• Journal of Sensor Science and Technology
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• v.8 no.3
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• pp.253-258
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• 1999

This paper is written for the purpose of obtaining the information about the weather easily by the development of weather forecast system sensing temperature, humidity, and atmospheric pressure as key information. For this, data is obtained from the Weather Bureau, and analyzed in order to set a standard of weather forecast from the collected data. The pressure sensor and temperature-humidity sensor are fabricated using the piezoresistive effect of semiconductor, which are used to collect data. The weather forecast system is made using microprocessor.

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.409-414
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• 2001

This paper reports a technique for measuring a three-dimensional soil deformation and a simplified method to determine the three-dimensional contact area of agricultural tires in a soil bin. A Pirelli 12.4R28 radial-ply tire was used on soft soil. Effects of dynamic load and inflation pressure were determined using the equipment for measuring soil deformation on the soil surface. Soil deformation measurements were made under three conditions of over-load (59kPa-14.2kN), rated-load (108kPa-11.8kN) and under-load (157kPa-9.3kN) in the combinations of the inflation pressures (kPa) and the tire load (kN). The results from three conditions were shown that the contact area of the over-load increased considerably bigger than those of the rated-load and the under-load. Therefore, to regulate soil deformation, the inflation pressure and the tire load should be set according to the soil conditions.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.1
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• pp.172-178
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• 1990

To predict the qualitative performance characteristics of Stirling Engines, an analytical approach to the Ideal Adiabatic Model set up by Urieli et al. has been treated. First, volume variations of both the expansion and the compression cylinders are approximated to piecewise linear function of the crank angle, which make it possible to specify the mass flow direction of each cylinder a priori to solve a set of basic equation. In consequences, an engine cycle can be considered as a combination of 4-type fundamental process. For each process, pressure is obtained as a solution of the algebraic equation. Application of the cyclic steady condition to the whole cycle completes the analysis. Further investigations result in analytical expressions for cyclic heat and work in terms of dependent variables determined from the pressure. The results are expected useful in establishing the preliminary design conditions of Stirling Engines.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.237-242
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• 1999

As one of the key parameters to determine $CO_2$ flux between air - sea interface, it is quite important to know p$CO_2$, which has involved much uncertainty, mainly due to the complex variations of sea surface p$CO_2$ and the paucity of samples, made in ocean. In order to improve the interrelationship between partial pressure (p$CO_2$) and different physical and biochemical parameters in global sea surface water, a new empirical relation is established to correlate and parameterize p$CO_2$ in the mixed layer using the data from recent WOCE cruises. Meanwhile, by new empirical relation, abundant historical hydrographic and nutrients ship data, Levitus data set and NOAA/AVHRR(SST), p$CO_2$ have been accumulated and applied. Then effort has to be made fur promotion of this study to correlate and parameterize p$CO_2$ in the mixed Layer with different physical and biochemical parameters. and further attribute this huge historical data sets and NOAA/AVHRR(SST) data to estimate p$CO_2$. In this paper we analyzed more interrelationship between the model and ship/satellite data set. Finally, the inter-annual variations of p$CO_2$ in sea are presented and discussed.

• Nuclear Engineering and Technology
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• v.45 no.6
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• pp.767-790
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• 2013

MAAP4 is a computer code that can simulate the response of a light water reactor power plant during severe accident sequences, including actions taken as part of accident management. The code quantitatively predicts the evolution of a severe accident starting from full power conditions given a set of system faults and initiating events through events such as core melt, reactor vessel failure, and containment failure. Furthermore, models are included in the code to represent the actions that could mitigate the accident by in-vessel cooling, external cooling of the reactor pressure vessel, or cooling the debris in containment. A key element tied to using a code like MAAP4 is an uncertainty analysis. The purpose of this paper is to present a MAAP4 based analysis to examine the sensitivity of a key parameter, in this case hydrogen production, to a set of model parameters that are related to a Level 2 PRA analysis. The Level 2 analysis examines those sequences that result in core melting and subsequent reactor pressure vessel failure and its impact on the containment. This paper identifies individual contributors and MAAP4 model parameters that statistically influence hydrogen production. Hydrogen generation was chosen because of its direct relationship to oxidation. With greater oxidation, more heat is added to the core region and relocation (core slump) should occur faster. This, in theory, would lead to shorter failure times and subsequent "hotter" debris pool on the containment floor.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.622-627
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• 2001

The object of this paper is to compare stress intensity factor that be calculated by Raju-Newman's equation, finite element method, and Vessel INTegrity analysis inner flaws(VINTIN) program for longitudinal semi-elliptical cracks in cylindrical vessel under inner pressure. For this, three-dimensional finite-element analyses were performed to obtain the stress intensity factors for various surface cracks with t/R = 0.1. The finite element meshes were designed for various crack shapes with t/R of 0.1. The crack depth to thickness ratio, a/t, was set to 0.2 and 0.5 matching Raju-Newman's equation. The crack depth to length ratio, a/c, was set to 0.2 and 0.4 in the same way and 0.33 was added to extend the range of crack configuration. Finite Element Analyses(FEA) were performed using the commercial FEA program ABAQUS. The results showed that the Raiu-Newman solutions were about 4-10% lower than FEA's using symmetric model of one-eighth of a vessel and close to those of FEA using symmetric model or one-forth or a vessel. Ana VINTIN solutions were nearly equal to those or Raju-Newman.

• The KSFM Journal of Fluid Machinery
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• v.15 no.6
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• pp.39-45
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• 2012

This paper describes the outcome of the design of a 200 kW class micro gas turbine and the sensitivity of its performance (efficiency and power) to the variations in major design parameters. The reference design parameters were set up based on the best available component technologies. The resulting net electricity generation efficiency of the micro gas turbine package was found to be competitive to those of other systems in the market. The sensitivities of power and efficiency to the variations in compressor and turbine efficiencies, pressure ratio, turbine inlet temperature, recuperator effectiveness, secondary air ratio, pressure loss ratios of both the cold and hot sides of the recuperator were estimated. Based on the sensitivity data, a simplified method to predict the variation in system performance responding to the combinations of small changes in all design parameters were set up and validated.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.301-307
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• 2012

We investigated the effects of non-meat protein binders combined with glucono-${\delta}$-lactone (GdL) on the binding properties regarding restructured pork prepared by high-pressure treatment. Soy protein isolate (SPI), casein (CS), whey protein concentrate (WPC), and egg white (EW) were used as non-meat protein binders and compared with the control (no binder) and with the ${\kappa}$-carrageenan (KC) treatment. The compression and depression rates were 2.3 and 37 MPa/s, respectively, and pressurization was conducted at 200 MPa for 30 min at $4^{\circ}C$. After pressurization, the physical properties (pH, water-holding capacity, color, tensile strength, and microscopic structure) of the sample were evaluated. The combination of pressurization with acidification enabled cold-set meat binding, and the binding strength of restructured pork was enhanced by the addition of non-meat proteins. Among binders, SPI demonstrated the best efficiency in binding meat pieces. Therefore, the present study demonstrated that the combination of acidification and pressurization processes with the utilization of non-meat protein binders has a potential benefit in meat restructuring.

• Korean Journal of Materials Research
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• v.12 no.7
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• pp.580-586
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• 2002

The effect of processing and designing variables such as pouring temperature(1400 or $1500^{\circ}C$), inoculation and risering design(T and H type) on the formation of defects such as external depression, primary and secondary shrinkage cavities in GC150 gray cast iron was investigated. In T type risering design, external depression or primary shrinkage cavity due to liquid contraction was formed in all of the eight cases. Regardless of its modulus value, the riser could not function properly in T type risering design because directional solidification was not promoted toward the riser. On the other hand, the four cases of H type risering design in which thermal sleeves were set onto the risers produced defect-free castings. In both types of the risering designs, secondary shrinkage cavity caused by solidification contraction was not observed in the casting because of the expansion pressure due to graphite precipitation and the application of rigid pep-set mold. The degree of external depression or primary shrinkage cavity was reduced with lowered pouring temperature. The effect of inoculation was diminished because of the high carbon equivalent of GC 150 gray cast iron.

• Korean Journal of Materials Research
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• v.16 no.11
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• pp.698-704
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• 2006

In this study, the effect of chill layers occurred in shot sleeve on the molten metal filling was analyzed through computer simulation. The behavior of chill layers with temperature variation of shot sleeve set from 200 to $280^{\circ}C$ was also investigated. The simulation results showed the chill layers set in the in-gates during the injection process change the main filling direction and cause turbulent flow pattern, resulting in porosities inside the castings. The amount of chill layers with the increasing temperature of shot sleeve was considerably reduced. Particularly, at the setting temperature of $280^{\circ}C$ by heat control unit, the biggest reduction in chill layers, excellent trimmed surface and the highest density were achieved, suggesting that as the optimal sleeve condition in aluminum high pressure diecasting, especially for highly complex parts like valve body.