This study evaluates the performance of three theoretical models for correcting dynamic pressure affected by tube length. The experiments involved measuring sinusoidal pressure waves with varying frequency bandwidths, using tubing systems ranging from 20 cm to 300 cm in length including multiple tubing systems connecting three or more tubes. The results showed that the Bergh and Tijdeman models, with constant and variable polytropic parameters respectively, had superior correction performance for various tube lengths, while the Whitmore & Leondes model showed discrepancies. The Bergh & Tijdeman model, with a polytropic parameter of 1.4, is recommended due to its convenience and accuracy. Furthermore, including the inner volume of the pressure transducer in the theoretical model was found to be crucial for accurate correction, as not doing so caused significant errors. The Bergh & Tijdeman model was also found to efficiently correct tube length effects in multiple tubing systems, eliminating the need for time-consuming and laborious experiments.

Buckling Restrained Braces can not only express the strength considered at the time of design, but also reduce the seismic load by energy dissipation according to the plastic behavior after yield deformation of the steel core. The physical characteristics and damping effect may be different according to the buckling prevention method of the steel core by the lateral restraint element. Accordingly, in this study, To compare hysteresis characteristics, Specimen(BRB-C) filled with mortar, specimen(BRB-R) combined with a buckling restraint ring and Specimen(BRB-EP) filled with engineering plastics was fabricated, and a cyclic loading test was performed. As a result of the cyclic loading test, the maximum compressive strength, cumulative energy dissipation and ductility of each test specimen was similar. But in case of the cumulative energy dissipation and ductility, BRB-C filled with the mortar specimen showed the lowest. This is considered to be because the gap between the steel core and the reinforcing material for plastic deformation was not uniformly formed by pouring mortar around the core part.

This study proposes an RCS composite damping device that can achieve seismic reinforcement of existing buildings by dissipating energy by inelastic deformation. A series of experiments assessing the performances of the rubber core pad, hysteretic steel slit damping device, and hybrid RCS damping device were conducted. The results showed that the ratios of the deviations to the mean values satisfied the domestic damping-device conformity condition for the load at maximum device displacement in each direction, at the maximum force and minimum force at zero displacement, as well as the hysteresis curve area. In addition, three analysis models based on load-displacement characteristics were proposed for application to seismic reinforcement design. In addition, the validity of the three proposed models was confirmed, as they simulated the experimental results well. Meanwhile, as the shear deformation of the rubber-core pad increased, the hysteretic behavior of super-elasticity greatly increased the horizontal force of the damping device. Therefore, limiting the allowable displacement during design is deemed to be necessary.

본 연구의 주제는 평화체제와 평화협정이다. 본 연구는 한반도 평화체 제는 국제정치 보편의 맥락과 닿아있는데, 최근 논의들이 시간적으로는 현안, 공간적으로는 한반도에 국한하여 이루어지고 있다는 문제의식에 기초하였다. 이와 관련, 한반도 평화협정과 특성을 공유하는 - 관계정상 화와 협정 주 객체의 지위 변화 – 일소 공동선언(1956), 일중 공동성명 (1972), 바르샤바(1970) 및 프라하 조약(1973), 2+4 조약(1990)과 오스트 리아 국가조약(1955)을 분석, 이를 관통하는 공통 요소를 추출하는데 연 구 주안점을 두었다. 관계정상화의 성격을 띤 조약들의 경우 외교관계 회복 및 상호관계의 포괄적 발전 방안에 대한 내용을 포함하였다. 또한 분쟁당사자간 관계 재설정 차원에서, 청구권, 포로송환, 국제법 원칙 확 인 및 국경의 안정성과 관련된 내용이 비중있게 반영되었다. 조약 주 객 체의 지위 변경 관련 조약들에서는 조약 서명 당사국의 보증 아래, 영토 와 군사력 등 지위 변경된 객체 규정 관련 내용이 중요 부분을 구성하였 다. 본 연구는, 평화체제 관련 기초적 데이터를 제공, 향후 한반도 평화 체제 논의 국면에서 한국의 국익을 투영하면서 그 체제의 안정적 작동을 위한 요소 구상에 기여할 수 있다는 의의를 지닌다.

본 연구는 2019년부터 2021년 9월까지 수집된 홀스타인 젖소 19,930두의 자료를 수집하였으며, 3 SD (Standard Deviation, SD) 범위에서 벗어나는 이상치를 제외한, 8,675두를 분석에 이용하였다. 자료분석은 Statistical Analysis System (SAS) 9.4 software를 사용하였고, 뒷유방높이, 뒷유방너비, 유방깊이, 유두길이 및 유두둘레의 실측치를 사용하였다. 그리고 뒷유방높이, 뒷유방너비, 유방깊이, 유두길이 및 유두둘레의 실측치와 산차, 305일 유량, 비유단계 및 착유속도의 환경요인의 효과를 추정하였다. 산차와 유량이 증가함에 따라 뒷유방너비, 유두길이 및 유두둘레의 실측치는 유의적으로 증가하는 것으로 나타났으며(p < 0.0001), 비유단계에 따라서 뒷유방너비 및 유방깊이의 실측치는 비유단계가 증가할수록 유의적으로 감소하는 것으로 나타났다(p < 0.0001). 각 환경효과에 따른 유방형질 실측치의 표현형 상관의 결과에서는 뒷유방너비와 유방깊이 실측치가 산차 및 유량수준에 대해 높은 상관을 나타냈으며, 특히, 유방형질 중 유방깊이 실측치와 산차에 대해 -0.40 ~ -0.67로 높은 음(-)의 상관을 보였다. 본 연구 결과로 미루어 볼 때, 유방형질이 유생산에 밀접한 관련이 있는 만큼 중요한 형질로 취급되어야 하며, 이들의 기초연구와 함께 유전적 특성을 구명하는 등 더 많은 연구가 수행되어야 할 것으로 사료된다.

To enhance the efficacy of Abeliophyllum distichum leaves, extracts were prepared using different solvents for hydrolytic enzyme-treated Abeliophyllum distichum leaves. Physicochemical quality and antioxidant activity were measured. Soluble solids, reducing sugar, ascorbic acid, flavonoids, and polyphenols contents showed the lowest values in the control without enzyme treatment. However, they showed high contents in ethanol extract. In the case of enzyme treatment, their values were higher than those of the control. In particular, verbascoside content increased about 220 times more than that of the control group when treated with enzymes and extracted with 50% ethanol. pH was lowered upon enzymatic treatment. Regarding DPPH radical scavenging activity, for enzyme-free, 25% ethanol extract showed the highest activity among extracts with different solvents. For cellulase and pectinase-treated leaves, water extract showed the highest DPPH radical scavenging activity among extracts with different solvents. For leaves treated with enzyme combination, 50% ethanol extract showed the highest DPPH radical scavenging activity among extracts with different solvents. Regarding ABTS radical scavenging activity, it was generally higher in the 50% ethanol extract than in the water extract and 25% ethanol extract. In particular, verbascoside content was increased when the extract was prepared by co-treatment with enzymes and 50% ethanol.

본 연구에서는 칡의 효율적인 제거 방법을 모색하기 위해 국내외의 사례를 비교하였다. 칡은 척박한 토지에서도 생장이 왕성한 특성을 가져 사면침식을 억제하는 식물로 이용되기도 하였다. 그러나 칡은 덩굴을 형성하여 조림목을 감고 올라가 생장하므로 심할 경우에는 조림목의 고사를 유발한다. 최근에는 생활권 수목에 대한 관심의 증가로 조경수에 대한 피해가 주목을 받고 있다. 칡은 물리적, 화학적 및 생물학적 방법으로 제거한다. 국내에서는 덩굴 및 주두부 제거 등 물리적 제거 방법과 제초제를 사용하는 화학적 방법을 주로 사용하고 국외에서는 화학적 방법에 주로 의존한다. 물리적 방법은 환경오염이 적은 이점이 있으나 상당한 노동력과 비용이 소요된다. 화학적 방법은 즉각적으로 제거 효과가 나타나지만 약제 사용에 의한 환경오염과 기상조건의 제약이 있다. 생물학적 방법은 화학적 방법의 환경오염을 해결하기 위해 개발되었으나 제거 효과가 느리게 나타나고 조림지에 적용 시 조림목과 하층식생에 미치는 영향에 대한 우려가 있다. 향후 고효율성을 담보하며 친환경적인 생력화 칡 제거 기술에 대한 연구와 적용이 필요하다.

There are many different types of cultivation in tomatoes for year-round production. One of them, semi-forcing cultivation is characterized by growing seedlings in winter season. If grafted seedlings are used in winter season that energy cost can be reduced, because they have tolerance to cold stress. This study was conducted to analyze the rootstock performance by measuring the growth, yield, and leaf-macronutrient content of cherry tomatoes grown in semi-forcing hydroponics. Three domestic rootstocks ‘HSF4’, ‘21LM’, ‘21A701’, and a control cultivar ‘B-blocking’ were grafted onto jujube-shaped cherry tomato (Lycopersicon esculentum L.) commercial cultivar ‘Nonari’. The total yield per plant with grafted cherry tomato ‘21A701’ was 3,387g, which was 11%, 22% and 24% higher than the yield with ‘B-blocking’, non-grafted one and ‘HSF4’. The stem diameter of ‘21A701’ was thick with 8.26mm, whereas non-grafted one was thin with 7.23mm at 160 days after transplanting. The flowering position of ‘21LM’ was 34% and 47% higher than the flowering position of ‘B-blocking’ and non-grafted one at 153 days after transplanting. The NO3-N concentration in petiole sap of ‘21LM’ was the highest with 1,746mg·L-1 and non-grafted one and ‘HSF4’ were the lowest with 1,252mg·L-1 and 1,245mg·L-1 at 167 days after transplanting. The results indicated that rootstock/scion combinations in cherry tomatoes can affect the plant growth, yield, and the concentration of different NO3-N in leaves at the late growth stage. Both ‘21A701’ and ‘21LM’ have vigorous root system, which influence the growth and yield increased.

In this study, to improve the performance of kitchen range hoods, a comparative analysis of air volume and noise is conducted using three ducts by changing shapes. It was found that the difference in air volume was caused by the pressure difference received by each shape. The noise data can be found to be no more than 60dB overall, except for the second tier of A-type. The difference when connecting the circular, square, and flexible ducts was judged to be due to some laboratory noise, and it was found that there was no difference.