 방법을 명확히 제시하지 않는다. 그러므로 본 논문에서는 서비스 기반의 개발 패러다임을 지원하기 위한 체계화되고, 간소화된 프로세스 모델을 제시한다. 또한 OMG에서 제시한 SPEM(Software Process Engineering MetaModel)을 적용하여 프로세스 모델을 명시적으로 표현한다. 본 논문에서 제안된 프로세스 모델을 실제 서비스 기반의 개발에 적용함으로써 서비스 기반 소프트웨어 개발의 체계성 및 효율성을 증대시킬 수 있게 된다.

• 한국조경학회지
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• 제31권4호
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• pp.1-12
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• 2003

The urban park provides a safe rest and leisure area, and offers the beauty of nature to counter the drearyness of urban space. It can provide benefits such as the reduction of environmental pollution, the regulation of the local climate, and it can also provide a safe area during times of disaster. However, there was no interest in urban park development and control in Korea during the economic boom of the mid 1960s. Furthermore, during the industrialization process, the population grew significantly in the cities and the cities' scales were noticeably extended; as a result of this, the living environment and the natural environment in the cities worsened. With rapid urbanization and industrialization, urban green area diminished, and it became necessary to organize the urban park system to improve quality of life. 45% of south korea's population lives in 6 cities, which is only 4% of Korea's land size. The Urban park system has to be considered in the urban planning process. Paris' urban green system can be a role-model for Korea's urban green development plan to function organically. Urban public park concepts have been used in Paris's urban planning since 1850. There were hardly any parks, gardens and squares for the public before the middle of the 19th century. For improving life-styles for the poor, Napoleon III strongly supported the development of green space systems in Paris by G.E. Haussmann. Napoleon III and Haussmann established and applied the urban green regulation within Paris urban planning. The purpose of this study is to investigate the green regulations Haussmann's Paris urban plan and urban green space system: and as a result of this, it can be an indicator for urban green space development in Korea.

• Computers and Concrete
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• 제3권4호
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• pp.213-233
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• 2006

Over the past years techniques for non-linear analysis have been enhanced significantly via improved solution procedures, extended finite element techniques and increased robustness of constitutive models. Nevertheless, problems remain, especially for real world structures of softening materials like concrete. The softening gives negative stiffness and risk of bifurcations due to multiple cracks that compete to survive. Incremental-iterative techniques have difficulties in selecting and handling the local peaks and snap-backs. In this contribution, an alternative method is proposed. The softening diagram of negative slope is replaced by a saw-tooth diagram of positive slopes. The incremental-iterative Newton method is replaced by a series of linear analyses using a special scaling technique with subsequent stiffness/strength reduction per critical element. It is shown that this event-by-event strategy is robust and reliable. First, the model is shown to be objective with respect to mesh refinement. Next, the example of a large-scale dog-bone specimen in direct tension is analyzed using an isotropic version of the saw-tooth model. The model is capable of automatically providing the snap-back response. Subsequently, the saw-tooth model is extended to include anisotropy for fixed crack directions to accommodate both tensile cracking and compression strut action for reinforced concrete. Three different reinforced concrete structures are analyzed, a tension-pull specimen, a slender beam and a slab. In all cases, the model naturally provides the local peaks and snap-backs associated with the subsequent development of primary cracks starting from the rebar. The secant saw-tooth stiffness is always positive and the analysis always 'converges'. Bifurcations are prevented due to the scaling technique.

• 한국건설순환자원학회논문집
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• 제9권4호
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• pp.650-657
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• 2021

광물질 혼화재를 자극하는 알칼리 활성화제는 고가의 소재이지만, 고 알칼리 성분의 산업부산물 대체하기 위해서는 제품성과 경제성을 모두 만족하여야 한다. 본 연구에서는 50MPa 이상의 고강도 콘크리트에 GGBFS의 알칼리 활성 반응을 위한 목적으로 LCD 제조 공정에서 발생하는 알칼리 산업부산물(LW)을 사용하였다. LW을 혼입한 콘크리트는 작업성이 다소 저하되었으나, 압축강도가 증진되는 특징이 있었다. ACI 209.2R-08 압축강도 모델식을 이용하여 분석하여 LW 혼입에 따른 강도계수의 변화를 비교하였다. 콘크리트의 내구성능 시험에서도 염화물 침투 저항성 및 탄산화 저항성에서 우수한 성능을 나타내었다. 단열온도 상승시험 결과에서는 LW를 혼입하면 초기 수화열이 빨라지는 효과가 있으나, 최종 단열온도상승량은 LW의 혼입 유, 무에 큰 영향을 받지 않았다.

• Earthquakes and Structures
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• 제20권4호
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• pp.377-388
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• 2021

Thin perforated Steel Plate Shear Walls (SPSWs) are among the most common types of seismic energy dissipation systems to protect the main boundary components of SPSWs from fatal fractures in the high-risk zones. In this paper, the cyclic behavior of the different circular hole patterns under cyclic loading is reported. Based on the experimental results, it can be concluded that a change in the perforation pattern of the circular holes leads to a change in the locations of the fracture tendency over the web plate, especially at the plate-frame interactions. Accordingly, the cyclic responses of the tested specimens were simulated by finite element method using the ABAQUS package. Likewise, perforated shear panels with a new perforation pattern obtained by implementing Topology Optimization (TO) were proposed. It was found that the ultimate shear strength of the specimen with the proposed TO perforation pattern was higher than that of the other specimens. In addition, theoretical equations using the Plate-Frame Interaction (PFI) method were used to predict the shear strength and initial stiffness of the considered specimens. The theoretical results showed that the proposed reduced coefficients relationships cannot accurately predict the shear strength and initial stiffness of the considered perforated shear panels. Therefore, the reduced coefficients should be adopted in the theoretical equations based on the obtained experimental and numerical results. Finally, with the results of this study, the shear strength and initial stiffness of these types of perforated shear panels can be predicted by PFI method.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제27권4호
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• pp.61-70
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• 2021

Purpose: The study aims at identifying patient-related and environmental factors associated with an increased risk of falling and, therefore, both caregivers and designers can be aware of fall risk factors and can contribute to prevent inpatient falls in their own areas of expertise. Methods: A case-control study has been conducted, utilizing patient data and physical environmental data in the unit of General Medicine in the United States. The case-control study investigated data about patients who had suffered falls as well as patients with similar characteristics (e.g., age, gender, and diagnosis) who did not suffer falls. Results: The study identified both patient-related and physical environmental factors associated with inpatient falls. Morse fall risk score, patient visibility, and patient accessibilityB were identified as significant predictors to inpatient falls, when controlling for other significant variables. Implications: The findings of the study can provide implications to both caregivers and healthcare and hospital environment designers. Caregivers should give special attention to patients with high Morse Fall Risk Scores to prevent inpatient falls. Designers also need to examine and to fine-tune the unit layout of inpatient care units to maximize each patient room's patient visibility from the rest of the unit and patient accessibilityB from working areas of nurses.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권3호
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• pp.174-181
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• 2004

In this paper, we review the four receiver architectures and four methods for multi-standard receiver design. Propose reconfigurable RF block can be used for both low-IF and direct conversion architecture. Also, using reconfigurable mixer method, it can be operated at $2{\sim}6$ GHz range for multi-standard receiver. It consists of wideband mixer, filter, and automatic gain control amplifier and to get wide-band operation, $2{\sim}6$ GHz, wide-band mixer use flexible input matching method. Besides, to design multi-standard receiver, LNA bank that support each standard is necessary and it has good performance to compensate the performance of wide-band mixer. Finally, we design and simulate proposed reconfigurable RF block and to prove that it has acceptable performances for various wireless standards, the LNA bank that supports both IEEE 802.11a/b/g and WCDMA is also designed and simulated with it.

• 전자통신동향분석
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• 제27권4호
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• pp.40-53
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• 2012

통신은 기본적으로 사람과 사람 간의 의사소통에서 출발한다. 그러나 만물지능통신은 통신의 대상을 사람-사물-공간-시스템으로 확장한 초연결(hyperconnectivity) 네트워킹을 전제로 한다. 본고에서는 이러한 만물지능통신 기반의 초연결 산업 구도를 분석하기 위하여, 스마트 혁명 이후의 IT 산업 분석틀로 부상한 CPNT(Content, Platform, Network, Terminal) 계층구조를 적용함과 동시에 초연결 산업의 준거틀로 일본 경제산업성 기술전략맵에 포함된 미래 사회의 삽화 내용을 원용했다. 동 기술전략맵에서는 2025년을 실현연도로 상정하여, 기술이 개발된 미래 생활환경을 삽화를 통하여 기술하고 있다. 동 삽화의 구도와 내용을 분석한 결과 초연결 산업은 사람-사물-공간-시스템 간의 초연결로 특징지을 수 있고, 콘텐츠-플랫폼-단말-네트워크 계층구조로 재구성할 수 있음을 확인할 수 있었다. 이러한 작업을 통하여 초연결 산업 생태계의 기본 구도로서 천지인(天地人) 모델을 제안하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제3권1호
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• pp.86-94
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• 2011

This paper compares frequency domain and time domain predictions from the ShipMo3D ship motion library with observed motions from model tests and sea trials. ShipMo3D evaluates hull radiation and diffraction forces using the frequency domain Green function for zero forward speed, which is a suitable approach for ships travelling at moderate speed (e.g., Froude numbers up to 0.4). Numerical predictions give generally good agreement with experiments. Frequency domain and linear time domain predictions are almost identical. Evaluation of nonlinear buoyancy and incident wave forces using the instantaneous wetted hull surface gives no improvement in numerical predictions. Consistent prediction of roll motions remains a challenge for seakeeping codes due to the associated viscous effects.