• The KIPS Transactions:PartC
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• v.9C no.4
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• pp.523-530
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• 2002

Earlier efforts on optical access concentrated on the design of PONs for the collection and distribution portion of the access network. PON architecture is very simple but it requires MAC protocol for control of upstream traffic. This paper proposes a MAC protocol for a broadband access network using an ATM Passive Optical Network supporting CBR/rtYBR, nrtYBR, UBR and ABR traffic. For the proposed MAC scheme, we present grant field format, minislot format, and bandwidth allocation algorithm. From the simulation result, we have confirmed that our proposed scheme can reduce the average cell delay in comparison to that of conventional MAC schemes.

• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.128-136
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• 2005

The objective of this study was to determine the effect of calcium concentrations in fertilizer solution on growth and cut flower quality of chrysanthemum 'Biarritz' To achieve this, deficiency symptom and growth characteristics as influenced by controlled Ca concentrations in fertilizer solution were investigated. The analysis of plant tissue and soil solution of root media were also conducted to secure optimum concentration for plant growth. Calcium deficiency developed on the very youngest leaves and the young leaves developed 'cupped' shape as they expand. The cut flower length of 0, 3.0 and 6.0 mM treatments were 105.8, 106.5, and 107.3cm, respectively. Elevated Ca concentration within the range from 0 to 6.0mM in fertilizer solution increased cut flower weight. The cut flower weight of control and 6.0mM treatment were 51.6 and 59.4 g, respectively. The tissue Ca content of 6.0mM treatment in which crops showed the highest growth among treatments was $3.09\%$ based on the dry weight of the youngest fully expanded leaves. From the results, it seems necessary to maintaining tissue Ca content higher than $2.8\%$. Soil Ca concentrations increased as K concentrations in fertilizer solution were elevated. Ca concentration in 0.0, 1.5, 3.0, 4.5 and 6.0mM treatments were 5.0, 7.4, 12.1, 16.5 and $28.2mg{\cdot}L^{-1}$, respectively, at harvesting stage. It is suggested that Ca concentration higher than $25.4mg{\cdot}L^{-1}$ in soil solution of root media is required to maintain normal growth.

• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.8-20
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• 2006

This research was conducted to determine the plant growth and nutrient contents of potted chrysanthemum 'Lima Honey' as influenced by application rate of dolomite in three root media, peatmoss+vermiculite (1:1, v/v), peatmoss+composted rice hall (1:1, v/v), and peatmoss+composted pine bark (1:1, v/v). All root media contained polyacrylic acid sodium salt (PASS) at a rate of $4.5g L^{-1}$. In crop growth at 40 and 80 days after transplanting, elevated application rates of dolomite up to $6.0g L^{-1}$ in three root media increased fresh and dry weights per plant. But the treatment of $9.0g L^{-1}$ had less fresh and dry weights than those of $6.0g L^{-1}$. Tissue phosphorus content decreased and those of Ca and Mg increased by the elevated application rates of dolomite. Elevated application rates of dolomite in three root media resulted in the increase of pH, EC, and the concentrations of K, Ca, and Mg at 43 days after transplanting. Those at 80 days after transplanting were also increased, but the differences among treatments were less significant as compared to those at 43 days after transplanting. From the results of dry weight in potted chrysanthemum 'Lima Honey', the proper application rate of dolomite to three root media containing PASS at a rate of $4.5g L^{-1}$ were $6.0g L^{-1}$.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.281-285
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• 2012

The aim of this research was carried out that leafty and tonic vegetable using garlic (Allium victorialis L. var. platyphyllum Makino) makes use of landscape ground-cover plant. Following shading level treatments (30%, 50%, 80%), garlic was cultivated to investigate plant growth characteristic and chlorophyll content. Leaf number of all treatments was unaffected, and 80% shading treatment had grown vigorous growth 16.8 cm leaf length and 10.1 cm leaf width compared to 13.4 cm leaf length and 7.3 cm leaf width for the non-shading treatment. Fresh weight of non-shading treatment was better than those of three shading treatments, however, 80% shading treatment had produced 10.4 g fresh weight of stem part compared to 8.5 g for the for the non-shading treatment. The chlorophyll content of the 50 and 80 shading treatments showed 42.8% and 40.5% respectively. These treatments increased 36.7% chlorophyll content compared to non-shading treatments. Following shading level treatments, growth characteristics of garlic in 80 shading level treatment shows outstanding growth and it is worthy of planting as shading ground-cover plants.

• Korea Science and Art Forum
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• v.37 no.4
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• pp.205-216
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• 2019

Today, there have been more museums with architectural freeform structure. From an academic perspective, that caused a change in the paradigm of the genealogy of architectural forms. Accordingly, it has been required to find whether the freeform architecture influences an exhibition space. Therefore, in order to analyze the correlation between freeform architecture and exhibition space, this study looks into the tendency of actual freeform architecture through case analysis after 2000. An exhibition space of museum serves as a socially, culturally, and locally symbolic icon and has the function of delivering information to viewers through the aesthetic presentation of articles on exhibition. This study is meaningful in the point that it drew the conclusion of the correlation between freeform architecture and exhibition space in order to infer that a freeform exhibition space is more effective at viewers' spatial experience. The method and results of this study are presented as follows: Firstly, literature survey on the concept of the freerform architecture of museum and the classification of architectural forms was conducted and previous studies were analyzed in order to establish criteria. Secondly, a case study was conducted through visits to Singapore, Germany, and the Netherlands in order to look into the current state and characteristics of freeform architecture and exhibition space. In this case, Karel Vollers' architectural freeform criteria were used for analysis. Thirdly, to prove the correlation between freeform architecture and exhibition space, each case was cross-checked on the basis of Karel Vollers' architectural freeform criteria and freeform exhibition classification, and then results were drawn. The study results are presented as follows: Firstly, EX(angle, ortho) of freeform architecture had a significant correlation with the diagonal form of exhibition space. That was proved 92.3% accurately more in the Netherlands and Germany than in Singapore. However, the curve form of exhibition space had a unclear correlation. In Singapore case, the curve form correlation was made through RO, FR, and TW. Secondly, freeform architecture had complex-typed combination with the diagonal and curve forms of exhibition space. In particular, N-02 and G-02 had a combination form, basically EX, and partially various forms so as to induce the complexity of free form. As such, architectural freeform makes it possible to achieve infinite transformation in various combinations. For responses, combinational approaches are required in multilateral ways. Based on this study, it will be planned to analyze the correlation between freeform architecture of museum and exhibition presentation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.3
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• pp.63-81
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• 2013

The vascular plants in the Ohseosan and the Bongsusan, Chungnam were listed 439 taxa (9.0% of all 4,881 taxa of vascular plants); 95 families, 268 genera, 339 species, 5 subspecies, 75 varieties and 20 forms. Furthermore, the Ohseosan were listed 339 taxa and the Bongsusan were listed 306 taxa. So, Hemicryptophytes (H) were 107 taxa (24.4%), Therophytes (Th), Geophytes (G) same as were 82 taxa (18.7%) showed high proportional ratio in life form. Based on the list of rare plants, 4 taxa; Aristolochia contorta, Viola albida, Scutellaria insignis (LC) and Scrophularia koraiensis (DD) and endemic plants, 8 taxa; Aconitum pseudolaeve, Ajuga spectabilis, etc. Based on the list of specific plants, 35 taxa; Wisteria floribunda for. floribunda in class IV, 5 taxa (Scutellaria insignis, Scrophularia koraiensis, etc.) in class III, 5 taxa (Acer triflorum, Cymopterus melanotilingia, etc.) in class II, 24 taxa (Pyrus ussuriensis var. ussuriensis, Campanula punctata, etc.) in class I. Based on the list of naturalized plants, 9 families, 20 genera, 24 taxa (Persicaria orientalis, Carduus crispus, etc.) and ecosystem disturbing plants were Rumex acetocella, Ambrosia artemisiifolia. Naturalization rate was 5.5% of all 439 taxa of vascular plants and urbanization index was 7.5% of all 321 taxa of naturalized plants. In particular, for rare plants, in and ex-situ conservation of genetic resources must surely be done, by preserving present natural habitats, discovering additional natural habitats and securing seeds. Moreover, ecosystem disturbing plants require long-term monitoring and consistent management, since not only do they disturb the ecosystem in competition with Korean native species, but damage humans, too.

• Advances in Computational Design
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• v.3 no.4
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• pp.339-366
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• 2018

Parametric design systems serve as powerful assistive tools in the design process by providing a flexible approach for the generation of a vast number of design alternatives. However, contemporary parametric design systems focus primarily on low-level engineering and structural forms, without an explicit means to also take into account high-level, cognitively motivated people-centred design goals. We present a precedent-based parametric design method that integrates people-centred design "precedents" rooted in empirical evidence directly within state of the art parametric design systems. As a use-case, we illustrate the general method in the context of an empirical study focusing on the multi-modal analysis of wayfinding behaviour in two large-scale healthcare environments. With this use-case, we demonstrate the manner in which: (1). a range of empirically established design precedents -e.g., pertaining to visibility and navigation- may be articulated as design constraints to be embedded directly within state of the art parametric design tools (e.g., Grasshopper); and (2). embedded design precedents lead to the (parametric) generation of a number of morphologies that satisfy people-centred design criteria (in this case, pertaining to wayfinding). Our research presents an exemplar for the integration of cognitively motivated design goals with parametric design-space exploration methods. We posit that this opens-up a range of technological challenges for the engineering and development of next-generation computer aided architecture design systems.

• Journal of Ocean Engineering and Technology
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• v.29 no.4
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• pp.322-330
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• 2015

As a new technical approach, a hydraulic and magnetic clamp device was developed to realize a magnetic clamp crane system by simultaneously actuating eight individual hydraulic cylinders. In this approach, an Sr-type of ferritic permanent magnet (SrO· 6Fe₂O₃), rather than the previous electromagnet, was utilized for the purpose of lifting and transporting the large curved steel plates used for manufacturing ships. This study had the goal of developing and manufacturing a hydraulic, magnetic clamp prototype composed of three main parts, including the base frame, cylinder joint, and magnet joint, in order to safely transport curved steel plates. Furthermore, this research included a performance evaluation of the manufactured prototype and acquired the purposed quantity value in the performance test. The most significant item, the magnetic adhesive force (G), was evaluated in a performance test, which utilized a ferritic permanent magnet (Sr type) with 3700~4000 G of residual induction (Br) and 2640/2770 Oe of coercive force (Hc). In particular, relevant items such as the hoist tension (kN), transportation time (s), and applied load (Kgf) on the hydraulic cylinders were also evaluated in order to determine the optimum values.

• Steel and Composite Structures
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• v.49 no.4
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• pp.441-456
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• 2023

Aiming at the development trend of light weight and high strength of engineering structures, this paper experimentally investigated the seismic performance of circular-in-square high-strength concrete-filled double skin steel tubular (HCFDST) stub columns with out-of-code width-to-thickness (B/t) ratios. Typical failure mode of HCFDST stub columns appeared with the infill material crushing, steel fracture and local buckling of outer tubes as well as the inner buckling of inner tubes. Subsequently, the detailed analysis on hysteretic curves, skeleton curves and ductility, energy dissipation, stiffness degradation and lateral force reduction was conducted to reflect the influences of hollow ratios, axial compression ratios and infill types, e.g., increasing hollow ratio from 0.54 to 0.68 and 0.82 made a slight effect on bearing capacity compared to the ductility coefficients; the higher axial compression ratio (e.g., 0.3 versus 0.1) significantly reduced the average bearing capacity and ductility; the HCFDST column SCFST-6 filled with concrete obviously displayed the larger initial secant stiffness with a percentage 34.20% than the column SCFST-2 using engineered cementitious composite (ECC); increasing hollow ratios, axial compression ratios could accelerate the drop speed of stiffness degradation. The out-of-code HCFDST stub columns with reasonable design could behave favorable hysteretic performance. A theoretical model considering the tensile strength effect of ECC was thereafter established and verified to predict the moment-resisting capacity of HCFDST columns using ECC. The reported research on circular-in-square HCFDST stub columns can provide significant references to the structural application and design.

• Current Research on Agriculture and Life Sciences
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• v.25
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• pp.1-5
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• 2007

This study was carried out to offer the raw data of floricultural resource by scientific analyzing the growth and soil environment in Viola orientalis habitat, and establish the ecological characteristics in developing the relative model. In the results of soil factors analysis, there showed that acidity was pH 5.1, organic matter content of 9.1%, available $P_2O_5$ of 40.6mg/kg, exchangeable $K^+$ of $0.2cmol^+/kg$, exchangeable $Ca^{2+}$ of $3.5cmol^+/kg$, exchangeable $Mg^{2+}$ of $0.8cmol^+/kg$, cation exchange capacity(C.E.C) of $13.7cmol^+/kg$ and electrical conductivity(EC) of 0.4dS/m. The growth characteristics were surveyed that height was 12.4cm, leaf width of 2.5cm, leaf length of 3.0cm, flower width of 2.5cm, peduncle of 2.3cm and chlorophyll of $38.5{\mu}g{\cdot}mg^{-1}$.