• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.10
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• pp.739-745
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• 2022

In various environmental requirements of a fighter aircraft, the explosive atmosphere is a test to verify whether or not military products are ignited for the safety of the aircraft system and crew. For the test, the explosive atmosphere test chamber owned by the Korea Institute of Industrial Technology (KITECH) was applied, and n-hexane, which has more sensitive ignition characteristics than general fuel, was used to conduct the test conservatively. Based on Procedure I, Method 511.6, MIL-STD-810G w/Change 1, the US military environmental test specification, the scope of application, tailoring guide, and detailed test procedures are checked, and the necessity of this test for each subsystem of the fighter aircraft is considered. In this study, we present the correct tailoring method by analyzing the explosive atmosphere test results for the components installed in the fighter aircraft and sharing the derived essential points.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.87-94
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• 2019

In this paper, we test procedures to demonstrate operating environmental conditions that can be exposed to UAV during its life-cycle are proposed. They are set up to be used in a large-sized climate chamber, one of the facilities of the Agency for Defense Development corresponding with the system requirements. The test steps and profile details were more specifically suggested for rainfall, humidity, and temperature (low-temperature storage and operation, high-temperature operation and solar radiation), and MIL-STD-810G w/Change-1-based.

• Journal of Nutrition and Health
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• v.26 no.4
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• pp.405-413
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• 1993

The longitudinal changes on human milk volume of 27 Korean lactating women (primiparae=10, multiparac=17) from 0.5 to 6 months after parturition have been studied by test-weighing method in Cheongju and Anseong area. The human milk volume per day increased to 2 months postpartum, and then decreased during lactation. The mean volume(g/day) at 0.5, 1, 2, 3, 4, 5, and 6 months were 634, 810, 847, 840, 844, 810, and 732g, respectively. The average volume were 791 ($\pm$149) and 786($\pm$131)g for primiparae and multiparae, respectively. The overall mean volume was 788$\pm$135g/day. The distributions of the individual mean volume during the first 6 months of lactation were found 450~549g(3.7%), 550~649g(11.1%), 650~749g(22.2%), 750~849%(37.1%), 850~949g(18.6%), 950~1049g(3.7%), and 1050~1149g(3.7%). The mean volume between primiparae and multiparase was significantly lower than other periods. The peak milk volume during the lactation was observed at 3 months postpartum for primiparae(40%), 2 months postpartum for multiparae(35.3%), and 2 months postpartum for total lactating women(29.6%). The volume of human milk had a significant positive correlation with peak volume and infant milk intake, but no correlation with maternal age, weight before delivery, height, and birth weight.

• Journal of Applied Reliability
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• v.14 no.2
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• pp.114-121
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• 2014

An environmental test has been performed in order to improve the lifetime and reliability of the electrical units on aircraft. However, faults occurring in the field of aircraft have been difficult to predict and prevent, and new concepts for reliability testing are desired. Therefore, a composite reliability test sequence was proposed in the conventional studies. This study introduces test sequence guidelines based on relevant principles and considerations for electronic testing according to International Standard IEC-60068-1 and the United States Military Standard MIL-STD-810G. In addition, we analyze possible causes of failure using two-step QFD based on aircraft operation scenarios. Finally, the proposed test sequence can reproduce various and realistic failure modes for electrical units on aircraft.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.262-266
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• 2014

Military vehicle equipped with an antenna and a shelter for operating radar has a vibration exposure during driving time. This vibration would have influence on structure of military vehicle critically. In this paper, driving stability of the military vehicle is obtained through the vibration response analysis. And, vibration level of the military vehicle satisfied the military vibration specification through analysis and comparing the MIL-STD-810G. PSD and Grms data obtained by road test can be used for vibration test specification of cabinets and electronic equipment in shelter.

• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.261-266
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• 2020

When a KW-class power control unit is installed in an aircraft installation, a heat dissipation design for a large amount of heat generated during power conversion should be considered. Failure to provide adequate heat dissipation can lead to equipment malfunction and fire, which can be a fatal factor in aviation operations. This paper describes the heat dissipation design of a KW-class power control unit installed in aircraft installation. The design and manufacturing test were conducted through computerized analysis, and the analysis model was corrected by confirming the rapid heat generation phenomenon of the heating element due to high power control. After the model revision, the design was improved, and the high-temperature operation test of the US military standard MIL-STD-810G was performed to confirm the feasibility of the improved design.

• Communications of the Korean Mathematical Society
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• v.13 no.4
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• pp.801-810
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• 1998

Let A(z), W(z) and C(z) be power series with operator coefficients such that W(z) = A(z)C(z). Let D(A) and D(C) be the state spaces of unitary linear systems whose transfer functions are A(z) and C(z) respectively. Then there exists a Krein space D which is the state space of unitary linear system with transfer function W(z). And the element of D is of the form (f(z) ＋ A(z)h(z), k(z) ＋ C＊(z)g(z)) where (f(z),g(z)) is in D(A) and (h(z),k(z)) is in D(C).

• Journal of the Korean Society of Food Culture
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• v.25 no.6
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• pp.810-819
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• 2010

The objective of this study was to produce muffins with added dukeum ramie leaf powder and to compare them to a control. We used two different optimal composition ratios to produce muffins. The physical and sensory characters were varied by changing the ratio of dukeum ramie leaf powder, butter, and sugar to identify a critical value using response surface regression analysis. The ranges for the added dukeum ramie leaf powder, sugar, and butter were 15-35, 60-100, and 60-100 g, respectively. Muffins with added dukeum ramie leaves had comparable mineral and antioxidant vitamin compositions to those of dried ramie leaves. Muffins with added dukeum ramie leaf powder satisfied the suitability of the model, showing a p-value within 5% of significance level (p<0.05) for every aspect Volume and height differed without any association to ingredients. Lightness increased when less dukeum ramie leaf powder was added with more butter and sugar, redness increased when more dukeum ramie leaf powder and sugar were added with 70-80 g of butter, whereas yellowness increased when less dukeum ramie powder was added. Texture and toughness increased when less dukeum ramie leaf powder was added. The degree of gumminess and chewiness depended hugely on the amount of sugar. Cohesiveness, decreased with more dukeum ramie leaf powder and butter, whereas hardness increased with a medium range of ingredients. Sensory character increased with less dukeum ramie powder, and overall quality increased with more butter and sugar, but depended on the amount of added dukeum ramie power. The critical values from the sensory characteristics showed that 27 g of dukeum ramie powder, 72 g of sugar, and 86 g of butter was optimum.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.810-814
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• 2013

The thermodynamic parameters for the intercalative interaction of structurally related well known intercalators, 9-aminoacridine (9AA) and proflavine (PF) were determined by means of fluorescence quenching study. The fluorescence intensity of 9AA decreased upon intercalation to DNA, poly[$d(A-T)_2$] and poly[$d(G-C)_2$]. A van't Hoff plot was constructed from the temperature-dependence of slope of the ratio of the fluorophore in the absence and presence of a quencher molecule with respect to the quencher concentration, which is known as a Stern-Volmer plot. Consequently, the thermodynamic parameters, enthalpy and entropy change, for complex formation was calculated from the slope and y-intercept of the van't Hoff plot. The detailed thermodynamic profile has been elucidated the exothermic nature of complex formation. The complex formation of 9AA with DNA, poly[$d(A-T)_2$] and poly[$d(G-C)_2$] was energetically favorable with a similar negative Gibb's free energy. On the other hand, the entropy change appeared to be unfavorable for 9AA-poly[$d(G-C)_2$] complex formation, which was in contrast to that observed with native DNA and poly[$d(A-T)_2$] cases. The equilibrium constant for the intercalation of PF to poly[$d(G-C)_2$] was larger than that to DNA, and was the largest among sets tested despite the most unfavorable entropy change, which was compensated for by the largest favorable enthalpy. The favorable hydrogen bond contribution to the formation of the complexes was revealed from the analyzed thermodynamic data.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1761-1768
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• 2006

In this study, the comparative effects of transgenic corn (Mon 810 and Event 176) and isogenic corn (DK729) were investigated for their influence on in vitro rumen fermentation. This study consisted of three treatments with 0.25 g rice straw, 0.25 g of corn (Mon810/Event176/DK 729) mixed with 30 ml rumen fluid-basal medium in a serum bottle. They were prepared in oxygen free conditions and incubated at $39^{\circ}C$ in a shaking incubator. The influence of transgenic corn on the number of bacterial population, F. succinogenes (cellulolytic) and S. bovis (amylolytic), was quantified using RT-PCR. Fermentative parameters were measured at 0, 2, 4, 8, 12 and 24 h and substrate digestibility was measured at 12 and 24 h. No significant differences were observed in digestibility of dry matter, NDF, ADF at 12 and 24 h for both transgenic and isogenic form of corns (p>0.05) as well as in fermentative parameters. Fluid pH remained unaffected by hybrid trait and decreased with VFA accumulation as incubation time progressed. No influence of corn trait itself was seen on concentration of total VFA, acetic, propionic, butyric and valeric acids. There were no significant differences (p<0.05) in total gas production, composition of gas (methane and hydrogen) at all times of sampling, as well as in NH3-N production. Bacterial quantification using RT-PCR showed that the population number was not affected by transgenic corn. From this study it is concluded that transgenic corn (Mon810 and Event 176) had no adverse effects on rumen fermentation and digestibility compared to isogenic corn. However, regular monitoring of these transgenic feeds is needed by present day researchers to enable consumers with the option to select their preferred food source for animal or human consumption.