• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.565-568
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• 2014

This paper presents a 0.2V DC/DC boost converter with regulated output for thermoelectric energy harvesting. To use low voltages from a thermoelectric device, a start-up circuit consisting of native NMOS transistors and resistors boosts an internal VDD, and the boosted VDD is used to operate the internal control block. When the VDD reaches a predefined value, a detector circuit makes the start-up block turn off to minimize current consumption. The final boosted VSTO is achieved by alternately operating the sub-boost converter for VDD and the main boost converter for VSTO according to the comparator outputs. When the VSTO reaches 2.4V, a buck converter starts to operate to generate a stabilized output VOUT. Simulation results shows that the designed converter generates a regulated 1.8V output from an input voltage of 0.2V, and its maximum power efficiency is 60%. The chip designed using a $0.35{\mu}m$ CMOS process occupies $1.1mm{\times}1.0mm$ including pads.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.6
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• pp.467-478
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• 2019

This paper describes the development and measurement results of a wide-band planar active phase array antenna system for an electronic warfare jamming transmitter. The system is designed as an $8{\times}8$ triangular lattice array using a $45^{\circ}$ slant wide-band antenna. The 64-element transmission channel is composed of a wide-band gallium nitride(GaN) solid state power amplifier and a gallium arsenide(GaAs) multi-function core chip(MFC). Each GaAs MFC includes a true-time delay circuit to avoid a wide-band beam squint, a digital attenuator, and a GaAs drive amplifier to electronically steer the transmitted beam over a ${\pm}45^{\circ}$ azimuth angle and ${\pm}25^{\circ}$ elevation angle scan. Measurement of the transmitted beam pattern is conducted using a near-field measurement facility. The EIRP of the designed system, which is 9.8 dB more than the target EIRP performance(P), and the ${\pm}45^{\circ}$ azimuth and ${\pm}25^{\circ}$ elevation beam steering fulfill the desired specifications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.581-584
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• 2014

In this paper, a micro-scale photovoltaic(PV) energy harvesting system is proposed where an MPPT(Maximum Power Point Tracking) control is implemented using an energy distribution technique. Miniature PV cells output very low energy and low voltages, and thus, they cannot be used to directly power the MPPT controller. In the proposed system, a start-up circuit boosts an internal Vcp, and the boosted Vcp is used to operate the internal MPPT control block. When the Vcp reaches a predefined value, a detector circuit makes the start-up block turn off and provide a power converter with the energy from the PV cell. When the Vcp decreases such that the MPPT controller can not be operated, the energy transferred to the power converter is blocked and the start-up circuit is reactivated. In this way, the MPPT function is achieved by alternately operating the start-up circuit and the power converter using the energy distribution technique, and the harvested energy is transferred to a load through a PMU(Power Management Unit). The proposed circuit is designed in a 0.35um CMOS process and its functionality has been verified through extensive simulations. The designed chip area including pads is $1430um{\times}1110um$.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.431-447
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• 2021

Recently, the use of high-resolution satellites is increasing in many areas. In order to supply useful satellite images stably, it is necessary to establish automatic precision geometric correction technic. Geometric correction is the process that corrected geometric errors of satellite imagery based on the GCP (Ground Control Point), which is correspondence point between accurate ground coordinates and image coordinates. Therefore, in the automatic geometric correction process, it is the key to acquire high-quality GCPs automatically. In this paper, we proposed iterative precision geometry correction method. we constructed an image pyramid and repeatedly performed GCP chip matching, outlier detection, and precision sensor modeling in each layer of the image pyramid. Through this method, we were able to acquire high-quality GCPs automatically. we then improved the performance of geometric correction of high-resolution satellite images. To analyze the performance of the proposed method, we used KOMPSAT-3 and 3A Level 1R 8 scenes. As a result of the experiment, the proposed method showed the geometric correction accuracy of 1.5 pixels on average and a maximum of 2 pixels.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.93-101
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• 2008

Side channel attacks are well known as one of the most powerful physical attacks against low-power cryptographic devices and do not take into account of the target's theoretical security. As an important succeeding factor in side channel attacks (specifically in DPAs), exact time-axis alignment methods are used to overcome misalignments caused by trigger jittering, noise and even some countermeasures intentionally applied to defend against side channel attacks such as random clock generation. However, the currently existing alignment methods consider only on the position of signals on time-axis, which is ineffective for certain countermeasures based on time-axis misalignments. This paper proposes a new signal alignment method based on interpolation and decimation techniques. Our proposal can align the size as well as the signals' position on time-axis. The validity of our proposed method is then evaluated experimentally with a smart card chip, and the results demonstrated that the proposed method is more efficient than the existing alignment methods.

• Journal of Practical Agriculture & Fisheries Research
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• v.17 no.1
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• pp.125-132
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• 2015

The report about equine anesthesias in Korea are very rare. This paper aimed at the mortality rate during anesthesia in Thoroughbred horses at Equine Hospital of Busan Race Park, KRA in South Korea from 2005 to 2010. Drugs used in anesthesia was IV injection of detomidine hydrochloride (0.01 mg/kg) or xylazine(0.5mg/kg) for sedation and premedication, Guaifenesin(50-100 mg/kg) for muscle relaxation, ketamine hydrochloride(2 mg/kg) for induction of anaesthesia and Inhalational isoflurane(1.3-1.5 %) to maintain anesthesia. Total number of anesthetic cases was 190, 150 of inhalational anesthesia and 40 of general anesthesia, repectively. The purpose of anesthesia was highest in the disorder of musculoskeletal system, followed by urogenital system and respiratory system Mortality case due to anesthesia was one during arthroscopic surgery for removal of osteochondral chip fragments. The time of anesthesia was 150 min, fatal sign was hypoxemia and the reason was improper machine operation of the anesthetist. In conclusion, the perianesthetic mortality rate during anesthesia in Thoroughbred horses at Busan Race Park was 0.52%(1 death per 190 anesthetics).

• Journal of the Korea Society of Computer and Information
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• v.14 no.2
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• pp.157-168
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• 2009

In this paper, a photovoltaic system is designed with a step up chopper and single phase PWM(Pulse Width Modulation) voltage source inverter. Where proposed Synchronous signal and control signal was processed by one-chip microprocessor for stable modulation. The step up chopper operates in continuous mode by adjusting the duty ratio so that the photovoltaic system tracks the maximum power point of solar cell without any influence on the variation of insolation and temperature because solar cell has typical voltage and current dropping character. The single phase PWM voltage source the inverter using inverter consists of complex type of electric power converter to compensate for the defect, that is, solar cell cannot be developed continuously by connecting with the source of electric power for ordinary use. It can cause the effect of saving electric power. from 10 to 20[%]. The single phase PWM voltage source inverter operates in situation that its output voltage is in same phase with the utility voltage. In order to enhance the efficiency of photovoltaic cells, photovoltaic positioning system using sensor and microprocessor was design so that the fixed type of photovoltaic cells and photovoltaic positioning system were compared. In result, photovoltaic positioning system can improved 5% than fixed type of photovoltaic cells. In addition, I connected extra power to the system through operating the system voltage and inverter power in a synchronized way by extracting the system voltage so that the phase of the system and the phase of single-phase inverter of PWM voltage type can be synchronized. And, It controlled in order to provide stable pier to the load and the system through maintaining high lurer factor and low output power of harmonics.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.967-971
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• 2023

Recently, a variety of AI-based platform services are available, and one of them is ChatGPT that processes a large quantity of data in the natural language and generates an answer after self-learning. ChatGPT can perform various tasks including software programming in the IT sector. Particularly, it may help generate a simple program and correct errors using C Language, which is a major programming language. Accordingly, it is expected that ChatGPT is capable of effectively using Verilog HDL, which is a hardware language created in C Language. Verilog HDL synthesis, however, is to generate imperative sentences in a logical circuit form and thus it needs to be verified whether the products are executed properly. In this paper, we aim to select small-scale logical circuits for ease of experimentation and to verify the results of circuits generated by ChatGPT and human-designed circuits. As to experimental environments, Xilinx ISE 14.7 was used for module modeling, and the xc3s1000 FPGA chip was used for module embodiment. Comparative analysis was performed on the use area and processing time of FPGA to compare the performance of ChatGPT products and Verilog HDL products.

• Applied Chemistry for Engineering
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• v.35 no.4
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• pp.335-340
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• 2024

In this paper, we synthesized organic and inorganic hybrid materials to introduce antibody functionality to UIO-66 and incorporated them into a surface plasmon resonance (SPR) assay to enhance the sensitivity of detecting small molecules such as oxytocin. A biological marker peptide called oxytocin may help in the diagnosis of heart failure, Alzheimer's disease, and cancer. To detect oxytocin at concentrations as low as a few femtomole (fM), we developed a surface sandwich assay utilizing a pair of oxytocin-specific antibodies for enhancing selectivity and one of metal organic frameworks [e.g., UiO-66-(COOH)₂] possessing high porosity and surface-area as a signal amplifier. Initially, real-time SPR assays were used to confirm that each selected oxytocin-specific antibody binds strongly to oxytocin and to different binding sites on oxytocin. One of these antibodies (e.g., anti-OXT[OTI5G4]) was immobilized on the surface of a thin gold chip. Upon sequential injecting of oxytocin and the other antibody (e.g., anti-OXT[4G11]) conjugated to UiO-66-(COOH)₂ onto the surface to form the surface sandwich complex of anti-OXT[OTI5G4]/oxytocin/UiO-66-(COOH)₂-anti-OXT[4G11]), SPR changes, which varied with oxytocin concentration, were then measured in real time. The results demonstrated that sensitivity was amplified by over a million-fold compared to assays without UiO-66-(COOH)₂, enabling oxytocin detection down to approximately 10 fM.

• Journal of International Area Studies (JIAS)
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• v.14 no.4
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• pp.79-106
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• 2011

The cultural contents industries have moved closer to the centre of the economic action in many countries and across much of the world. For this reason, the concern with the development of glocal cultural contents has also been growing. According to Goldman Sock's BRICs report, Indian economy will be the engine of global economy with China. In addition, India will be a new blue chip country for large consumer market of cultual contents. The most important point for the development of glocal cultural contents is a systematic and in-depth analysis of other culture. India is a complex and multicultural country compared with Korea which is a nation-state. Therefore, this paper is intended as an understanding about India appropriately and suggestion for a strategy to enter cultural industry in India. As the purpose of this paper is concerned, we will take a close look at 9 Indian culture codes which can be classified into three main groups: 1) political, social and cultural codes 2) economic codes 3) cultural contents codes. Firstly, political, social and cultural codes are i) consistent democracy and saving common people, ii) authoritarianism which appears an innate respect for authority of India, iii) Collective-individualism which represents collectivist and individualistic tendency, iv) life-religion, v) carpe diem. Secondly, economic culture codes are vi) 1.2billion Indian people's God which represents money and vii) practical purchase which stands for a reasonable choice of buying products. Lastly, viii) Masala movie and ix) happy ending that is the most popular theme of Masala movies are explained in the context of cultural content codes. In conclusion, 3 interesting cases , , will be examined in detail. From what has been discussed above, we suggest oversea expansion strategy based on these case studies. Eventually, what is important is to understand what Indian society is, how Indian society works and what contents Indian prefers.