• 디지털융복합연구
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• 제16권9호
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• pp.413-419
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• 2018

스마트폰은 현대사회에서 꼭 필요한 통신수단이 되었고 이미 인류의 일상생활에 융합되었다. 만약에 미니 헤드 마운트 표시 장치(HMD)를 활용하여 증강현실 기술로 통신 중인 양쪽 상대방의 용모, 표정, 동작 등의 요소가 통화 환경에 들어오면 사용하는 사람에게 직관적이고 특별한 느낌을 준다. 그리고 이 방식으로 시각의 한계성을 넘어설 수 있으므로 미래 시각예술 영역의 크게 발전을 촉진할 수 있어서 이런 기술적인 문제에 관한 연구의 의미가 있다. 본 논문은 효과적인 AR 영상통화 구현 방법에 대한 현재 사용되는 기술 중 몇 가지를 융복합하여 실현 가능한 두 가지 가설방안을 세우고 분석과 비교하여 두 가지 가설방안의 문제점을 발견한다. 그리고 문제점에 대한 해결 가능한 디자인 방안을 꺼낸다. 또 사례연구의 방식으로 실제 사례를 제출하여 두 가지 가설 방안은 미래에 실현 가능하다는 결론을 검증한다. 이러한 기술들은 우리의 일상에 더욱 재미요소와 편리함을 제공할 것이라 예상된다. AR 영상통화를 순조롭게 구현하는 것은 예견할 수 있고 나중에 무한한 발전 가능성이 있다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권5호
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• pp.213-217
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• 2005

In this paper, we introduced a LIF measurement method and summarized the theoretical side. When an altered wavelength of laser and electric power, lamp applied electric power, we measured the relative density of the metastable state in mercury after observing a laser induced fluorescence signal of 404.8nm and 546.2nm, and confirmed the horizontal distribution of plasma density in the discharge lamp. Due to this generation, the extinction of atoms in a metastable state occurred through collision, ionization, and excitation between plasma particles. The density and distribution of the metastable state depended on the energy and density of plasma particles, intensely This highlights the importance of measuring density distribution in plasma electric discharge mechanism study The results confirmed the resonance phenomenon regarding the energy level of atoms along a wavelength change, and also confirmed that the largest fluorescent signal in 436nm, and that the density of atoms in 546.2nm ($6^3S_1 {\to} 6^3P_2$ ) were larger than 404.8nm ($6^3S_1 {\to} 6^3P_1$). According to the increase of lamp applied electric power, plasma density increased, too. When increased with laser electric power, the LIF signal reached a saturation state in more than 2.6mJ. When partial plasma density distribution along a horizontal axis was measured using the laser induced fluorescence method, the density decreased by recombination away from the center.

• 생명과학회지
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• 제8권1호
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• pp.8-13
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• 1998

옥수수의 미토콘드리아 변이체(NGS2)는 전자전달계 내의 NADH dehydrogenase를 구성하고 있는 subunit 4와 7 유전자의 재조합에 의해서 생성된 변이체이다. 이들의 변이체들은 식물의 성장과 발육에 절대적인 영양을 미치며, 또한 기내에서의 callus line들의 생성과 발달에도 상당한 영향을 미친다. 이들의 미토콘드리아 mutant 들은 3개의 primer를 사용하는 PCR 방법에 의해서 쉽게 선별이 가능하며, 세포 내의 키토콘드리아 변이 정도를 간접적으로 추측케 하며, 체시포 분열시 세포질 내의 기관들이 random으로 분리되는 현상을 간법적으로 알 수 있다. NGS2 mutant들에서 유기된callus line들은 식물체 재문화에도 영향을 미쳐 murant 미토콘드리아가 많은 call line들에슨 실질적인 부정 줄기의 유기를 방해하는 것으로 사료된다. 결론적으로 NADH-dehydrogenase는 식물체가 재분화 또는 성장하는데 있엇 필요한 요소라고 생각된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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• pp.27-32
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• 2006

In this paper, we introduced a LIF measurement method and summarized the theoretical side. When an altered wavelength of laser and electric power, lamp applied electric power, we measured the relative density of the metastable state in mercury after observing a laser induced fluorescence signal of 404.8nm and 546.2nm, and confirmed the horizontal distribution of plasma density in the discharge lamp. Due to this generation, the extinction of atoms in a metastable state occurred through collision, ionization, and excitation between plasma particles. The density and distribution of the metastable state depended on the energy and density of plasma particles, intensely. This highlights the importance of measuring density distribution in plasma electric discharge mechanism study. The results confirmed the resonance phenomenon regarding the energy level of atoms along a wavelength change, and also confirmed that the largest fluorcscent signal in 436nm, and that the density of atoms in 546.2nm ($6^3S_1{\rightarrow}6^3P_2$) were larger than 404.8nm ($6^3S_1{\rightarrow}6^3P_2$). According to the increase of lamp applied electric power, plasma density increased, too. When increased with laser electric power, the LIF signal reached a saturation state in more than 2.6mJ. When partial plasma density distribution along a horizontal axis was measured using the laser induced fluorescence method, the density decreased by recombination away from the center.

• 신재생에너지
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• 제18권1호
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• pp.29-34
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• 2022

The most prevalent cause of solar cell efficiency loss is reduced recombination at the metal electrode and silicon junction. To boost efficiency, a a SiO_X/poly-Si passivating interface is being developed. Poly-Si for passivating contact is formed by various deposition methods (sputtering, PECVD, LPCVD, HWCVD) where the ploy-Si characterization depends on the deposition method. The sputtering process forms a dense Si film at a low deposition rate of 2.6 nm/min and develops a low passivation characteristic of 690 mV. The PECVD process offers a deposition rate of 28 nm/min with satisfactory passivation characteristics. The LPCVD process is the slowest with a deposition rate of 1.4 nm/min, and can prevent blistering if deposited at high temperatures. The HWCVD process has the fastest deposition rate at 150 nm/min with excellent passivation characteristics. However, the uniformity of the deposited film decreases as the area increases. Also, the best passivation characteristics are obtained at high doping. Thus, it is necessary to optimize the doping process depending on the deposition method.

• 한국정보과학회논문지:시스템및이론
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• 제34권8호
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• pp.327-336
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• 2007

비용 효과가 좋은 디지털 시스템을 설계하기 위하여, 트랜지스터 수준부터 RTL 수준까지 최적화를 위한 다양한 설계 방법이 연구되어 왔다. 가산기는 디지털 시스템에서 가장 기본적인 산술연산을 수행하는 필수 회로로서, 전체 시스템의 성능에 영향을 줄 수 있다. 본 논문에서는 최적의 가산기를 설계하기 위하여 상위수준에서 연구하였다. 결과로 혼합 가산기 구조를 제안하고 이를 정수 선형 프로그래밍(ILP: integer liner programming)을 이용해 수학적으로 모델링한다. 혼합 가산기 구조는 다양한 캐리 전달 방식을 가진 가산기 블록을 선형적으로 연결한 구조로서, 사용된 가산기 블록의 종류와 개수에 따라 다양한 가산기 조합이 발생한다. 이러한 조합에 의해 확장된 가산기의 설계공간을 탐색함으로써, 단일 타입의 가산기만을 고려한 것보다 나은 최적의 가산기를 설계할 수 있다. 제안한 혼합 가산기 구조와 ILP를 이용한 최적화 기법은 연산시간과 회로면적 등의 특성이 다른 가산기 IP(intellectual property)들을 비트 수준에서 재합성하기 때문에, 보다 미세한 수준에서 최적화를 수행할 수 있다.

• 한국분말재료학회지
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• 제25권3호
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• pp.257-262
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• 2018

The coupling of two semiconducting materials is an efficient method to improve photocatalytic activity via the suppression of recombination of electron-hole pairs. In particular, the coupling between two different phases of $TiO_2$, i.e., anatase and rutile, is particularly attractive for photocatalytic activity improvement of rutile $TiO_2$ because these coupled $TiO_2$ powders can retain the benefits of $TiO_2$, one of the best photocatalysts. In this study, anatase $TiO_2$ nanoparticles are synthesized and coupled on the surface of rutile $TiO_2$ powders using a microemulsion method and heat treatment. Triton X-100, as a surfactant, is used to suppress the aggregation of anatase $TiO_2$ nanoparticles and disperse anatase $TiO_2$ nanoparticles uniformly on the surface of rutile $TiO_2$ powders. Rutile $TiO_2$ powders coupled with anatase $TiO_2$ nanoparticles are successfully prepared. Additionally, we compare the photocatalytic activity of these rutile-anatase coupled $TiO_2$ powders under ultraviolet (UV) light and demonstrate that the reason for the improvement of photocatalytic activity is microstructural.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권1호
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• pp.35-40
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• 2015

In this study, an n-ZnO/p-Si heterojunction diode with embedded Ag nanoparticles was fabricated to investigate the possible improvement of light trapping via the surface plasmon resonance effect for solar cell applications. The Ag nanoparticles were fabricated by the physical sputtering method. The acquired current-voltage curves and optical absorption spectra demonstrated that the application of Ag nanoparticles in the n-ZnO/p-Si interface increased the photo current, particularly in specific wavelength regions. The results indicate that the enhancement of the photo current was caused by the surface plasmon resonance effect generated by the Ag nanoparticles. In addition, minority carrier lifetime measurements showed that the recombination losses caused by the Ag nanoparticles were negligible. These results suggest that the embedding of Ag nanoparticles is a powerful method to improve the performance of n-ZnO/p-Si heterojunction solar cells.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.45-53
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• 2010

We have developed an efficient and precise method for genome manipulations in Bacillus subtilis that allows rapid alteration of a gene sequence or multiple gene sequences without altering the chromosome in any other way. In our approach, the Escherichia coli toxin gene mazF, which was used as a counter-selectable marker, was placed under the control of a xylose-inducible expression system and associated with an antibiotic resistance gene to create a "mazF-cassette". A polymerase chain reaction (PCR)-generated fragment, consisting of two homology regions joined to the mazF-cassette, was integrated into the chromosome at the target locus by homologous recombination, using positive selection for antibiotic resistance. Then, the excision of the mazF-cassette from the chromosome by a single-crossover event between two short directly repeated (DR) sequences, included in the design of the PCR products, was achieved by counter-selection of mazF. We used this method efficiently and precisely to deliver a point mutation, to inactivate a specific gene, to delete a large genomic region, and to generate the in-frame deletion with minimal polar effects in the same background.

• 한국태양에너지학회 논문집
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• 제35권5호
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• pp.57-65
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• 2015

The Potential Induced Degradation(PID) in PV module mainly affected by various performance conditions such as a potential difference between solar cell and frame, ambient temperature and relative humidity. The positive charges as sodium ions in front glass reach solar cell in module by a potential difference and are accumulated in the solar cell. The ions accelerate the recombination of generation electrons within solar cell under illumination, which reduces the entire output of module. Recently, it was generally known that PID generation is suppressed by controlling the thickness of SiNx AR coating layer on solar cell or using Sodium-free glass and high resistivity encapsulant. However, recovery effects for module with PID are required, because those methods permanently prevent generating PID of module. PID recovery method that voltage reversely applies between solar cell and frame contract to PID generation begins to receive attention. In this paper, PID recovery tests by using voltage under various outdoor conditions as humidity, temperature, voltage are conducted to effectively mitigate PID in module. We confirm that this recovery method perfectly eliminates PID of solar cell according to repeative PID generation and recovery as well as the applied voltage of three factors mainly affect PID recovery.