• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3272-3278
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• 2010

Synthesis and structural characterization of peripherally ferrocene-substituted zinc phthalocyanine (ZnPc-Fc) were carried out for efficient far-red/near-IR performance in dye-sensitized nanostructured $TiO_2$ solar cells. Incorporating ferrocene into phthalocyanine strongly improved the dye solubility in polar organic solvents, and reduced surface aggregation due to the steric effect of bulky ferrocene substituents. The involvement of electron transfer reaction pathways between ferrocene and phthalocyanine in ZnPc-Fc was evidenced by completely quenched fluorescence from S1 state (< 0.08% vs ZnPc). Strong absorption bands at 542 and 682 nm were observed in the transient absorption spectroscopy of ZnPc-Fc in DMSO, which was excited at a 670 nm laser pulse with a 15 ps full width at half maximum. Also, the excited state absorption signals at 450 - 600 and 750 - 850 nm appeared from the formation of charge separated state of phthalocyanine's anion. The lifetime of the charge separate state in ZnPc-Fc was determined to be $170{\pm}8$ ps, which was almost 17 times shorter than that of the ZnPc.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.515-518
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• 2013

We present synthesis of a new kind of organic-inorganic hybrid polymer, poly xylene-hexamethyltrisiloxane hybrid (PXS) by a new synthetic way from o-xylene and 1,1,3,3,5,5-hexamethyltrisiloxane. The merged molecular structure of the two monomeric components for the PXS polymer was confirmed by $^{13}C$- and $^1H$-NMR, and FT-IR. Its optical absorption and emission properties were investigated by UV-vis absorption and photoluminescence (PL) spectroscopy. The PXS exhibits absorption at 265 nm which is the same with the o-xylene but tailing up to nearly 400 nm, which is maybe related the polymeric structure of the PXS. For the PL investigation, the PXS shows red-shift of the peak from 288 nm (o-xylene) to 372 nm in the case of excitation at 265 nm, at which both PXS and o-xylene have sufficiently high absorption for excitation. When 325-nm laser is used for excitation, the PXS shows a broader peak at 395 nm compared to the excitation at 265 nm and the o-xylene shows no luminescence probably due to the lack of absorption at 325 nm.

• Current Optics and Photonics
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• v.3 no.2
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• pp.164-171
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• 2019

Photoluminescence (PL) properties of GaN-based light-emitting diodes (LEDs) were analyzed to study the effects of carrier leakage on the luminescence properties at room temperature. The electrical leakage and PL properties were compared for LEDs showing leakages at forward bias and an LED with an intentional leakage path formed by connecting a parallel resistance of various values. The leakages at the forward bias, which could be observed from the current-voltage characteristics, resulted in an increase in the excitation laser power density for the maximum PL efficiency (ratio of PL intensity to excitation power) as well as a reduction in the PL intensity. The effect of carrier leakages on PL properties was similar to the change in PL properties owing to a reduction of the photovoltage by a reverse current since the direction of the carrier movement under photoexcitation is identical to that of the reverse current. Valid relations between PL properties and electrical properties were observed as the PL properties deteriorated with an increase in the carrier leakage. The results imply that the PL properties of LED chips can be an indicator of the electrical properties of LEDs.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.2
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• pp.204-210
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• 2021

In this paper, we studied a method of wirelessly checking up the POD for captive flight tests which is performed during the development of guided weapons systems. The wireless power transfer module, the power distribution device, and the battery pack were designed to wirelessly power the captive flight test POD, and the communication device was designed to enable wireless communication between the POD and the check-up device. The communication device was designed to enable WiFi, IR communication, and laser diode communication, so that various communication methods could be tested. Through the performance test, it was confirmed that power was stably supplied to the captive flight test POD, and the wireless communication performance was verified by measuring the delay time and error rate. As a result, by using our system the POD check-up for the captive flight test was performed wirelessly and the data of the captive equipment could be obtained effectively.

• Current Optics and Photonics
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• v.7 no.3
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• pp.297-303
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• 2023

In this paper, we demonstrated a high-energy (285 mJ) mid-infrared flashlamp-pumped electro-optically 𝚀-switched Er:YAG master oscillator power amplifier (MOPA) system and comprehensively investigated its temporal, spectral, and spatial characteristics. To increase the output energy, we optimized the delay between the timings at which the flashlamps of the master oscillator and power amplifier were triggered. In addition, the output energy was improved while minimizing thermal effects by cooling the MOPA system to a temperature slightly above the dew point. Consequently, the MOPA structure boosted the output energy without damaging the lithium niobate Pockels cell, which is a crucial element in 𝚀-switching. This design realized pulses with energies up to 0.285 J and pulse durations of approximately 140 ns at a wavelength of 2,936.7 nm. This high-energy mid-IR Er:YAG MOPA system can be used for various scientific, engineering, and military underwater applications.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.803-806
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• 2010

본 논문에서는 스크린을 터치를 하지 않고 또한 스크린의 영역의 크기에 상관없이 제스처를 이용하여 인터랙션이 가능한 제스쳐 인식 모듈을 이용한 대규모 멀티 인터랙티브 디스플레이 시스템을 제안한다. IR laser를 이용하여 인터랙션 영역을 생성하고 band pass filter를 장착한 적외선 카메라를 이용하여 인터랙션 영역 안의 영상을 획득한다. 획득되어진 영상은 제안하는 영상처리모듈을 이용하여 이진화->블랍-라벨링 과정을 거쳐 잡음을 제거한 후 인터랙션 영역 안에서 이루어지는 인터랙션 좌표를 획득한 후 Packet으로 저장한다. 저장 된 Packet은 네트워크 통신 시스템을 이용하여 Server로 보내어지고 Server에서는 메타포분석모듈을 이용하여 분석하여 결과를 메타포이벤트로 저장한 후 콘텐츠에 보낸다. 콘텐츠에서는 받은 메타포이벤트에 따라서 콘텐츠 결과를 보여 줌으로써 스크린을 터치 하지 않아도 터치 인터랙션이 가능하며 스크린 영역에 제한 없이 많은 사용자가 동시에 사용이 가능한 시스템 사용이 가능하도록 한다. 본 시스템은 향후 보다 다양한 인터랙션과 시스템 크기의 확장으로 보다 많은 사용자가 동시에 사용가능하며 다양한 인터랙션을 사용할 수 있는 인식 디바이스로써 활용이 가능하다.

• Clean Technology
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• v.26 no.4
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• pp.293-303
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• 2020

According to the World Health Organization (WHO), air pollution is a typical health hazard, resulting in about 7 million premature deaths each year. Sulfur dioxide (SO2) is one of the major air pollutants, and the combustion process with sulfur-containing fuels generates it. Measuring SO2 generation in large combustion environments in real time and optimizing reduction facilities based on measured values are necessary to reduce the compound's presence. This paper describes the concentration measurement for SO2, a particulate matter precursor, using a wavelength modulation spectroscopy (WMS) of tunable diode laser absorption spectroscopy (TDLAS). This study employed a quantum cascade laser operating at 7.6 ㎛ as a light source. It demonstrated concentration measurement possibility using 64 multi-absorption lines between 7623.7 and 7626.0 nm. The experiments were conducted in a multi-pass cell with a total path length of 28 and 76 m at 1 atm, 296 K. The SO2 concentration was tested in two types: high concentration (1000 to 5000 ppm) and low concentration (10 ppm or less). Additionally, the effect of H2O interference in the atmosphere on the measurement of SO2 was confirmed by N2 purging the laser's path. The detection limit for SO2 was 3 ppm, and results were compared with the electronic chemical sensor and nondispersive infrared (NDIR) sensor.

• Journal of IKEEE
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• v.27 no.1
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• pp.122-126
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• 2023

In this paper, a control system for a complex microbial incubator was proposed. The proposed control system consists of a control unit, a communication unit, a power supply unit, and a control system of the complex microbial incubator. The controller of the complex microbial incubator is designed and manufactured to convert analog signals and digital signals, and control signals of sensors such as displays using LCD panels, water level sensors, temperature sensors, and pH concentration sensors. The water level sensor used is designed and manufactured to enable accurate water level measurement by using the IR laser method with excellent linearity in order to solve the problem that existing water level sensors are difficult to measure due to foreign substances such as bubbles. The temperature sensor is designed and used so that it has high accuracy and no cumulative resistance error by measuring using the thermal resistance principle. The communication unit consists of two LAN ports and one RS-232 port, and is designed and manufactured to transmit signals such as LCD panel, PCT panel, and load cell controller used in the complex microbial incubator to the control unit. The power supply unit is designed and manufactured to supply power by configuring it with three voltage supply terminals such as 24V, 12V and 5V so that the control unit and communication unit can operate smoothly. The control system of the complex microbial incubator uses PLC to control sensor values such as pH concentration sensor, temperature sensor, and water level sensor, and the operation of circulation pump, circulation valve, rotary pump, and inverter load cell used for cultivation. In order to evaluate the performance of the control system of the proposed complex microbial incubator, the result of the experiment conducted by the accredited certification body showed that the range of water level measurement sensitivity was -0.41mm~1.59mm, and the range of change in water temperature was ±0.41℃, which is currently commercially available. It was confirmed that the product operates with better performance than the performance of the products. Therefore, the effectiveness of the control system of the complex microbial incubator proposed in this paper was demonstrated.

• Journal of Conservation Science
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• v.28 no.3
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• pp.217-228
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• 2012

Damage of cultural properties happens variously. Particularly, the surface damage of metal cultural properties exposed outdoors lowers historical and art historical value of artifact by artificial damage such as paint, scribbling containing oily material and so on. Therefore, this study compared dry-ice pellet cleaning with poultice when clearing paint and oily material environment-friendly, harmlessly to humans and without damage of artifact. As the result of experiment, when clearing those (paint and oily material) by poultice, oily paint was cleared, but there were spots of metal surface. Also, Lacquer spray wasn't well cleared, and resin came off the surface of artifact. When clearing those by dry-ice pellet cleaning, oil paint was cleanly cleared without surface damage of artifact according to Stereoscopic microscope observation, color-measurement, FT-IR, SEM analysis. Also, lacquer spray seemed to be cleared with the naked eye, but there were minute particles on surface according to the result of SEM observation. Consequently, we could confirm possibility of dry-ice pellet cleaning substitution.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.81-87
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• 2018

The objective of this article is to provide analytical tools for the scattering of stratum corneum (SC) and to check whether the optical clearing agents (OCAs) could be applied in optics affecting the scattering reduction. Dark field images of tape striped corneocyte separates scattered light of the SC from others in vitro. Several optical clearing agents were tested to reduce the scattering. Physical properties of SC such as water contents, keratin configuration and volume after OCAs treatment were investigated by FT-IR and 3D laser microscope. Several reducing sugars, monomeric sugars, sugar alcohol, and hyaluronic acid, which were used as humectants in cosmetic field, also reduced scattering. However, unlike dehydration in optics, water penetrated into the keratin in SC and scattering was decreased at low concentration of OCAs. In that condition, the volume of corneocyte was increased and stiffness seemed to decrease. The analyzing of tape-stripped SC, showed the change of optical and physical properties of corneocyte by optical clearing agents. The hydration of SC layer by optical clearing agents decreased the scattering of corneocyte and thus improved the skin appearance and moisturizing effect, which are important benefits in the cosmetic field and could provide new possibility to develop skin care study targeting at SC.