• 대한전자공학회논문지SD
• /
• 제46권4호
• /
• pp.53-63
• /
• 2009

본 논문에서는 IEEE 802.11n 표준과 같은 근거리 무선통신망 응용을 위한 10비트 100MS/s 27.2mW $0.8mm^2$ 0.18um CMOS ADC를 제안한다. 제안하는 ADC는 고속 동작에 적합한 3단 파이프라인 구조를 기반으로 제작되었으며 각단에 공통적으로 사용되는 증폭기, 프리앰프 및 저항열을 최대한 효율적으로 공유함으로써 전력 소모 및 면적을 최소화하였다. 첫 번째 MDAC과 두 번째 MDAC에는 스위치 저항과 메모리 효과가 없는 증폭기 공유기법을 사용하였고, 세 개의 4비트 flash ADC에는 단 하나의 저항열만을 사용하는 동시에 두 번째 flash ADC와 세 번째 flash ADC에는 프리앰프를 공유하여 전력 소모와 면적을 최소화하였다. 보간 기법을 사용하여 요구되는 프리앰프의 수를 반으로 줄였으며, 프리앰프의 공유 및 보간 기법으로 인한 영향을 최소화하기 위해 낮은 킥-백 잡음을 갖는 비교기를 추가로 제안하였다. 제안하는 시제품 ADC는 0.18um 1P6M CMOS 공정으로 제작되었으며, 측정된 DNL 및 INL은 10비트 해상도에서 각각 최대 0.83LSB와 1.52LSB의 수준을 보이며, 동적 성능으로는 100MS/s의 동작 속도에서 각각 52.1dB의 SNDR과 67.6dB의 SFDR을 갖는다. 시제품 ADC의 칩 면적은 $0.8mm^2$이며 전력 소모는 1.8V 전원 전압을 인가하였을 때 100MS/s에서 27.2mW이다.

• 농업과학연구
• /
• 제14권2호
• /
• pp.213-231
• /
• 1987

상수리나무와 굴참나무의 잎과 절간조직(節間組織)을 MS 및 GD배지(培地)에 식물생장조절물질(植物生長調節物質)로 NAA와 BAP, NAA와 kinetin, 2,4-D와 BAP, 2,4-D와 kinetin을 몇가지 농도(濃度)로 첨가하여 callus 배양(培養)한 결과(結果) 다음과 같은 결과(結果)를 얻을 수 있었다. 1. NAA와 BAP를 GD배지(培地)에 첨가하여 배양(培養)한 것이 callus 형성율(形成率)이 양호(良好)할 뿐만 아니라 callus 생장(生長)도 좋았으며, MS배지(培地)에서는 처리농도(處理濃度)에 따라 많은 차이(差異)가 나타났다. 뿌리는 NAA와 BAP의 농도 비(比)가 10~100배(倍)일 때 형성(形成)되었다. 2. NAA와 kinetin 조합(組合)에서도 GD배지(培地)에서 callus 형성율(形成率)이 100%로 좋았으며, callus 생장(生長)도 저농도(低濃度)의 NAA와 kinetin을 처리(處理)한 것을 제외(除外)하고는 대체적으로 양호(良好)하였다. 뿌리는 주(主)로 잎조직을 GD배지(培地)에 배양(培養)하였을 때 발생(發生)되었다. 3. 2,4-D와 BAP조합(組合)에서도 GD배지(培地)에서 callus가 100% 형성(形成)되었으며, callus의 생장(生長)은 MS 및 GD배지(培地)에서 모두 양호하였고, 특히 절간조직(節間組織)을 MS배지(培地)에 2,4-D $10{\mu}M$, BAP $1.0{\mu}M$과 2,4-D $10{\mu}M$, BAP $0.1{\mu}M$ 첨가하여 배양(培養)하였을 때 직경(直徑) 22mm이상(以上)으로 가장 왕성(旺盛)한 생장(生長)을 보여주었다. 4. 2,4-D와 kinetin에서도 MS배지(培地)에 비하여 GD배지(培地)에서 callus 형성율(形成率)이 높았으며 callus의 생장(生長)은 MS 및 GD배지(培地)에서 모두 양호(良好)하였다. 이상(以上)의 결과(結果)를 종합해 보면 callus 형성(形成)은 GD배지(培地)에서 생장조절물질(生長調節物質)의 종류(種類) 및 농도(濃度)에 관계없이 양호(良好)하였으며, callus의 생장(生長)은 2,4-D와 BAP 및 2,4-D와 kinetin 조합(組合)이 좋았으며, MS배지(培地)에 비(比)하여 GD배지(培地)에서 생장(生長)이 양호(良好)하였다. callus로부터 뿌리분화(分化)는 NAA와 BAP 및 NAA와 kinetin을 첨가한 배지(培地)에서만 나타났다.

• ETRI Journal
• /
• 제32권2호
• /
• pp.255-264
• /
• 2010

Interference scenarios and methodologies between a terrestrial mobile service (MS) system and mobile-satellite service (MSS) system in a co-channel environment are established. Taking into account a practical deployment situation for both systems, we perform computational simulation of interference in terms of carrier-to-interference ratio (C/I) and interference-to-noise ratio (I/N) to evaluate the cofrequency interference from an MS system into an MSS system, and from an MSS system into an MS system, respectively. The methodology and results can be used as a guide when planning the deployment of MSS and MS systems with no unacceptable interference impact between them.

• 센서학회지
• /
• 제14권1호
• /
• pp.1-6
• /
• 2005

This paper describes a novel concept of a chemically sensitive scanning force microscope (CS-SFM). It consists of the conventional SFM and the time-of-flight mass spectrometer (TOF-MS). A switchable cantilever (SC) fabricated by the micromachining technology combines each advantage of two completely different systems, SFM and TOF-MS. The CS-SFM offers to produce both images of topography and chemical information simultaneously. First we employed a rotatable tip holder based on 4 piezotube actuators for demonstration of the possibility of the CS-SFM concept. Second the CS-SFM concept is optimized with the micromachining technology. The micromachined SC with an integrated bimorph actuator and a piezoresistive strain sensor provides a reasonable switching speed of ${\sim}10$ ms which is very attractive for the CS-SFM application. The SC is currently being integrated in an ultra-high-vacuum system to perform various experiments.

• Mass Spectrometry Letters
• /
• 제2권4호
• /
• pp.88-91
• /
• 2011

The pharmacokinetic properties of S-amlodipine were studied using racemic amlodipine and single S-enantiomer (SK310) administration to rats. Plasma levels of the drug were determined using chiral liquid chromatography coupled with tandem mass spectrometry following solid phase extraction. The stereospecific analysis of amlodipine was performed on an ${\alpha}$-acid glycoprotein (AGP) column using a mobile phase comprising 10 mM ammonium acetate (pH 4.0) and propanol at a flow rate of 0.2 mL/min. This method was used to perform a comparative study of the pharmacokinetics of amlodipine and SK310. The results revealed that the pharmacokinetic profile of S-amlodipine after the administration of SK310 was comparable to that following the administration of the racemic mixture.

• Mass Spectrometry Letters
• /
• 제6권2호
• /
• pp.43-47
• /
• 2015

Detection of mefenamic acid (M, non-steroidal anti-inflammatory drug, NSAIDs) and its metallodrug was investigated using electrospray ionization mass spectrometry (ESI-MS) and fluorescence spectroscopy. ESI-MS data (500 µL, 1×10-3 M) revealed high detection sensitivity for the drug and metallodrug. ESI-MS spectra revealed peaks at 242, 580, and 777 Da corresponding to [M+H]+, [63Cu(M-H)2(H2O)2+H]+, and [56Fe(M-H)3+H]+, respectively. The metal:mefenamic ratios of ESIMS spectra are in complete agreement with the fluorescence spectroscopy results (1:2 for Cu(II) and 1:3 for Fe(III)). ESI is a soft ionization technique that can be used on labile metallo-mefenamic acids and is promising for the detection of these species in environmental samples and biological fluids.

• Ocean and Polar Research
• /
• 제25권1호
• /
• pp.53-62
• /
• 2003

Inductively coupled plasma mass spectrometry (ICP-MS) is useful instrument for determining abundance of rare earth elements, due to very low detection limits and rapid data acquisition. In this article, two methods are used for decomposition of alkaline rocks; close vessel acid digestion and $Na_2Co_3$ fusion. The two analytical results show good agreements. Considering total dissolved solids and detection limits, the most adequate dilution factor is 5,000 times. Polyatomic ion interferences during analysis can give rise to Inaccuracies. After correction from oxide and hydroxide interference, the analytical result show 20-30% decrease for Gd and Tm, 10-20% decrease for Tb and Er. In comparing the analytical results from KORDI with other institutes, most rare earth elements abundance show good agreements except Lu.

• Archives of Plastic Surgery
• /
• 제39권1호
• /
• pp.3-10
• /
• 2012

The free muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) and deep inferior epigastric perforator (DIEP) flaps involve transferring skin and subcutaneous tissue from the lower abdominal area and have many features that make them well suited for breast reconstruction. The robust blood supply of the free flap reduces the risk of fat necrosis and also enables aggressive shaping of the flap for breast reconstruction to optimize the aesthetic outcome. In addition, the free MS-TRAM flap and DIEP flap require minimal donor-site sacrifice in most cases. With proper patient selection and safe surgical technique, the free MS-TRAM flap and DIEP flap can transfer the lower abdominal skin and subcutaneous tissue to provide an aesthetically pleasing breast reconstruction with minimal donor-site morbidity.

• 분석과학
• /
• 제8권4호
• /
• pp.405-410
• /
• 1995

A study on elemental speciation of trace metals in lake water (Lake Biwa in Japan) has been carried out by a size exclusion chromatography (SEC) / inductively coupled plasma mass spectrometry (ICP-MS) system. Before analysis, the water sample was preconcentrated with a ultrafiltration technique, where the large molecules with molecular weight larger than 10,000 were concentrated. Then the preconcentrated water samples (500-1000 fold) were analyzed by a SEC/ICP-MS system. Most trace metals were found at the UV absorption peaks corresponding to the molecular weights of ca. 300,000 and 10,000-50,000, where trace metals were on-line detected by ICP-MS. The results suggest that many of trace metals exist as the large organic molecules-metal complexes in natural water.

• Journal of Korean Vacuum Science & Technology
• /
• 제2권2호
• /
• pp.133-138
• /
• 1998

To enhance the ionization level of I-PVD and reduce the coil voltage two approaches were tried and as a diagnostic, optical emission spectroscopy and impedance analysis of the plasma was done with a range of Ar pressures and RF power along with XRD analysis of deposited Ag films. RF sputtering power was pulsed with various on/off time scales to recover the ICP quenched by sputtered metals. This in average enhances the ionization of the sputtered atoms with 10 ms/10 ms and 100 ms/100ms pulse on/off time duration and gives higher (200) preferred orientation over (111) in deposited Ag films. Secondly, Small axial B field about 8G remarkably reduced RF coil sputtering and showed scaled relationship between RF power and magnetic field strength for optimal process condition. From OES of Ar0 and Ar+, wave-like dispersion structure appeared and reduced the coil voltage about 20% at very weak field strength of 8G. This should be studied further to have nay relation with low mode helicon wave launching.