In this paper, we investigate the relationship between control system of Bosch system and that of Delphi system by measuring the high and low voltage waveform, current waveform and fuel injection quantity of D-2 and R- engines. Waveform measurements are used the PICO scope and the CDS tester. The injectors of D-2 and R-engines were tested under no load condition using injector with normal fuel injection quantity, injector with small fuel injection quantity and injector with many fuel injection quantity. The relation between current energy and fuel injection quantity shows that the injector variation rate of D2-engine is much larger than that of R-engine. The injector current energy of the D2-engine was more linear than that of the R-engine, therefore making the system more stable. Although the control system of the D2-engine is a more stable system only in terms of the durability of the internal parts of the injector, the injector of the R-engine has a good response because the current value is large.

This paper investigates the relationship of voltage and current waveform between normal piezo injector and deterioration abnormal piezo injector. The experimental methods using Pico oscilloscope and GDS scan tool are employed to measure current and voltage waveform and fuel pressure of piezo injector. The experiment is carried out during no-load condition. A summary of the important results are as follows. 1) In case of normal injector, the fluctuation of duration time of piezo injector was linearly and regularly decreased with increasing engine speed, but the that of deterioration piezo injector was irregularly decreased with increasing engine speed. 2) In main injection, the peak value of the current waveform of abnormal injector was larger than that of normal injector, the duration time of deteriorated abnormal injector was less than that of normal injector at 800rpm and 1500rpm, but the duration time of deteriorated abnormal injector was larger than that of normal injector at 2000rpm and 3000rpm. This irregularity appears to be caused by the deterioration of the injector.

This paper presents the design and simulation results of a piezo-driven motion stage that employs a novel cross hinge structure that is more efficient and flexible than previous designs. The newly designed motion stage enables close to nanometer-precision motion control with ranges up to 1.6mm. Simulation results show the effectiveness of the novel hinge structures and the performance of the proposed design.

Intracytoplasmic sperm injection (ICSI) is one of the artificial fertilization methods when only a few sperm are available for insemination, and an important tool for the preservation of genetic materials of endangered animal species, especially the male is infertile. Different from other species such as mice and pigs, the conventional ICSI method which uses spiked pipette for injection (Spike-ICSI) is exhibited low success rates in cattle because the bovinesperm head membrane is hard to break during injection procedure. We chose piezo-assisted ICSI (Piezo-ICSI) for the improvement of the injection procedure including sperm head membrane rupture and efficient puncture of the plasma membrane of the oocytes. In this experiment, we compared the efficacy of the bovine ICSI embryo production between the Piezo-ICSI and Spike-ICSI. The second polar body extrusion, pronuclear formation, cleavage and blastocyst formation were evaluated after implementation of two different ICSI techniques. The Piezo-ICSI tended to show comparably higher rates of the second polar body extrusion (41.7%), the pronuclei formation (42.9%) and the two-cell cleavage (41.4%) than Spike-ICSI does (33.3%, 28.6% and 23.5%, respectively) although there is no statistic significance between two groups. In addition, the blastocysts were only obtained from the Piezo-ICSI group (10.3%). Our finding shows that the Piezo-ICSI may be used as an artificial fertilization method in cattle when in vitro fertilization is not applicable.

가진력의 영향을 평가하기 위해 이용되는 압전소자와 물체의 변형량을 분석하기 위해 사용되는 광섬유 센서와 변형 게이지는 각종 시험과 실험에 널리 사용되고 있다. 본 연구에서는 케이블 시스템에서 발생한 손상을 검토하기 위해 압전소자와 광섬유센서를 이용하였다. 케이블 시스템은 압축이나 휨이 발생하지 않고 막구조에서 단지 인장력을 분담한다. 그러나 기존의 안전진단법을 이용하여 케이블 시스템의 손상을 판단하는 것은 전체구조의 특이한 구조거동 등으로 검토하기 어렵다. 인장부재에서 케이블의 풀림과 할렬이 발생하면 진동을 유발하기 때문에 압전소자를 케이블의 손상을 검토하기 위해 이용하였으며, 이를 광섬유 센서를 이용한 실험의 결과와 비교하였다. 본 연구는 인장응력 하에 케이블 시스템의 손상을 검토하는 방법을 제안하기 위한 실험적 연구이다.

Embryonic germ (EG) cells are undifferentiated stem cells isolated from cultured primordial germ cells (PGC). These cells share many characteristics with embryonic stem cells including morphology and pluripotency. Undifferentiated porcine EG cell lines demonstrating capacities of differentiation both in vitro and in vivo have been established. Since EG cells can be cultured indefinitely in an undifferentiated state, whereas somatic cells in primary culture are often unstable and have limited lifespan, EG cells may provide inexhaustible source of karyoplasts in nuclear transfer (NT). In this study the efficiencies of NT using porcine EG and fetal fibroblast cells were compared. Two different techniques were used to perform NT. With conventional NT procedure (Roslin method) involving fusion of donor cells with enucleated oocytes, the rates of development to the blastocyst stage in EG and somatic cell NT were 16.8% (59/351) and 14.5% (98/677), respectively. In piezo-driven microinjection (Honolulu method) of donor nuclei into enucleated oocytes, the rates of blastocyst formation in EG and somatic cell NT were 11.9% (15/126) and 9.4% (9/96), respectively. Regardless of NT methods used in this study, EG cell NT gave rise to comparable rate of blastocyst development to somatic cell NT. Overall, EG cells can be used as karyoplast donor in NT procedure, and embryos can be produced by EG cell NT that may be used as an alternative to conventional somatic cell NT.

This paper presents the development of a 3D printer based piezo-driven vertical micro-positioning stage. The stage consists of two flexure bridge structures which amplify and transfer the horizontal motion of the piezo-element into vertical motion of the end-effector. The stage is fabricated with ABS material using a precision 3D printer. This enables a one-body design eliminating the need for assembly, and significantly increases the freedom in design while shortening fabrication time. The design of the stage was optimized using response surface analysis method. Experimental results are presented which demonstrate 100nm stepping in the vertical out-of-plane direction. The results demonstrate the future possibilities of applying 3D printers and ABS material in fabricating linear driven motion stages.