• Transactions on Control, Automation and Systems Engineering
• /
• v.3 no.2
• /
• pp.83-88
• /
• 2001

The robust linear H(sub)$\infty$ FIR filter, which guarantees a prescribed H(sub)$\infty$ performance, is designed for continuous time-varying systems with unknown cone-bounded nonlinearity. The infinite horizon filtering for time-varying systems is systems is investigated in therms of two Riccati equations by the finite moving horizon.

• Restorative Dentistry and Endodontics
• /
• v.16 no.1
• /
• pp.209-215
• /
• 1991

The propose of this study was to evaluate the effect of the variuos antiseptic solutions and distilled water on physical properties of endodontic gutta-percha cone. The antiseptic solutions were 70% isoprophyl alcohol, 5% NaOCl and 2.5% NaOCl, as control gutta-percha cones, did not stored antiseptic solution was used. Observation periods were 1, 5, 10, 20, and 30 days. In each group,. the 15 gutta-percha cones used. A tensile strength and elongation rate measurements were performed with Instron (Instron 4501), cross - head speed was set 10 inch / min. The data were statistically analyzed and the results were as followed. 1. The tensile strength of the gutta-percha cones, stored in distilled water, were slightly decreased (p<0.05). Elongation rate was not significantly different 2. The tensile strength of the gutta-percha cones, stored in 70% isopropyl alcohol, were increased (p<0.01) except 1 day group. 3. The tensile strength of the gutta-percha cone, stored in 2.5% NaOCl, were decreased (p<.0.05). Elongation rate significantly decreased (p<0.01). 4. The tensile strength of the gutta-percha cone, stored in 5% NaOCl, were decreased (p<0.05). Elongation rate significantly decreased (p<0.01). These results showed that the changes of physical properties (tensile strength and elongation rate) in gutta-percha cone were developed after a day' when gutta-percha cone were stored at 70% isopropyl alcohol, 2.5% or 5% NaOCl. So, It was concluded that gutta-percha cone must have been used at least within one day, when they were stored at the above antiseptics. I thought that the study of substantial effects on endodontic treatment due to changes of physical properties in gutta-percha cone will be needed.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.13 no.1
• /
• pp.817-832
• /
• 2021

In this paper, a simple practical method to estimate the drag of Super-Cavitating Underwater Vehicles (SCUV) is proposed that can obtain the drag with only principal dimensions in an initial design stage. SCUV is divided into cavitator, forebody, afterbody, base, and control fin and the drag of each part is estimated. The formulas for the drag coefficient are proposed for the disk and cone type cavitators and wedges used as control fins. The formulas are a function of cavitation number, cone or wedge angle, and Reynolds number. This method can confirm the drag characteristics of SCUV that the drag hump appears according to the coverage of the body by the cavity and the cavitator drag remains only when the entire body is covered by cavity. Applying this method to SCUV of various shapes, it is confirmed that the effects of cavitating and non-cavitating conditions, cavitator and body shape, and speed could be found.

• The korean journal of orthodontics
• /
• v.41 no.6
• /
• pp.431-439
• /
• 2011

Objective: To determine whether there is any difference between the cleft and non-cleft sides of the mandible in unilateral cleft lip and palate (UCLP) patients, or the right and left sides in control patients; and to determine if there is any difference between the mandibular asymmetry of UCLP patients and that of control patients. Methods: We examined cone-beam computed tomography (CBCT) scans of 15 patients with UCLP and 15 age- and gender-matched control patients. We evaluated 8 linear, 3 surface, and 3 volumetric measurements and compared the cleft/non-cleft sides of UCLP patients and the right/left sides of controls. Results: There were no statistically significant gender differences in any linear, surface, or volumetric measurement. The single significant side-to-side difference in UCLP patients was a longer coronoid unit on the cleft side than on the non-cleft side ($p$ = 0.046). Body volume was significantly lower in the UCLP group than in the control group ($p$ = 0.008). Conclusions: In general, UCLP patients have symmetrical mandibles, although the coronoid unit length is significantly longer on the cleft side than on the non-cleft side. UCLP patients and controls differed only in body volume.

• Journal of the Korean Society of Safety
• /
• v.18 no.3
• /
• pp.8-13
• /
• 2003

Equivalent Reynolds equation of truncated cone type SFD bearing using nonnewtonian EV fluid is derived. The 3 nondimensional oil film pressures and its forces are obtained with axial and circumferential pressure gradient of bearing respectively, and dynamic characteristics for the stability of rotor-bearing system are obtaind through the governing equation for an elastic rotational shaft. It is shown that EV fluid is less sensitive to the changes of oil-film than newtonian fluids for dynamic characteristics. Therefore, results show that it is better to use an EV fluid with truncated cone type SFD bearing for the vibration control of rotational machines.

• Journal of Korean Society of Forest Science
• /
• v.83 no.4
• /
• pp.498-504
• /
• 1994

The damage by the black-tipped sawfly, Acantholyda posticalis posticalis Matsumura, has been incheasing at several locations in central part of the Korean peninsula. This study was undertaken at selected plots in locality of Kapyung-gun. Kyunggi Province from 1984 through 1987. The purpose of this study was to provide basic information for integrated control of this pest and to determine the economic threshold by investigating the pest-host interactions with special reference to damage analysis. The results obtained were as follows ; 1. One year old cone formation began to be reduced when 30-40% of the needles were destroyed. With 70% of defoliation, few cones were produced. 2. Number of two year old cone formation and amount of cones began to be reduced when 61-70% of the needles were destroyed ; economic threshold of the defoliation rate retarding the seed production was 51%. 3. Growth of the trees was significantly reduced when more than 50% of the needles were destroyed, and cone production began to be retarded at 30-40% of defoliation. Therefore, it was determined that the economic thresholds requiring the control practices to keep normal tree growth and cone production from being reduced were 50% and 30%, respectively.

• Journal of the Korean Geosynthetics Society
• /
• v.21 no.4
• /
• pp.1-12
• /
• 2022

Generally, the plate load test and the field density test are conducted for compaction quality control in earthwork, and then additional analysis. Recently developed that the DCPT (Dynamic Cone Penetration Test) equipment for smart compaction quality control its the system are able to get location and real-time information about worker history management. The IoT-based the DCPT system improved the time-cost in the field compared traditional test, and the functions recording and storage of the DPI (Dynamic Cone Penetration Index) were automated. This paper describes using these DCPT equipment on in-situ and compared to the standards of the DCPT, and the compaction trend had be confirmed with DPI as the field test data. As a result, the DPI of the final compaction decreased by 1.4 times compared to the initial compaction, confirming the increase in the compaction strength of the subgrade compaction layer 10 to 14 cm deep from the surface. A trend of increasing compaction strength was observed. This showed a tendency to increase the compaction strength of the target DPI proposed by MnDOT and the results of the existing plate load test, but there was a difference in the increase rate. Therefore, additional studies are needed on domestic compaction materials and laboratory conditions for target DPI and correlation studies with the plate load tests. If this is reflected, it is suggested that DCPT will be widely used as smart construction equipment in earthworks.

• Journal of Drive and Control
• /
• v.17 no.2
• /
• pp.9-18
• /
• 2020

The purpose of this study was to analyze the effect of the soil cone index (CI) on the tractor work load. A load measurement system was constructed for measuring the field data. The field sites were divided into grids (3×3 m), and the cone index was measured at the center of each grid. The work load measured through the plow tillage was matched with the soil cone index. The matched data were grouped at 600 kPa intervals based on the cone index. The work load according to the cone index was analyzed for engine, axle, and traction load, respectively. The results showed that when the cone index increased, engine torque decreased by up to 9%, and the engine rotational speed and brake-specific fuel consumption increased by up to 5% and 3%, respectively. As the cone index increased, the traction and tillage depth were inversely proportional to the cone index, decreasing 7% and 18%, respectively and the traction and tillage depth were directly proportional to the cone index, increasing 13% and 12%, respectively. Thus, it was found that the cone index had a major influence on the engine, axle, and traction loads of the tractor.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.9
• /
• pp.1342-1348
• /
• 2014

Seeds of Korean pine cone (Pinus koraiensis) have long been consumed as an edible food in countries located in North-East Asia, On the other hand, Korean pine cone, containing various polyphenols, is discarded as a useless garbage after removing seeds. This study investigated the lipolytic effects of pine cone extract in differentiated 3T3-L1 adipocytes. Intracellular lipid accumulation was measured by Oil red O staining, free glycerol release by colorimetric reaction, and expression of genes related to lipid metabolism by real-time PCR. Compared to control, pine cone extract reduced intracellular lipid accumulation by 8.8% and increased free glycerol release by 8.2% a concentration of $5{\mu}g/mL$ in differentiated 3T3-L1 adipocytes. mRNA levels of fatty acid synthesis were not significantly different between control and pine cone extract, but mRNA levels of lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) significantly increased by 38.7% and 94.1% at a concentration of $5{\mu}g/mL$, respectively. Thus, pine cone extract is suggested to have lipolytic effects through induction of LPL and HSL gene expression.

• Journal of Biosystems Engineering
• /
• v.41 no.4
• /
• pp.304-312
• /
• 2016

Purpose: Soil strength has been measured using a cone penetrometer, which is making it difficult to obtain the spatial data required for precision agriculture. Our objectives were to evaluate real-time horizontal soil strength (RHSS) to measure soil strength in real time while moving across the field. Using the RHSS data, the tillage depth was determined, and the power consumption of a tractor and rotavators were compared. Methods: The horizontal soil-strength index (HSSI) obtained by the RHSS was compared with the cone index (CI), which was measured using a cone penetrometer. Comparison analysis in accordance with the measurement depth that increased at 5-cm interval was conducted using kriged maps at six sensing depths. For tillage control and evaluation of the power consumption, the system was installed with a potentiometer for tillage depth, a torque sensor from the rear axle, and a power take-off (PTO) shaft. Results: The HSSI was lower than the CI, but they were the same at 54.81% of the total grids for the 5-cm depth and at 3.85% for the 10-cm depth. In accordance with the recommended tillage map, tillage operations between 0 and 15 cm left 2.3% and 7% residue cover on the soil, and that between 20 and 10 cm covered a wider utilization of 3% and 18.4%, respectively. When the tillage depth was 15 cm, the comparison result of the power requirements between the PTO and rear axle in terms of control performance revealed that the maximum power requirements of the axle and PTO were 44.63 and 23.24 kW, respectively. Conclusions: An HSSI measurement system was evaluated by comparison with the conventional soil strength measurement system (CI) and applied to a tractor to compare the tillage power consumption. Further study is needed on its application to various farm works using a tractor for precision agriculture.