• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.5
• /
• pp.1540-1560
• /
• 2022

Latest technological innovation in the development of compact lower power radios has led to the explosion of Internet of Things. With Wi-Fi, Zigbee and other physical layer protocols offering short coverage area there was a need for a RF protocol that had a larger coverage area with low power consumption. LoRa offers Long Range with lower power consumption. LoRa offers point to point and point to multipoint connections. with Single hop communication in place the need for routing protocols are eliminated. LoRa Wide Area Network stack can accommodate thousands of nodes under a single LoRa gateway with a single hop communication between the end nodes and LoRaWAN gateway. This paper takes an experimental approach to analyze the basic physical layer parameters of LoRa and the practical coverage offered by a LoRaWAN under highly dense urban conditions with variable topography. The insights gained from the practical deployment of the LoRaWAN network, and the subsequent performance analysis is used to design a novel public utility monitoring platform. The second half of the papers is designing a robust platform to integrate both existing wired sensor water meters, current and future generation wireless water meters. The Common Automated Metering Platform is designed to integrate both wired sensors and wireless (LoRaWAN and Wi-Fi) supported water meters. This integrated platform reduces the number of nodes under each LoRaWAN gateway and thus improves the scalability of the network. This architecture is currently designed to accommodate one utility application but can be modified to integrate multi-utility applications.

• Journal of the Korean Home Economics Association
• /
• v.39 no.10
• /
• pp.97-109
• /
• 2001

It is thought that a composition of trousers is related to fabrics with single breadth. Therefore, trousers are designed with pattern using this fabrics with single breadth. However, in the old pattern of trousers, the breadth of 33cm-35cm was not considered in designing patterns. In this context, deciding which pattern design is better is not easy as there are a variety of estimation methods. So in this study, standardization of drafting is pursued by an objective pattern design. For this, a base angle of the trouser closely relating to a form and function was measured and using the height and the base angle, a trouser pattern design was tried. For a measurement of the base angle, 5 subject were selected. They are 25-29 year-old male graduates with fine physical standard. The base angle was measured with symphysis pubis point as a standard when subjects sat with their legs crossed, when they stood with their legs open (not forced artificially) and when they laid down with their legs open. The distance between a knee inside joint and knees was measured three times and the resultant value was used for the pattern design. For a design of trousers, the height was applied and the base angle was fixed. As a pattern drawing, using the height, a base angle and circumference of the hip, a trouser was designed. The production method for the pattern design is as follow: (1) The length formula, is height + $\frac{height}{2}$ (2) The hip girth formula is $\frac{hipgirth}{2}$ - $\frac{hipgirth}{20}$(3) A crotch angle is fixed at $72^{\circ}$. (4) The ratio of outer leg length to leg width is 5 : 8. (5) The component ratio of the upper outer leg length to the pant length is 5 : 8. (6) The ratio of the division point of front right inner leg length and left inner width to upper outer leg length is 5 : 8.

• Fashion & Textile Research Journal
• /
• v.7 no.1
• /
• pp.23-32
• /
• 2005

This study attempts to address the development processing of yarn-dyeing jacquard design by using jacquard textile design professional CAD system to create high valued worth products. To carry out this purpose, two kinds of necktie samples were designed and each of them was different in three types of weaving method. The results are as follows; All over type is appropriate when the motive's size is small. And the work can be finished within short time and design can be illustrated by basic jacquard system. However, one point type can represent rather big and audacious motive but it needs lots of working hours and jacquard system. Though the motives are identical, showed many changes in cubicle representation according to weaving methods and the structure. To express simple and modest design, single fabric woven is suitable and in the need of colorful and technical design, expressing by double weft cloths and triple weft cloths rather than single fabric woven are better to give creativity and colorfulness. For the production of jacquard design, cad system using ability is important but the understanding and study of the whole process of weaving development should be made.

• Journal of the Korean housing association
• /
• v.24 no.3
• /
• pp.9-18
• /
• 2013

This paper aims to investigate the design characteristics of a single housing block which is increasing in urban areas. For the analysis, all cases of single block housing in Daejeon metropolitan city were gathered into a database. Main concerns were on the location and the physical characteristics. The results of this study were as follows; 1) single block housing has been increasing both in the new developed areas and the existing urban areas 2) their location has shifted from residential districts to semi-residential and commercial districts. For this reason, the size and density has been increasing 3) the slab block with the hall type and the exterior corridor type were general in residential districts, diverse ones, however, including the point tower type were increasing with unusual circulation types such as central corridor, central core, double corridor, and mixed type in semi-residential and commercial districts 4) there were 5 types of access systems, and especially the street access and the piloti access were increasing, which were related with the high density.

• Proceedings of the KIEE Conference
• /
• 2003.11c
• /
• pp.608-611
• /
• 2003

A large part of the embedded system, compared with the PC, have low performance CPU and small memory. So the embedded operating system fits the condition of that hardware system. A Single Address Space (SAS) OS has the operating system and all applications in the single address space. The SAS architecture enhances sharing and co-operation, because addresses have a unique interpretation. Thus, pointer-based date structures can be directly communicated and shared between programs at any time, and can be stored directly on storage. The key point of the SAS OS on the embedded system is the low overhead inter-action between programs in process and usage. So SAS OS can be ported on the low performance CPU. In this paper, we design the SAS OS (named emNOS, Embedded Network Operating System) on the ARMTTDMI processor. Finally we show the benefits of the SAS OS on the embedded system.

• Honam Mathematical Journal
• /
• v.4 no.1
• /
• pp.147-154
• /
• 1982

Estimation methods of missing points for an experimental design are described. Formulae are provided for the estimation of missing points using matrix notation. The correct analysis of variance table is given. Estimation methods of a single missing point and two missing points in $2^{n}$ factorial designs are described.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.11 no.3
• /
• pp.270-276
• /
• 2018

This paper presents a low area 256-point pipelined FFT architecture, especially for IEEE 802.16a WiMAX systems. Radix-24 algorithm and single-path delay feedback (SDF) architecture are adopted in the design to reduce the complexity of twiddle factor multiplication. A new cascade canonical signed digit (CSD) complex multipliers are proposed for twiddle factor multiplication, which has lower area and less power consumption than conventional complex multipliers composed of 4 multipliers and 2 adders. Also, the proposed cascade CSD multipliers can remove look-up table for storing coefficient of twiddle factors. In hardware implementation with Cyclone 10LP FPGA, it is shown that the proposed FFT design method achieves about 62% reduction in gate count and 64% memory reduction compared with the previous schemes.

• Journal of the Korean Society of Safety
• /
• v.14 no.1
• /
• pp.66-72
• /
• 1999

Local heating transportation pipe has sensor and return lines to detect water-leakage. There are impulse and resistance comparison measurement types for a water-leakage detection. The impulse type shows large detection error within a measurement range. Since the resistance comparison type can find a comparative accurate single water-leakage point in the measurement range of heating pipe, it has been used to detect water-leakages these days. However if the multi water-leakages are happened in the measurement range of transportation pipe. the resistance comparison type shows a detection error point by the parallel resistance between a detection sensor line and ground. But the detection error will be minimized by the divided transportation pipe loops. In this research, it suggests the design of remote controlled detection system which can divide a large pipe loop and a possible single water-leakage measurement process in each divided loops.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.10 no.2
• /
• pp.90-95
• /
• 2011

This paper presents the study on the contact stress analysis of a pair of mating helical gears for turbo blower during rotation. Turbo blowers need high speed rotation of impeller in structure and high rate gear ratio. The use of helical gear indicated that noise was an important problem when the application involves high speeds and large power transmission. An example is presented to investigate the variation of contact stress on a pair of mating gears with contact positions. The variation of contact stress during rotation is compared with the contact stress at the lowest point of single tooth contact(LPSTC) and AGMA Equation for contact stress. In this study, the gear design considering the contact stress on a pair of mating gear is more severe than that of AGMA standard.

• Current Optics and Photonics
• /
• v.6 no.2
• /
• pp.171-182
• /
• 2022

A single-photon laser and mid-wave infrared (MWIR) common aperture optical system was designed and developed to detect and range a long-distance civil aviation aircraft. The secondary mirror of the Ritchey-Chretien (R-C) optical system was chosen as a dichroic lens to realize the design of a common aperture system for the laser and MWIR. Point spread function (PSF) ellipticity was introduced to evaluate the coupling efficiency of the laser receiving system. A small aperture stop and narrow filter were set in the secondary image plane and an afocal light path of the laser system, respectively, and the stray light suppression ability of the small aperture stop was verified by modeling and simulation. With high-precision manufacturing technology by single point diamond turning (SPDT) and a high-efficiency dichroic coating, the laser/MWIR common aperture optical system with a 𝜑300 mm aluminum alloy mirror obtained images of buildings at a distance of 5 km with great quality. A civil aviation aircraft detection experiment was conducted. The results show that the common aperture system could detect and track long-distance civil aviation aircraft effectively, and the coverage was more than 450 km (signal-to-noise ratio = 6.3). It satisfied the application requirements for earlier warning and ranging of long-range targets in the area of aviation, aerospace and ground detection systems.