• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.16 no.6
• /
• pp.465-471
• /
• 2023

This paper proposes a comparator structure that improves the noise and output delay of a single-slope ADC(SS-ADC) used in CMOS Image Sensor (CIS). To improve the noise and delay characteristics of the output, a comparator structure using the miller effect is designed by inserting a capacitor between the output node of the first stage and the output node of the second stage of the comparator. The proposed comparator structure improves the noise, delay of the output, and layout area by using a small capacitor. The CDS counter used in the single slop ADC is designed using a T-filp flop and bitwise inversion circuit, which improves power consumption and speed. The single-slope ADC also performs dual CDS, which combines analog correlated double sampling (CDS) and digital CDS. By performing dual CDS, image quality is improved by reducing fixed pattern noise (FPN), reset noise, and ADC error. The single-slope ADC with the proposed comparator structure is designed in a 0.18-㎛ CMOS process.

• Digital Contents
• /
• no.6 s.49
• /
• pp.60-65
• /
• 1997

제18회 내셔널 온라인 미팅과 DB/EXPO'97 전시회는 전세계 데이터베이스 관련 업체들이 참여하는 최대의 데이터베이스 관련 전시회라 할 수 있다. 온라인 서비스, CD-롬 타이틀, 인터넷, 인트라넷, 클라이언트 서버 환경 등 다양한 환경에서 이용할 수 있는 데이터베이스를 선보인 전시회였다.

• 한국해양학회지
• /
• v.18 no.2
• /
• pp.180-184
• /
• 1983

Sediments were collected from eight stations in JJJJinhae Bay and heavy metals were fractionated into the adsoibed reducible, oxidizable and residual fractions. Cd, Cu, Pb and Zn in each fraction were determined by atomic absorption spectriphotmetry. Cd was shown to be mainly in the adsorbed form, Cu in the oxidizable and resedual fractions, and Pb and Zn mainly in the seducible fractions. The total concentrations of Cu, Pb and Zn in sediments decreased gradually with increasing distance from the heak of the bay, and the relationship of linear segression was obtained.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.898-901
• /
• 2001

This study was carried out to research on the heavy metal contents of domestic and imported medicinal herbs. The heavy metals contents in 116 samples of 51 types of medicinal herbs were measured by using a modified Monier-Williams, mercury analyzer and inductively coupled plasma spectrometer(ICP). The heavy metal contents of medicinal herbs were as follows; Hg: 0.010(domestic: 0.010, imported: 0.010), Pb: 0.380(0.311, 0.449), Cd: 0.080(0.101, 0.059), As: 2.085(1.845, 2.324), Mn: 31.564(33.844, 29.283), Zn: 15.436(18.703, 12.168), Cu: 3.406(3.374, 3.437), Fe: 134.944(108.327, 161.561) by ppm unit. The measured values of Pb and Cd of domestic and imported medicinal herbs showed lower levels than the recommended levels of those in medicinal herbs by WHO/PHARM (Pb: not more than 10 ppm, Cd: not more than 0.3 ppm). Finally, this results will be used as a basic data for the future legislation on the regulation and control of heavy metal contents of medicinal herbs.

• International Commerce and Information Review
• /
• v.2 no.2
• /
• pp.97-110
• /
• 2000

1990년대 중반 인터넷이 상업용으로 발달하면서 전자상거래의 경제적 효과에 관한 연구가 활발히 진행되고 있다. 인터넷은 자유로운 시장진입을 가능하게 하고 제품 및 가격에 대한 완전한 정보를 공유하게 함으로써 경제적 비효율성을 제거할 수 있다. 그러나 한편으로 인터넷상의 검색비용 등이 실세계에서의 비용과 비교할 경우 그 차이가 매우 작을 수 있다는 주장도 있다. 인터넷으로 판매하는 상품들의 가격이 전통상점에서의 판매가격보다 낮은 지의 여부는 결국 실증문제로 귀착된다. 본 연구는 한국에서 서적과 음반CD에 대해 인터넷상점과 전통상점에 의해 부과되고 있는 실제가격들을 비교함으로써 이러한 질문에 대한 해결을 시도하고자 한다. 이들 두 제품은 한국은 물론 해외에서도 전자상거래로 가장 빈번히 거래되고 있는데다 제품의 표준화가 여타제품에 비해 비교적 잘되어 있는 제품들이다. 본 연구는 실증분석을 위해 2000년 9월 18~30일 동안 조사원들에 의해 실제 매장과 인터넷사이트에서 수집된 가격관찰치를 집계하고 이들 자료에 대한 통계적 검정을 시도하였다.

• Journal of Environmental Science International
• /
• v.26 no.3
• /
• pp.303-309
• /
• 2017

Aeration with low energy micro-bubble generation and $UV/H_2O_2$ processes was introduced to verify the possibility of oxidation treatment for acid mine drainage. During 10 hours of aeration with micro-bubbles, Fe and As concentrations were decreased to 18.1 and 61.8%, respectively, while Cu, Cd, Al were kept at influent concentrations. Other heavy metals such as Mn, Cr, Pb, Zn, and Ni concentrations fluctuated due to the repetition of oxidation and release. Twenty days of aeration indicated the oxidation possibility for Cu, Cd, and Al. With the employment of $UV/H_2O_2$ processes, more than 77% of Cu and Fe removed, whereas slightly more than 30% of Cd and Al removed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2005.04a
• /
• pp.6-8
• /
• 2005

The forest soils of 92 sites in Korea were analyzed to survey heavy metal background levels using aqua regia digestion method and 0.1N HCl extraction method. From these results, the average natural contents of heavy metals were Cd 0.287, Cu 15.26, Pb 18.43, Cr 25.36, Zn 54.27, Ni 17.68mg/kg for aqua regia method, and Cd 0.040, Cu 0.48, Pb 3.06, Cr 0.09, Zn 1.54, Ni 0.27mg/kg for 0.1N HCl extraction method. The range of correlation coefficients between heavy metal contents obtained from two methods(aqua regia and 0.1N HCl) was significant as $0.24{\sim}0.88$, and the correlation coefficients were decreased in order of Cd, Pb, Cu, Ni, Cr, Zn.

• Korean Journal of Crystallography
• /
• v.11 no.3
• /
• pp.133-136
• /
• 2000

The molecular structure of [Cd(L)Cl]Cl·2H₂O(1)(L=3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0/sup 1.18/,0/sup 7.12/]docosane) has been determined by X-ray diffraction. Crystallographic dta for 1: triclinic space group P1, a=9.671(1), b=10.784(1), c=12.679(2)Å, α=112.31(1), β=99.49(1), γ=93.95(1)°, V=1230.6(3)ų, Z=2, R=0.0779. The coordination of the cadmium atom is a distorted square-pyramid with four secondary amines of the macrocycle occupying the basal sites (Cd-N/sub av/=2.300(3)Å) and a terminal chlorine atom at the axial position with a Cd-Cl(1) distance of 2.463(2)Å.

• Journal of the Korean Magnetic Resonance Society
• /
• v.19 no.1
• /
• pp.18-22
• /
• 2015

The structural geometry of $[N(CH_3)_4]_2CdCl_4$ in a hexagonal phase is studied by $^1H$ MAS NMR, $^{13}C$ CP/MAS NMR, and $^{14}N$ NMR. The changes in the chemical shifts for $^{13}C$ and $^{14}N$ in the hexagonal phase are explained by the structural geometry. In addition, the temperature dependencies of the spin-lattice relaxation time in the rotating frame $T_{1{\rho}}$ for $^1H$ MAS NMR and $^{13}C$ CP/MAS NMR are measured.

• Journal of the Semiconductor & Display Technology
• /
• v.16 no.2
• /
• pp.15-18
• /
• 2017

In this study, we have studied the characteristics of the organic photodiode varying due to the blending conditions of the quantum dots (QDs). The active layer of the photodiode was formed with poly (3-hexylthiophene) and phenyl-C61-butyric acid methyl ester, and CdSe QDs with and without ZnS shell were blended in the active layer. The photodiode with CdSe/ZnS QDs showed the highest power conversion efficiency (PCE) and short-circuit current (Jsc). The performance change of the organic photodiode by X-ray irradiation was also measured. Regardless of X-ray irradiation conditions, the photodiode with CdSe/ZnS QDs showed better stability than other cases.