• Journal of the Korea Institute of Building Construction
• /
• v.16 no.2
• /
• pp.177-183
• /
• 2016

The daily report includes the most detailed information and various daily planning and performance data recorded at a site, and includes work types, the number of workers, and the equipment and materials used. However, in the daily reporting process, some information can be omitted or distorted or even made redundant due to there being several steps of manual input. For this reason, the daily report is utilized for a simple report rather than for an appropriate purpose. Thus, to resolve the issues of the existing daily report system mentioned above, a daily report system using a digital pen was developed and then applied to an actual construction site to verify its applicability. As a result, it was found that 96.610% recognition accuracy of handwritten letters could be achieved. In addition, it was no longer necessary to enter the same information multiple times and no additional training or education for using a mobile device was needed. The digital pen-based daily report program developed in this study is expected to contribute to an improvement of information management efficiency and site document management work by addressing the problems of the existing report system.

• Journal of Digital Contents Society
• /
• v.14 no.1
• /
• pp.15-23
• /
• 2013

In response to the demands of large-scale data processing with low-power and new application, a storage system using SSD (Solid State Disk/Drive) with fast input-output performance instead of hard disc has appeared as storage device. Studies on methods to overcome specific problems of SSD such as various processing data units, out-place-update and limited delete count have been actively conducted. However, declining performance and stability have not been resolved yet when storing case specific data with small scale that causes frequent random write in hard disc or SSD. This thesis suggests a system structure that stores index requesting frequent random write in NVRAM capable of byte access by using characteristics such as byte unit fast read / write of NVRAM, non-volatile and smaller size of actual changed data size in index page than block size.

• Journal of Convergence for Information Technology
• /
• v.8 no.2
• /
• pp.233-238
• /
• 2018

SMEs and small enterprises are making various attempts to manage SMEs in terms of equipment, safety and energy management as well as production management. However, SMEs do not have the investment capacity and it is not easy to build a smart factory to improve management and productivity of SMEs. In this paper, we propose a smart factory construction algorithm that partially integrates the factory equipment currently operated by SMEs. The proposed algorithm supports collection, storage, management and processing of product information and release information through IoT device during the whole manufacturing process so that SMEs' smart factory environment can be constructed and operated in stages. In addition, the proposed algorithm is characterized in that central server manages authentication information between devices to automate the linkage between IoT devices regardless of the number of IoT devices. As a result of the performance evaluation, the proposed algorithm obtained 13.7% improvement in the factory process and efficiency before building the Smart Factory environment, and 19.8% improvement in the processing time in the factory. Also, the cost of input of manpower into process process was reduced by 37.1%.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.37 no.5
• /
• pp.39-48
• /
• 2000

We newly proposed a polymer based vertical asymmetric optical coupler, which was characterized by simple fabricating procedure and short coupling length. And we fabricated a thermo-optic modulator using the polymeric optical coupler. We optimized the proposed device by coupling characteristic analysis. In a TE polarized 1.33${\mu}{\textrm}{m}$ wavelength, we obtained very short coupling length(L=277.6${\mu}{\textrm}{m}$) with 0.4${\mu}{\textrm}{m}$ thickness of middle layer, high coupling efficiency(94%), and asymmetric vertical waveguides with n$_{u}$ = 1.522, n$_{l}$ = 1.51. We implemented vortical asymmetric thermo-optic modulator with lower inverted rib waveguide and upper slab waveguide. In the 600Hz bandwidth and 4.5㎽ input power, the extinction ratio of the mode was 17㏈ with an insertion loss of 4.5㏈.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.10 no.2
• /
• pp.134-142
• /
• 2010

A comparative study on the trade-off between the drive current and the total gate capacitance in double-gate (DG) and triple-gate (TG) FinFETs is performed by using 3-D device simulation. As the first result, we found that the optimum ratio of the hardmask oxide thickness ($T_{mask}$) to the sidewall oxide thickness ($T_{ox}$) is $T_{mask}/T_{ox}$=10/2 nm for the minimum logic delay ($\tau$) while $T_{mask}/T_{ox}$=5/1~2 nm for the maximum intrinsic gate capacitance coupling ratio (ICR) with the fixed channel length ($L_G$) and the fin width ($W_{fin}$) under the short channel effect criterion. It means that the TG FinFET is not under the optimal condition in terms of the circuit performance. Second, under optimized $T_{mask}/T_{ox}$, the propagation delay ($\tau$) decreases with the increasing fin height $H_{fin}$. It means that the FinFET-based logic circuit operation goes into the drive current-dominant regime rather than the input gate load capacitance-dominant regime as $H_{fin}$ increases. In the end, the sensitivity of $\Delta\tau/{\Delta}H_{fin}$ or ${{\Delta}I_{ON}}'/{\Delta}H_{fin}$ decreases as $L_G/W_{fin}$ is scaled-down. However, $W_{fin}$ should be carefully designed especially in circuits that are strongly influenced by the self-capacitance or a physical layout because the scaling of $W_{fin}$ is followed by the increase of the self-capacitance portion in the total load capacitance.

• Korean Journal of Optics and Photonics
• /
• v.17 no.2
• /
• pp.175-180
• /
• 2006

A single sideband(SSB) modulator operating at 5.5 GHz was fabricated by polarization inversion techniques. The dimension of domain inversion in a $LiINbO_3$ Mach-Zehnder structure was precisely controlled so that the RF signal applied on two Mach-Zehnder arms gives rise to $90^{\circ}$ effective phase difference. The single sideband suppression was maximized by optimization of the polarization status of the optical input and by the DC bias value. The fabricated device showed the center frequency of 5.8 GHz and the maximum sideband suppression of 33dB, where the bandwidth of 15 dB sideband suppression ranged over a 2.5 GHz span. The optical phase delay could be regulated by the DC bias voltage, fur example, the enhanced optical modulation sideband was distinctively switched from the upper sideband to the lower sideband by changing the DC bias voltage from 1.9 V to -10.6 V.

• Journal of Environmental Science International
• /
• v.17 no.12
• /
• pp.1381-1390
• /
• 2008

Emission characteristics of volatile organic compounds (VOCs) were investigated in the flue gas emitted from wood drying process for plywood manufacturing. The moisture content of raw timber was average 48%, and its density was $831.55kg/m^3$. But the moisture content of dried wood is needed less than around 10%, thus the moisture contents of flue gas should be remarkably high(about 18.2 V/V%). Therefore, the vapor in flue gas is equivalent to 320 ton-vapor/day when 1100 ton-wood/day is treated in the wood drying process. The temperature of flue gas ranges from $140^{\circ}C\;to\;150^{\circ}C$ in each dryer stack with exception of the input site of wood(about $110^{\circ}C$). The velocity of flue gas in each stack ranges from 1.7 to 9.7m/sec. In order to assess the concentrations and attribution rate of odorous compounds, it was analyzed about 40 VOCs in the flue gases. It was found that the major odorous compounds were 8 compounds, and the concentrations of major VOCs(ppm) were as follows; benzene: $0.054{\sim}0.052$, toluene: $1.011{\sim}2.547$, ethylbenzene: $0.472{\sim}2.023$, m,p-xylene: $0.504{\sim}3.245$, styrene: $0.015{\sim}0.148$, o-xylene : $0.271{\sim}1.097$, ethanol: $11.2{\sim}32.5$, ${\alpha}$-pinene: $0.908{\sim}10.578$, ${\beta}$-pinene: $0.982{\sim}14.278$. The attribution rate of terpenes (${\alpha}$-pinene, ${\beta}$-pinene) was about 60.56%, and that of aromatics and alcohols was about 22.77%, and 16.67%, respectively. It is suggested that the adequate control device should be used to control both the water soluble and non-soluble compounds because both compounds were mixed in flue gas.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.11 no.2
• /
• pp.129-136
• /
• 2018

The IEC 61850 communication standard is used worldwide, and within the country the new substation is built as a digital substation based on IEC 61850 from 2013, after field tests and R&D from 2007. Research on the development of digital substation operating system has been conducted mainly in large domestic companies, so the IED power application equipment for LCP are developed. However, there is still a lack of research in the field of systems that can accommodate all the field devices used for legacy substation and new digital substation. In this paper, we developed the 48VDC input modules and the 125VDC output modules which can construct proposed field information processing modules to IEC 61850 based type, and verified the field applicability from the state monitoring and control operation tests by using IEC 61850 client authentication program and Wireshark.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.8
• /
• pp.52-58
• /
• 2008

Ths paper describes the Dual-band switch which was proposed new structure that could improved the specification of broadband and designed by the optimized structure through simulation. The Dual-band switch with 2.4[GHz]/5.8[GHz] that can apply to 802.11a/b/g system that is commercialized present was studied to get a new structure with higher power, high isolation. The transmitter of switch was designed to operate a parallel switching element with stack structure of two FET. The receiver designed to have asymmetry structure that insert series FET in addition to basic serial/parallel FET. SPDT(Single Pole Double Throw) Tx/Rx FET switch is a device that can do switching from a port of input to two port of output. The fabricated SPDT switch has the characteristic of insertion loss of a below -3[dB] form DC to 6[GHz] and the isolation of a below -30D[dB](Rx mode).

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.24 no.5
• /
• pp.987-999
• /
• 2014

A PUF is embedded and implemented into a tag or a device, and outputs a noise y with an input of x, based on its own unique physical characteristics. Although x is used multiple times as inputs of PUF, the PUF outputs slightly different noises, ($y_1,{\cdots}y_n$), and also the PUF has tamper-resistance property, hence it has been widely used in cryptographic protocol. In this paper, we study how to design a PUF-based RFID authentication protocol in a secure and an efficient way. Compared with recent schemes, the proposed scheme guarantees both authentication and privacy of backword/forward under the compromise of long-term secrets stored in tag. And also, the most cost and time-consumming procedure, key recovery algorithm used with PUF, has been desgined in the side of RFID reader, not in the tag, and, consequently, gives possibility to minimize costs for implementation and running time.