• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.87-93
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• 2021

As the portion of modern weapons systems equipped with electronic components increases, the presence of embedded software has also increased, subsequently drawing interest in quality management and development methods. Unlike mechanical systems, software is logically intangible, hard to troubleshoot, and hard to reuse, making it hard to utilize limited resources when exposed to failures. The United States had successful results in establishing the Capability Maturity Model (CMM) by studying and applying separate processes for development and quality management of defense software. South Korea has also established, and utilizes, a standard of development and quality management for defense software based on international standards. However, some say those standards still remain at a basic level, and should be modified along with the progress in software. If the standard stays at a basic level, compared to software progression, the cost to reuse and restore resources will increase exponentially. This paper discusses improvement in the test processes for defense software through the Test Maturity Model-integration (TMMi)-derived from the CMM-and presents a blueprint for defense software quality management.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1057-1069
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• 2020

For most upland crops in Korea, underground water is used to ensure an adequate water supply. Thus, surface water storage tanks are needed to supply surface water from reservoirs or streams. This study discusses the design, manufacture and monitoring of a water storage tank capable of reliably supplying water to crops and preventing the inflow of floating debris. The study was conducted in an apple orchard in Yesan-gun, Chungcheongnam-do in Korea. Based on the water requirements of the crops and size of the orchard, a required flow volume of about 0.6 ㎥·h-1 was determined, along with a surface water storage tank capacity of 1.2 ㎥. Following a comparison with other materials, stainless steel (STS) was used to construct the water tank. The tank was designed to provide 14 hours of irrigation, enabling a small-capacity, cost-efficient tank design to be used. A surface water irrigation test was performed using the surface water storage tank. The average surface water irrigation flow rate was 0.00045 ㎥·m-2·h-1. The water quality test showed that the pH, suspended solids (SS), total nitrogen (TN), and total phosphorus (TP) values satisfied the reference values for agricultural water. The test results showed that the surface water storage tank evaluated in this study allows for crop irrigation when there is a lack of groundwater during droughts.

• Journal of the Korean GEO-environmental Society
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• v.23 no.5
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• pp.15-24
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• 2022

In order to improve dredged area, long time and high cost is needed because of bad engineering and physical conditions. And there is no suitable example of pipe mixing method at domestic site. Moreover, applicability and effectiveness of this method is uncertain and shows different results between site and laboratory test. In order to solve these problems, we determined proper grain size distribution and water content range using dredged soil and reformed material (standard sand & material controlling grain size distribution) in the laboratory test. As a result, we confirmed that coefficient of sediment consolidation is increased and there is an improvement about separation sedimentation. Undrained shear strength was derived by water content of reformed dredging soil through regression analysis of test results. We suggest the correlation equation for determining mixing ratio.

• Journal of the Korean Society of Propulsion Engineers
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• v.27 no.1
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• pp.49-57
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• 2023

The autogenous pressurization has been widely adopted for propulsion systems of next-generation reusable rockets due to its low cost and high reliability. The autogenous pressurization has a simple structure, but an understanding of the heat and mass transfer occurring inside the tank is essential. For this reason, a simulation test of the autogenous pressurization was conceived. The experiment equipment was constructed based on overseas pressurization test facilities cases and expert advice. Unlike the actual autogenous pressurization system, the propellant tank was insulated to exclude external influences. The pressurized gas supply line and the propellant pipe were separated. Using the manufactured autogenous pressure experiment equipment, it is possible to evaluate the condensation phenomenon of pressurants in cryogenic propellants, comparison of the efficiency of pressurization using helium and evaporated gas and the pressurization capacity according to the temperature of pressurant.

• Geomechanics and Engineering
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• v.36 no.6
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• pp.589-599
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• 2024

Dispersion occurs when clay soil disperses under specific conditions and is rapidly washed away. While there are numerous methods for rectifying it, they are neither cost nor time-effective. The current study used metakaolin and zeolite to improve heavily dispersive clay soil either separately or in combination at 0%, 2%, 4%, 6%, and 8% of the soil weight. After 7 days of curing, the samples were tested to determine the extent of change in the dispersion potential, as well as the improvement of the geotechnical properties of the soil. The results indicated that the addition of 2% zeolite with 6% to 8% metakaolin decreased the dispersion potential considerably. Double hydrometry test findings revealed that the dispersion potential decreased by almost 70% and entered the non-dispersive group; the crumb test also revealed this. Atterberg limits testing indicated a decrease in the plasticity index which reduced the flexibility of the samples. The greatest decrease in PI (67.5%) was achieved with the addition of 8% zeolite plus 8% metakaolin to the soil. The results of density tests revealed that a decrease in the optimal moisture content increased the maximum dry density of soil. This increase in density was a response to the high reactivity of metakaolin with calcium hydroxide and the formation of calcium hydroxide hydrate gel. This eventually caused an increase in the unconfined compressive strength, the greatest increase in strength of about 1.8-fold was observed with a combination of 2% zeolite and 6% metakaolin compared to the unmodified sample.

• Steel and Composite Structures
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• v.51 no.4
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• pp.351-361
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• 2024

Accurate measurement of K_IC values for gas pipeline steels is important for assessing pipe safety using failure assessment diagrams. As direct measurement of K_IC was impossible for the API X70 pipeline steel, multi-specimen fracture tests were conducted to measure J_IC using three-point bend geometry. The J values were calculated from load-displacement (F-δ) plots, and the associated crack extensions were measured from the fracture surface of test specimens. Valid data points were found for the constructed J-Δa plot resulting in J_IC=356kN/m. More data points were added analytically to the J-Δa plot to increase the number of data points without performing additional experiments for different J-Δa zones where test data was unavailable. Consequently, displacement (δ) and crack-growth (Δa) from multi-specimen tests (with small displacements) were used simultaneously, resulting in the variation of Δa-δ (crack growth law) and δ-Δa obtained for this steel. For new Δa values, corresponding δ values were first calculated from δ-Δa. Then, corresponding J values for the obtained δ values were calculated from the area under the F-δ record of a full-fractured specimen (with large displacement). Given Δa and J values for new data points, the developed J-Δa plot with extra data points yielded a satisfactory estimation of J_IC=345kN/m with only a -3.1% error. This is promising and showed that the developed technique could ease the estimation of J_IC significantly and reduce the time and cost of expensive extra fracture toughness tests.

• Journal of Korean Academy of Nursing
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• v.12 no.1
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• pp.25-38
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• 1982

As technological civilization and medical science has developed, standards of living have imp-roved and human life expectancy has been extended. But the incidence and mortality rate of cancer have been gradually increasing due to the pollution of the environment. Even though cancer is still a great threat to human beings, the etiology and appropriate cure forcancerhavenotyetbeendiscovered. The early detection and treatment of cancer is urgently needed. This study concentrates on the health behavior of woman regarding the papanicolau smear for early detection of cervical cancer. It was done in order to provide a direction for scientific health education materials by investigating predictors of preventive health behavior. The subjects for this study were made up of 54 woman, who comply with preventive health practices(compliant) who attended the Cervical Cancer Center of Y University Hospital in order to have tests for early detection of cervical cancer and 54 woman who did not comply with preventive health practices (noncompliant) selected from 100 housewives of I apartment, Kang Nam Ku, Seoul. The study method used, was a questionnaire for the compliance group and an interview for the noncompliance group. The period for data collection was from October 13th to October 24th. 1981. Analysis of the data was done using percentages, T-test, Pearson Correlation and Stepwise Multiple Regression. The results of study were as follows: 1. The hypotheses tested were based on the health belief model; 1) The first hypothesis,“The compliant may have more knowledge of the cervical cancer than the noncompliant”was rejected(T=-1.86, p>.05) 2) The second hypothesis,“The compliant may have a higher severity of cervical cancer than the noncompliant”was accepted (T=5.41, p<.001) 3) The third hypothesis, “The compliant may have a higher susceptability to cervical cancer than the noncompliant”was accepted(T=3.51, p<.01). 4) The fourth hypothesis,“The compliant may have more beneHt than cost'from the cervical cancer tests than the noncompliant" was accepted(T=7.46, p<.001). 5) The fifth hypothesis,“The compliant may have more health concern than the noncompliant”. was accepted(T=3.39, p<.01). These results show that severity, susceptability, benefit(over cost) and health concern influence the preventive health behavior in this Study. 2. In the correlation among variables, it was found that the knowledge of cervical cancer and the benefit(over cost) of preventive health behavior were negatively correlated(r=-2.75, p<.01), Severity of cervical cancer and benefit (over cost) of preventive health behavior were positively correlated(r=.280, p＜.01), severity and susceptability of cervical cancer were positively correlated(r= .238, p<.01), benefit(over cost) and health concern were positively correlated(r= .299, p<.01). The benefit(over cost) may be raised by increasing the severity and health concern. Therefore the compliance rate of woman may be raised through health education by increasing the benefit(over cost) of the individual. 3. The Stepwise Multiple Regression between health behavior and predictors. 1) The factor“Benefit(over cost)”could account for preventive health behavior in 34.4％ of the sample(F=55.6204 P<.01). 2) When the factor“Severity”is added to this, it accounts for 44.3% of preventive health behavior(F=41.679, p<.01). 3) When the factor“Susceptability”is also included, it accounts for 46.7% of preventive health behavior(F=30.373, p<.01). 4) When the factor “Health concern”is included, it accounts for 48.1% of preventive health behavior(F=23859, p<.05). This means that other factors appear to influence preventive health behavior, since the combination of variables explains only 48.1％ of the Preventive health behavior. Therefore further study to investigate the predictors of preventive health behavior is necessary.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.917-925
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• 2014

An accurate feed formulation is essential for optimizing feed efficiency and minimizing feed cost for swine and poultry production. Because energy and amino acid (AA) account for the major cost of swine and poultry diets, a precise determination of the availability of energy and AA in feedstuffs is essential for accurate diet formulations. Therefore, the methodology for determining the availability of energy and AA should be carefully selected. The total collection and index methods are 2 major procedures for estimating the availability of energy and AA in feedstuffs for swine and poultry diets. The total collection method is based on the laborious production of quantitative records of feed intake and output, whereas the index method can avoid the laborious work, but greatly relies on accurate chemical analysis of index compound. The direct method, in which the test feedstuff in a diet is the sole source of the component of interest, is widely used to determine the digestibility of nutritional components in feedstuffs. In some cases, however, it may be necessary to formulate a basal diet and a test diet in which a portion of the basal diet is replaced by the feed ingredient to be tested because of poor palatability and low level of the interested component in the test ingredients. For the digestibility of AA, due to the confounding effect on AA composition of protein in feces by microorganisms in the hind gut, ileal digestibility rather than fecal digestibility has been preferred as the reliable method for estimating AA digestibility. Depending on the contribution of ileal endogenous AA losses in the ileal digestibility calculation, ileal digestibility estimates can be expressed as apparent, standardized, and true ileal digestibility, and are usually determined using the ileal cannulation method for pigs and the slaughter method for poultry. Among these digestibility estimates, the standardized ileal AA digestibility that corrects apparent ileal digestibility for basal endogenous AA losses, provides appropriate information for the formulation of swine and poultry diets. The total quantity of energy in feedstuffs can be partitioned into different components including gross energy (GE), digestible energy (DE), metabolizable energy (ME), and net energy based on the consideration of sequential energy losses during digestion and metabolism from GE in feeds. For swine, the total collection method is suggested for determining DE and ME in feedstuffs whereas for poultry the classical ME assay and the precision-fed method are applicable. Further investigation for the utilization of ME may be conducted by measuring either heat production or energy retention using indirect calorimetry or comparative slaughter method, respectively. This review provides information on the methodology used to determine accurate estimates of AA and energy availability for formulating swine and poultry diets.

• Journal of the Korea Concrete Institute
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• v.24 no.4
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• pp.453-463
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• 2012

Steel-concrete composite rigid-frame bridge is a type of integral bridge having advantages in bridge maintenance and structural efficiency from eliminating expansion joints and bridge supports, the main problems in bridge maintenance. The typical steel-concrete composite rigid-frame bridge has the girder-abutment connection where a part of its steel girder is embedded in abutment for integrity. However, the detail of typical girder-abutment connection is complex and increases the construction cost, especially when a part of steel girder is embedded. Recently, a new type of bridge was proposed to compensate for the disadvantages of complex details and cost increase. The compensation are expected to improve efficiency of construction by simplifying the construction detail of the girder-abutment connection. In this study, a static load test has been carried out to examine the behavior of the girder-abutment connection using real-scale specimens. The results of the test showed that the girder-abutment connection of proposed girder bridge has sufficient flexural capacity and rebars to control concrete crack should be placed on the top of abutment.

• Journal of Energy Engineering
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• v.22 no.2
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• pp.96-104
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• 2013

Coal gasification is considered as one of the best alternatives among clean coal technology and new concept next generation technologies are under being developed to achieve low cost as well as high efficiency. In this study we have developed double swirl multi-burner as part of the development of low cost compact gasifier. We installed new concept multi-burner with pulverized coal distributor to the body of existing gasifier for burner test. Gasification test was performed under the condition of $6.4{\sim}7.2kg/cm^2$ and $1170{\sim}1300^{\circ}C$ by using Indonesian ABK (sub-bituminous) coal to get operation condition of new concept multi-burner. Our interest was focused to ensure a stable operating condition rather than the gasifier performance evaluation. As a result, we were able to achieve the carbon conversion of 84% and the cold gas efficiency of 52.1% at the stable operating conditions.