• Journal of the Society of Naval Architects of Korea
• /
• v.53 no.2
• /
• pp.144-153
• /
• 2016

This paper aims to demonstrate the design, structure analysis, and hydrostatic pressure test of the cylinder used in 2000m water depth. The cylinder was designed in accordance with ASME pressure vessel design rule. The 1.5 times safety factor required by the general rule was applied to the design of the cylinder, because ASME rule is so excessive that it is not proper to apply to the hydrostatic pressure test. The finite element analysis was conducted for the cylinder. The cylinder was produced according to the design. The hydrostatic pressure test was conducted at the hyperbaric chamber in KRISO. The results of finite element analysis(FEM) and those of the hydrostatic pressure test were almost the same, which showed that the design was exact and reliable.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.113-116
• /
• 1999

This paper presents a hardware architecture of AAL(ATM Adaptation Layer) type 2 switch. The proposed architecture can assign and configure maximum AAL2 CID limit. AAL2 is the protocol which has been recommended by ITU-T and ATM-Forum for low bit rate delay sensitive services. The architecture assumes 155 Mbps STM-1/STS-3c physical interface, maximum VCC can be 64K connections. It can support maximum 16,384M AAL2 connections. For efficient use of peripheral memory, a concept of segment address was proposed. The proposed AAL2 switch hardware architecture can be used in ATM network as a standalone server or embedded module in a ATM switching system.

• Journal of the Korean Institute of Rural Architecture
• /
• v.19 no.1
• /
• pp.35-42
• /
• 2017

This study aims to investigate the change in building density and residential environment after the reconstruction of decrepit public rental housing complexes formed in accordance with the Land Readjustment Project during the 1970s-80s. The results of this study can be summarized as follows: First, in terms of change in residential environment after the reconstruction, floor plans that were limited to two to four types and to small apartments measuring $42.9m^2$(13py)-$56.1m^2$ (17py) became varied, presenting 5-6 types of floor plans and various sizes of apartments. In particular, the reconstructed apartments were mainly built in a size smaller than 85($m^2$) and in the 3LDK floor plan and staircase-style unit architectural structure in order to reflect the lifestyle of residents. Second, in terms of change in building density after the reconstruction, the building coverage ratio did not change a lot, but the floor area ratio showed great change depending on the complex, ranging from a minimum of 2.9 times (Singdong Complex) to a maximum of 5.4 times (Eoyangdong Complex). Such change is attributable to the reconstruction policy that aims to improve the residential environment for original residents, secure economic feasibility and efficiency, and reflect the lifestyle of residents while incorporating dividends assigned to the existing housing project members as well as the maximum floor area ratio allowed by the regulation. Additionally, in terms of change in the number of floors and building density after the reconstruction, the former 5-story apartments were changed to apartments with 16-28 stories. Accordingly, the number of households in each complex has also increased by 20%. Third, according to the characteristics of parking facilities in terms of the size and density of parking spaces, former apartment complexes had only aboveground parking lots, not underground parking area. The newly constructed apartment complexes have underground parking space, and the parking-housing ratio is 1.1-1.3 cars.

• Korean Journal of Environment and Ecology
• /
• v.27 no.5
• /
• pp.579-591
• /
• 2013

This study was carried out to investigate the actual vegetation, the structure of plant community, and ecological succession sere of forest ecosystem in temperate northern climate zone, Daegwallyeong Ranch, Gangwon-do (Province) and to offer the basic data for planning of the forest managemant. As a result of analysis of actual vegetation, vegetation types divided into 56types and the area of survey site was $19,397,361m^2$. The ratio of vegetation type dominated by Quercus mongolica forest was 39.1%, primary grassland was 24.7%, Quercus mongolica-Deciduous broad-leaved forest was 11.3%. Twenty eight plots (size is $20m{\times}20m$) were set up and the results analyzed by DCA which in one of the ordination technique showed that the plant communities were divided into six groups which area community I (Pinus densiflora-Quercus mongolica community), community II (Quercus mongolica-Pinus densiflora community), community III (Quercus mongolica community), community IV (Quercus mongolica-Deciduous broad-leaved community), community V (Deciduous broad-leaved community), community VI (Sorbus alnifolia community). The age of community Iwas ranged from 57 to 62 years old, that of community IIwas ranged from 41 to 77 years old, community III was ranged from 47 to 108 years old, community IV was ranged from 47 to 82 years old, community V was 47 years old, community VI was 55 years old, thus we supposed that the age of the study site is about from 41 to 108 years old. The Ecological succession is predicted from Pinus densiflora community to Quercus mongolica community and Deciduous broad-leaved were distributed in the center of the valley in Daegwallyeong Ranch. According to the index of Shannon's diversity (unit: $400m^2$), community IV was ranged from 0.8203 to 1.1439, community III was ranged from 0.8019 to 1.1375, community V was 1.0993, community I was ranged from 0.9475 to 1.0797, community II was ranged from 0.6896 to 1.0324, community VI was 0.9909.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.8 no.1
• /
• pp.37-44
• /
• 2005

Nitrate($NO_3-N$) and total nitrogen(TN) removal by a reed wetland with open water(Wetland 1) was compared with that of a reed wetland without open water(Wetland 2) from March to October 2002. The two wetlands were 25mL by 6mW. An open water area, 3mL by 6mW was designed at the middle of Wetland 1. Reeds(Phragmites australis) were transplanted into the wetlands in June 2000. Water of Sinyang Stream flowing into the Kohung Estuarine Lake located in the southern part of Korea was pumped into a primary treatment pond, whose effluent was discharged into the secondary pond. Effluent from the secondary pond was funneled into the wetlands. Inflow into the wetlands averaged about 20.0$m^3$/day and their hydraulic retention time was approximately 1.5 days. Average $NO_3-N$ removal by Wetland 1 was 117.61mg/$m^2{\cdot}day$ and that by Wetland 2 was 106.39mg/$m^2{\cdot}day$. $NO_3-N$ removal efficiency of Wetland 1 and 2 was 37% and 34%, respectively. TN removal by Wetlands 1 and 2 averaged 226.80 and 214.54mg/$m^2{\cdot}day$, respectively. TN abatement efficiency of Wetland 1 was 43% and that of Wetland 2 was 40%. $NO_3-N$ removal efficiency of Wetland 1 was significantly higher(p=0.038) than Wetland 2. TN removal efficiency of Wetland 1 was also significantly higher(p=0.044) than Wetland 2. The wetland with open water was more efficient for removal of $NO_3-N$ and TN than one without.

• Korean Journal of Environment and Ecology
• /
• v.28 no.2
• /
• pp.128-141
• /
• 2014

This study established a plan to establish the roadside green for enhancing the urban green network and enhancing of urban greenery in Songpa-gu. As for the present conditions of the streets, that of the parks, the green axes, sidewalk in Songpa-gu were analyzed. This study derived 19 parks by the roadside and 13 lines to connect green axes. The result of roadside greenery status were selected 56,546m lines by natural green space and constructed green space. The result of sidewalks width were selected 8,600m lines that sidewalks width more than 5m for enhancing urban green network in Songpa-gu. For enhancing the urban green network lines were selected: Olympic Expressway, Songpa-daero, Nambusunhwan-no and Wiryeseong-gil. To improve the street planting strips, two plans were suggested: to improve the green structures of the street planting strips mainly with shrubs and to effectively create street planting strips through the green spaces along the streets. A plan to promote the amount of planting street trees in Songpa-gu analyzed the streets. Complements the understory layer sections were the highest the entire length of 34,206 m of 63.6% in strengthening for network streets. Greenspace network streets were calculated for planting of volume by promotion plan. Planting volume increased 4,708 trees before expand planting plan, so the total tree was considered 9,518 trees.

• Journal of the Korean Solar Energy Society
• /
• v.34 no.1
• /
• pp.72-80
• /
• 2014

This study proposed a wind power generation system utilizing outdoor air on the rooftop and indoor ventilation, which would increase according to the building height, as a way to help to save energy consumption in a building by using wind power energy of the new renewable energy sources. The study measured the distribution of air currents and power generation according to the usage factor of exhaust pipes in the kitchen and bathroom and identified the elements to consider when applying a wind power generation system to buildings in order to use outdoor air on the rooftop increasing according to the height and the indoor ventilation produced in the facility vertical shafts inside the buildings by installing a wind power generation system on the rooftop. (1) The study measured the ventilation velocity of the kitchen hood and bathroom ventilation fan by changing the zone areas by the households according to the usage factor of [${\alpha}$]=33~100%. As a result, the kitchen ventilation pipe generated the ventilation wind of 3.0m/s or more at the usage factor of [${\alpha}$] 66% or higher, and the bathroom ventilation pipe generated ventilation velocity lower than 3.0m/s, the blade velocity of the wind power generator, even after the usage factor rose to [${\alpha}$]=100%. (2) As the old bathroom ventilation pipe generated the ventilation velocity of 3.0m/s, the blade velocity of the wind power generator, even with the rising usage factor [${\alpha}$], the application of an outdoor air induction module increased the ventilation velocity by 2.9m/s at the usage factor of [${\alpha}$]=33%, 3.8m/s at the usage factor of [${\alpha}$]=66%, and 3.6m/s at the usage factor of [${\alpha}$]=100%. Thus the ventilation velocity of 3.0m/s, the blade velocity of the wind power generator, or higher was secured. (3) The findings prove that the applicability of a wind power generation system using outdoor air on the rooftop and indoor ventilation is excellent, which raises a need for various efforts to increase the possibility of its commercialization such as securing its structural stability according to momentary gusts on the rooftop and typhoons in summer and making the structure light to react to the wind directions of outdoor air on the rooftop according to the seasons.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.27 no.3
• /
• pp.71-78
• /
• 2021

Purpose: It is important to plan the ward module at a time when the size of beds, the floor area, and the construction budget are all set prior to the hospital design. In this context this study aims (1) to derive various factors affecting the ward module, and (2) to analyze the appropriate room module according to the type. Methods: Design factors related to hospital modules are derived through precedential studies, and the types of ward elevation are classified by reviewing the drawings of 18 case hospitals. And the detailed dimensions and area of the derived elements are analyzed. Results: The X-axis modules of the ward are switched to long span structural columns of 9.9 m, 12.6 m and 13.2 m, but the ward modules still represent 6.6 m. The Y-axis module of the ward shows a dimension of 9 to 9.9m in the process of changing a multi-person room into a four-person room. Type A of curtain wall with columns located on the wall of the room and type B of curtain wall located in the center of the room are analyzed due to their variations. The square window type, which forms the elevation of the square window by exposing the columns to the elevation, and the outframe type, which protrudes from the structural columns and beams, have elevation designs limited. There are, however, no obstacles to the interior space of the hospital room, so the wall composition and furniture arrangement are expected to be free. The ward area of Curtain Wall Type A, which can secure an effective area of 5.9m*5.0m, are 52.1m². The Curtain Wall Type A, Square window type, and the outframe type are 49.8m². Implications: As part of the hospital standard module plan for economical and reasonable hospital building planning, a type was proposed in this study in conjunction with the external design. It is hoped that it be a base for standard module research linked together to the Central Treatment department, Outpatient department and underground parking lot.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.47 no.12
• /
• pp.39-47
• /
• 2010

This paper proposes a fully-utilized block-based 2D DWT architecture, which consists of four 1D DWT filters with two-channel QMF PR Lattice structure. For 100% hardware utilization, we propose a new method which processes four input values at the same time. On the contrary to the image-based 2D DWT which requires large memories, we propose a block-based 2D DWT so that we only need 2MN-3N of storages, where M and N stand for filter lengths and width of the image respectively. Furthermore, the proposed architecture processes in horizontal and vertical directions simultaneously so that it computes the DWT for an $N{\times}N$ image within a period of $N^2(1-2^{-2J})/3$. Compared to existing approaches, the proposed architecture shows 100% of hardware utilization and high throughput rate. However, the proposed architecture may suffer from the long critical path delay due to the cascaded lattices in 1D DWT filters. This problem can be mitigated by applying the pipeline technique with maximum four level. The proposed architecture has been designed with VerilogHDL and synthesized using DongbuAnam $0.18{\mu}m$ standard cell.

• Journal of KIISE:Computer Systems and Theory
• /
• v.31 no.1_2
• /
• pp.51-58
• /
• 2004

Most of pubic-key cryptosystems are built on the basis of arithmetic operations defined over the finite field GF$GF(2^m)$ .The other operations of finite fields except addition can be computed by repeated multiplications. Therefore, it is very important to implement the multiplication operation efficiently in public-key cryptosystems. We propose an efficient bit-parallel normal basis multiplier for$GF(2^m)$ fields defined by All-One Polynomials. The gate count and time complexities of our proposed multiplier are lower than or equal to those of the previously proposed multipliers of the same class. Also, since the architecture of our multiplier is regular, it is suitable for VLSI implementation.