• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1277-1281
• /
• 2007

A Nano-tip as a cold field emitter for inducing a field emission current has manufactured in many ways. In the paper, the electrochemical etching method is used. Thus, in order to optimize the final shape as the field emitter, the reliable fabrication system for electrochemical etching was constructed. In addition, the effective parameters such as applied voltage, submerged length, meniscus height, electrolyte concentration and environmental condition(vibration, humidity, cut-off time) have investigated in detail. By controlling the parameters, reliable tungsten tip for field emitter was fabricated. And the fabricated tungsten tip was evaluated optically. Finally, the very sharp apex of the tungsten tip was observed with scanning electron microscope.

• Journal of Photoscience
• /
• v.7 no.3
• /
• pp.103-108
• /
• 2000

We have evaluated a new mutagenesis strategy called random insertional mutagenesis with subtracted cDNA fragments. The cDNAs from long day Arabidopsis plants were subtracted by cDNAs from short day plants using PCR based cDNA subtraction. The subtracted cDNAs were inserted between 35S promoter and 3'-NOS terminator regardless of orientation. When the cDNA library was used for the random insertion into Arabidopsis genome by Agrobacterium-mediated transformation, approximately 15% of transformants showed abnormal development in leaf, floral organ, shoot apex. When 20 mutants were analyzed, 12 mutants showed single cDNA fragment insertion and 8 mutants showed more than 2 transgene insertions. Only two mutants among 12 mutants that have single cDNA insert showed consistent phenotype at T2 generation, suggesting the genetic instability of the mutants.

• ALGAE
• /
• v.20 no.4
• /
• pp.279-293
• /
• 2005

Two new species of Martensia (Delesseriaceae, Rhodophyta) are described from Jeju Island, Korea. Martensia palmata sp. nov. is characterized by the following traits: more or less linearly elongated lobes arising from the distal margin of the flabellate membranous section; intact latticework with coarse and loose mesh; numerous spine-like projections on the leading margin of the latticework; tetrasporangia produced in sori along the entire blade; spermatangia borne in sori on the membranous section and the longitudinal lamellae of the latticework; and cystocarps borne on the margins of the membranous section. Martensia projecta sp. nov. has the following characteristics: subdichotomously furcated blades, with terminal segments slightly attenuated toward the apex; blades with uneven surfaces; basal parts with a multi-layered parenchymatous construction; small and poorlydefined latticework; tetrasporangia and spermatangia produced in sori on the membranous section; and cystocarps borne on the marginal surfaces of the blades. The existence of M. projecta sp. nov. supports the proposal that the genus Opephyllum Schmitz in Schmitz et Hauptfleisch should be assigned to the genus Martensia.

• Journal of Chest Surgery
• /
• v.12 no.4
• /
• pp.365-370
• /
• 1979

The first Mitral Commissurotomy was performed for tight mitral stenosis on March 1957. The patient was at that time 22-year-old male, student. The longest follow 9p for 22 years and 8 months has been obtained. During the follow up period, late deterioration due to restenosis developed 4 years after initial good result and reoperation was succeeded by transventricular Mitral Valvotomy with Tubb`s ilator on April 1964. The possible cause of restenosis was attributed to recurrent rheumatic activity. After more than 13 years long-good life following 2nd operation, Endocarditis such as episode of high fever & chill intermittently followed by mild fever and night sweat, I t. tibial artery embolization and rupture of aortic cusp. At present, patient complained of no subjective symptom, enjoying ordinary life {NYHA II]. Blood pressure has been 110/50-60 mmHg, trivial diastolic murmur at apex and moderate degree of mechanical murmur on diastole at Erb`s rea. Neither signs of RVH for mitral stenosis nor sign of LVH. ST-T change for aortic regurgitation appeared yet during last 2 yrs. The patient`s are for prevention of Rheumatic activity and development of endocarditis is important for obtaining the better long-term result.

• Journal of Chest Surgery
• /
• v.48 no.5
• /
• pp.355-358
• /
• 2015

Isolated congenital left ventricular diverticulum is a rare cardiac malformation. Here, we report the case of a 33-year-old woman who had suffered from recurrent transient ischemic attacks for 6 years. Preoperative cardiac magnetic resonance imaging and computed tomography angiography revealed a diverticulum near the apex. The diverticulum was successfully obliterated by cardiopulmonary bypass. We suggest that isolated congenital left ventricular diverticulum can be easily corrected with a low surgical risk by patch repair and plication techniques.

• Journal of Biomedical Engineering Research
• /
• v.36 no.5
• /
• pp.198-203
• /
• 2015

The purpose of the study is to examine the effects of pacemaker location on cardiac pumping efficacy theoretically. We used a three-dimensional finite element cardiac electromechanical model of canine ventricles with models of the circulatory system. Electrical activation time for normal sinus rhythm and artificial pacing in apex, left ventricular free wall, and right ventricular free wall were obtained from electrophysiological model. We applied the electrical activation time maps to the mechanical contraction model and obtained cardiac mechanical responses such as myocardial contractile ATP consumption, stroke work, stroke volume, ejection fraction, and etc. Among three artificial pacing methods, left ventricle pacing showed best performance in ventricular pumping efficacy.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.26 no.2
• /
• pp.13-46
• /
• 2001

SDP (Semidefinite Programming), as a sort of “cone-LP”, optimizes a linear function over the intersection of an affine space and a cone that has the origin as its apex. SDP, however, has been developed in the process of searching for better solution methods for NP-hard combinatorial optimization problems. We surveyed the basic theories necessary to understand SDP researches. First, We examined SDP duality, comparing it to LP duality, which is essential for the interior point method, Second, we showed that SDP can be optimized from an interior solution in polynomial time with a desired error limit. finally, we summarized several research papers that showed SDP can improve solution methods for some combinatorial optimization problems, and explained why SDP has become one of the most important research topics in optimization. We tried to integrate SDP theories. relatively diverse and complicated. to survey research papers with our own perspective, and thus to help researcher to pursue their SDP researches in depth.

• Journal of Biomedical Engineering Research
• /
• v.15 no.1
• /
• pp.63-70
• /
• 1994

A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors'reporting results. Input int'ormation was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and Analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed id'ormation can be transferred for patient diagnosis through LAN (local area network).

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.7
• /
• pp.1219-1225
• /
• 2001

In this Paper we describe the design of synchronization algorithms for burst QPSK receiver, which are applicable to BWLL uplink. The demodulator consists of digital down converter, matched filter and synchronization circuits. For symbol timing recovery we ufo Gardner algorithm. And we use forth power method and decision directed method for carrier frequency recovery and phase recovery, respectively. For the sake of performance analysis, we compare simulation results with the board implemented by FPGA which is APEX20KE series chip for Alter. The performance results show it works quite well up to the condition that a frequency offset equal to 4.7% of symbol rate.

• Proceedings of the KIEE Conference
• /
• 2005.05a
• /
• pp.137-140
• /
• 2005

The electronic dispenser is composed of electronic part and mechanical part. Electronic part is consisted of input keypad, micro-controller, display module, and pump module. In this paper we designed micro-controller for electronic part. The micro-controller controls display module and pump module. The display module is composed by LCD device, and the pump module is composed by motor device. The micro-controller for an electronic dispenser is designed by VHDL. We used WX12864APl for the LCD device and SPS20 for the stepping motor. Also, the micro-controller is designed by Altera Quartus tool and verified with Agent 2000 Design-kit using APEX20K Device. In this paper, we present possibility to adopt of biotechnology field through designing of one-chip controller for an electronic dispenser.