• Journal of Korea Society of Industrial Information Systems
• /
• v.27 no.5
• /
• pp.25-36
• /
• 2022

This paper proposes a random sign reversal technique in space frequency block code for single carrier modulation. The traditional space time and frequency block coding technique may be confronted with radio environments openly, severe radio hijacking problems are to be overcome. In order to avoid such an open radio issue, random coded data protection technique for space-time block code was proposed, but this algorithm can change channel combination per an Orthogonal Frequency Division Multiplexing block. This kind of slow switching increases the probability that nearby receivers will detect the transmitted data. This paper proposes a fast switching algorithm per data symbols' basis which is a random sign reversal technique in space frequency block code for Single Carrier Modulation. It is shown in simulation that the proposed one has a superior performance in comparison with the performance of the receiver which do not know the random timing sequence of sign reversal.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.5
• /
• pp.2267-2271
• /
• 2011

This study was focused on getting p-type copper-oxide thin-film semiconductors suitable for p-channel thin-film transistors. Vacuum thermal evaporation and thermal annealing were used to get copper-oxide thin-film semiconductor having properties adoptable as an active layer of thin-film transistors. n-type thin films having electron carrier density of about $10^{22}\;cm^{-3}$ before thermal annealing was converted to p-type thin films having hole carrier density of about $10^{16}\;cm^{-3}$ as the thermal annealing conditions were optimized.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.2
• /
• pp.588-593
• /
• 2011

For the progressive notching and forming die, analyzing beforehand according to the interpretation of thin plate molding for massive production is essential. In this study, we dealt with Ez5 particularly its strip layout design based on the exported die as ordered by Japanese S automobile company's local factory in the USA. We completed the strip layout design consisting of 13 processes by optimizing the blank layout with arrays of a single carrier with wide width drawn in 1 row. This type of die is expected to be ordered in bulk frequently and at the same time via the Internet; any company with die technology will be required to cope with such type of die.

• Journal of Korea Society of Industrial Information Systems
• /
• v.16 no.4
• /
• pp.19-26
• /
• 2011

Relay-assisted multiple input multiple output (MIMO) technique has become a promising candidate for next generation broadband wireless communications. In this paper, we propose maximum ratio combining (MRC) minimum mean-square-error (MMSE) equalization for single carrier-frequency domain equalizer (SC-FDE) in amplify-and-forward (AF) relaying networks. The performance of SC-FDE system can be improved considerably by achieving both the diversity gain and the MMSE equalization gain when the signals from source-destination (S->D) and source-relay-destination (S->R->D) are combined and equalized by means of the MMSE criteria. We find the weighting coefficients of MRC combining and the tap coefficients of MMSE equalizer for SC-FDE in AF relaying networks. Simulation results show that the proposed relay-based system considerably outperforms the conventional SC-FDE system.

• Journal of Korea Society of Industrial Information Systems
• /
• v.22 no.6
• /
• pp.1-7
• /
• 2017

This Paper Addresses a Performance Enhancement of Multitude Receivers Communicating with a Basestation. A General Link between Basestation and Terminal is that a Basestation is connected with Multitude Receivers and Time, Frequency and Code are shared and used among them. We propose an Algorithm of Enhancing Receiver Capability at the Receiver when access Point of Acting as a Basestation in this Environment Modifies Transmission Data Separately to be sent. In the Proposed Algorithm, we configure Transmit Data to Use Maximal Ratio Combining Technique in the Receiver, and Estimate Transmitter Signal per Each Receiver and Simulate Bit Error Rate and Show the Performance Results.

• Journal of the Semiconductor & Display Technology
• /
• v.19 no.2
• /
• pp.105-109
• /
• 2020

Today's placement machines can pick and place thousands of components per hour with a very high degree of accuracy. The packaged semiconductor chips are inserted into a carrier at regular intervals, covered with a tape to protect the chips from external impact, and supplied in a roll form. These packaging processes also progress rapidly in a consistent direction, affecting the peelback strength between the cover tape and carrier depending on the main process conditions. In this paper, we analyzed the main process variables that affect peelback strength in the reel tape packaging process for packaging semiconductor chips. The main effects and interactions were analyzed. The peelback strength range required in the packaging process was set as the nominal the best characteristics, and the optimum process condition satisfying this was derived.

• Journal of the Korean Ceramic Society
• /
• v.50 no.4
• /
• pp.288-293
• /
• 2013

Zn-In-Sn-O films were prepared at room temperature by combinatorial RF-magnetron co-sputtering system. The cationic contents of the films were varied using a compositionally combinatorial technique. The effects of the oxygen partial pressure and film compositionon the structural and electrical properties were investigated. The Zn-In-Sn-O films deposited at Ar gas atmosphere showed an amorphous phaseirrespective of the film composition. However, the amorphous Zn-In-Sn-O films with a Zn content below 30.0 at% were converted into a bixbyite type-ITO polycrystalline phase with an increase in the oxygen partial pressure. The resistivity, carrier concentration, and Hall mobility were strongly affected by the oxygen partial pressure and chemical composition of the film. At sufficiently high carrier densities above $5{\times}10^{18}cm^{-3}$, the conduction behavior of amorphous Zn-In-Sn-O film changes from thermally activated to degenerate band conduction accompanied with high mobility.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.11
• /
• pp.7456-7462
• /
• 2015

This paper proposes a spectral efficient space-frequency(SF) block coded single carrier-frequency division multiple access(SC-FDMA) transmission system in a relaying multi-path shadow area. The cyclic prefix(CP) is not used in the proposed system in order to prevent a loss of spectral efficiency due to the use of CP. The destruction of channel cyclicity due to the lack of CP is recovered at the receivers of relays and a destination station. Simulation results show that the performance of the proposed system without CP is almost same as that of the conventional system with full CP, thus increasing the spectral efficiency.

• Journal of Korea Society of Industrial Information Systems
• /
• v.25 no.6
• /
• pp.55-67
• /
• 2020

This study aims to investigate which job crafting has impact on person-job fit and job satisfaction. We define the concept of job crafting, person-job fit and job satisfaction based on previous literatures and analyze the relationship between variables. The research sample was collected from ground staffs of Low Cost Carrier (LCC) working in Incheon international airport. Results show that the cognition crafting influences on person-job fit of ground staff, and the person-job fit has been verified as a positive effect on job satisfaction.

• Journal of Korea Society of Industrial Information Systems
• /
• v.14 no.5
• /
• pp.1-9
• /
• 2009

Relay-assisted multiple input technique has become a promising candidate for next generation broadband wireless communications. In this paper, we propose channel selective relay-based multiple input transmission system. In the proposed system, single carrier frequency division multiple access (SC-FDMA) and orthogonal frequency division multiple access (OFDMA) are adopted for uplink and downlink transmissions, respectively. The performance of relay-based system can be improved by using the subcarriers selectively based on the channel condition between relay station (RS) and mobile station, or between RS and base station. Simulation results show that the proposed relay-based system considerably outperforms the conventional relay-based system.