• The Korean Journal of Ceramics
• /
• 제3권4호
• /
• pp.257-262
• /
• 1997

Aluminum nitride(AIN) thin films were deposited on SiO$_2$/Si substrates by reactive sputtering for the application of SAW devices. The major deposition parameters such as pressure, nitrogen fraction, rf power, substrate distance were changed to find out the optimal condition for c-axis oriented thin films on an amorphous substrate. The effects of deposition parameters on the crystal structure, residual stress, and growth morphology of thin films were characterized by XRD, SEM, and TEM. The FWHM of (002) rocking curve of the films deposited at the proper condition was lower than 2.2$^{\circ}$(C=0.93$^{\circ}$). Cross-sectional TEM showed that self-aligned structure was developed just after slightly random growth at the initial stage. The frequency characteristics of test device fabricated from AIN thin films confirmed their piezoelectric property and applicability for SAW devices.

• Mycobiology
• /
• 제35권1호
• /
• pp.1-5
• /
• 2007

Three species of the genus Euphoriomyces (Laboulbeniales) were found newly from Korea. E. agathidii (Maire) Tavales was collected from Agathidium sp. (Leiodidae, Coleoptera). The characteristic traits of this species are the distal portion of the primary axis composed of $5{\sim}11$ superposed layers and bearing more or less the elongated appendages. E. cybocephali (Thaxter) Thaxter was collected from Pseudocolenis hilleri Reitter (Leiodidae, Coleoptera). The primary axis of this species composed of $5{\sim}9$ superposed layers is simple, not branched and a single antheridium occurs on the apex of the secondary axis. E. sugiyamae Majewski was collected from Scaphisoma rufum Achard (Scaphidiidae, Coleoptera). This species is very unique in having the antheridia formed as coner cells with lateral necks.

• Journal of Magnetics
• /
• 제2권3호
• /
• pp.105-109
• /
• 1997

The Preisach model neds a density function or Everett function for the hysterisis operator to simulate the hysteresis phenomena. To obtain the function, many experimental data for the first order transition curves are required. However, it needs so much efforts to measure the curves, especially for the hard magnetic materials. By the way, it is well known that the density function has the Gaussian distribution for the interaction axis on the Preisach plane. In this paper, we propose a simple technique to determine the distribution function or Everett function analytically. The initial magnetization curve is used for the distribution of the Everett function for the coercivity axis. A major, minor loop and the initial curve are used to get the Everett function for the interaction axis using the Gaussian distribution function and acceptable results were obtained.

• 한방비만학회지
• /
• 제1권1호
• /
• pp.1-11
• /
• 2001

Obesity is a metabolic disease associated with multiple hormonal abnormalities. Therefore, obesity management aims at balancing these endocrine malfunctions nowadays. Although many studies proved interactions of hormones related with obesity, there are still lots of controversies. Most of these malfunctions are more pronounced in central, visceral obesity than in peripheral obesity. Recently, it is revealed that a central lesion of endocrine malfunction in human visceral obesity is probably related with a hypersensitivity of hypothalamopituitary-adrenal(HPA) axis. Probably associated with this axis, Insulin and cortisol promote lipid accumulation by expressing lipoprotein lipase activity, while sex hormones and growth hormone exert the opposite effects. Also reviewed was thyroid hormone which is closely related with thermogenesis. Serotonin is prescribed as antidepressant and it is applied to some eating disorders. Recently, leptin made in fat deposit also took attentions in terms of regulator of appetite and messenger of sex signal.

• 대한기계학회논문집B
• /
• 제20권8호
• /
• pp.2637-2649
• /
• 1996

Flow characteristics and aerodynamic forces acting on an elliptic cylinder placed in a plane boundary layer were investigated experimentally. Four cylinder models with axis ratio(major axis to minor axis, AR=A/B) of 1, 2, 3, and 4 having the same equivalent diameter were used in this experiment. The Reynolds number based on the equivalent diameter $D_e$(=20mm) was 13,000. In the case of circular cylinder, regular vortex shedding occurs for the cylinder gaps larger than G/B=0.3 and is not almost related to the boundary layer thickness. But, for the elliptic cylinders, the vortex shedding frequency is increased with increasing the gap ratio (G/B) and the axis ratio (AR) of elliptic cylinders. The maximum drag coefficient acting on a circular cylinder is mainly affected by the boundary layer thickness. But, the elliptic cylinders(AR$\geq$2), except for the smaller gap G/B<0.2, show a nearly constant drag coefficient which is much smaller than that of a circular cylinder. The base pressure on the flat plate decreases with increasing the axis ratio(AR) of the elliptic cylinder. In the case of a circular cylinder, the base pressure has the minimum value at the gap ratio G/B=0.4, but it occurs at G/D=2 for elliptic cylinders. The mean velocity of the cylinder wake is quickly recovered at a small cylinder height ratio(H/$\delta$), but the turbulent intensity is rapidly recovered at a large cylinder height ratio(H/$\delta$). The effective wake region in the plane boundary layer is shrinkaged with increasing the axis ratio(AR) of elliptic cylinder. And the drag coefficient and streamwise turbulent intensity of the elliptic cylinder with AR=4 are less than half of those for the circular cylinder(AR=1).

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1254-1258
• /
• 2003

One of the major factors that effect sensor performance is analog noise that added in a sensor signal such as voltage. In multi-axis force sensors, error sources may be classified mainly in two groups. One is structural error due to inaccuracy of sensor body. The other error source is noise signals existing in the sensed information. This paper presents a brief review about the principle of multi-axis force sensors, and then proposes a method that can reduce the effect of noise signal to sensor performance. The method is to convert analog voltage signal to digital numbers near sensor body and then to read these digital signals and conduct signal processing in the computer. By this way, we can eliminate a bad effect of electromagnetic wave emitted from computer and of 60 Hz noise emitted from AC source. The proposed method is investigated through experimental demonstration. The experimental results show that it improves S/N ratio of the sensor about 40 times in our experimental setup.

• 지역사회간호학회지
• /
• 제12권2호
• /
• pp.329-337
• /
• 2001

Purpose: This study was to develop a critical pathway for COPD clients in home health care. Method: Review of literature. Analysis of 10 cases of home health records of COPD clients without other major chronic illness, and Contents validity test Results 1. Vertical axis(l4 activities) physical and mental assessment, family assessment. environment assessment, rights and duties of client, oxygen use and safety, education of disease process and symptom, medication, nutrition and elimination, tests, activities, respiratory exercise, sleeping pattern. consultations and discharge planning. 2. Horizontal axis was set by the number of visits(average number of visits is 6.4) and vertical axis was set with 14 activities and the contents which should have occurred, according to the time frames of the horizontal axis. 3. According to the contents validity test, among the total of 234 items, 176 items showed over 83% agreement and 58 items showed less than 83% agreement. Those items with less than 83% agreements were either deleted or revised. Conclusion this critical pathway is applicable to the home health care of COPD clients to provide quality home nursing care services at lower cost.

• Structural Engineering and Mechanics
• /
• 제51권2호
• /
• pp.215-228
• /
• 2014

Traditional beam connections to the minor axis of a column have relatively low strength and stiffness. A modified detail, using a plate welded between the toes of the column flange - referred to as a toe plate connection - is examined in this paper. The results of an experimental investigation for both flush and extended end-plate connections connected to a 25 mm thick end-plate are presented. The tests are complemented by finite element modelling which compares very well with the test observations. The results show a significant increase in both moment resistance and initial stiffness for this connection detail compared with connections made directly to the column web. This offers the prospect of more optimal solutions taking advantage of partial strength frame design for the minor axis as well as major axis.

• Current Optics and Photonics
• /
• 제6권1호
• /
• pp.44-50
• /
• 2022

An off-axis zone plate is able to focus on a single order while neglecting the zeroth order in a visible imaging system. This allows one to enhance the contrast quality in diffractive images, which is the major advantage of this type of zone plate. However, most previous reflection zone plates are used in focusing X-rays with a small grazing incident angle and are intricately designed with the use of a local grating period. In this study, we suggest the design of an off-axis elliptical zone plate (EZP) that is used to focus a monochromatic light beam with separation between the first and unfocused orders under a large grazing incident angle of 45°. An assumption using the total grating period, which depends on the average and constant grating period, is proposed to calculate the desired distance between the first and zeroth order and to simplify the construction of a novel model off-center EZP. Four diffractive optical elements (DOEs) with different parameters were subsequently fabricated by direct laser lithography and then verified using a performance evaluation system to compare the results from the assumption with the experimental results.

• Applied Biological Chemistry
• /
• 제20권2호
• /
• pp.182-187
• /
• 1977

본 실험은 대두(大豆)의 발아(發芽)에 따른 trypsin inhibitor activity(TIA)와 protein pattern의 변화에 관하여 조사함과 아울러 그 상관관계를 살퍼보기위한 목적으로 시도되었다. 자엽의 TIA는 발아(發芽)과정중(中) 조금 감소하였고, 배축에서는 급격히 감소해서 발아(發芽) 제 7일에는 제2일의 50%이하로 줄었다. 그리고 발아(發芽) 제 2,3,4일의 defatted dry sample에서 배축은 자엽보다 더 높은 TUI를 보여줬으며 배축의 수분함량이 자엽에 비해 높으므로 fresh sample당(當) TIA는 자엽보다 더 낮았다. 그리고 protein pattern은 자엽과 배축에 있어서 분자량이 큰 15S등의 polymer (band 1), 11S (band 2) 그리고 7S (band 3)가 감소했고 Rm치(値) 자엽의 band 5를 비롯하여 $0.5{\sim}1.0$사이에 높은 mobility를 가진 물질들이 생성(生成)되었다. 자엽의 band 4와 배축의 band 6은 거의 변하지 않았다. 그리고 발아에 따라 TIA의 감소와 저 장단백질의 감소는 있었으나 그 감소량이 서로 일치하지는 않았다.