• 한국물환경학회지
• /
• 제25권1호
• /
• pp.7-17
• /
• 2009

Soil and Water Assessment Tool (SWAT) was used to assess the impact of potential future climate change on the water cycle and soil loss of the Daecheong reservoir watershed. A sensitivity analysis using influence coefficient method was conducted for two selected hydrological input parameters and three selected sediment input parameters to identify the most to the least sensitive parameters. A further detailed sensitivity analysis was performed for the parameters: Manning coefficient for channel (Cn), evaporation (ESCO), and sediment concentration in lateral (LAT_SED), support practice factor (USLA_P). Calibration and verification of SWAT were performed on monthly basis for 1993~2006 and 1977~1991, respectively. The model efficiency index (EI) and coefficient of determination ($R^2$) computed for the monthly comparisons of runoffs were 0.78 and 0.76 for the calibration period, and 0.58 and 0.65 for the verification period. The results showed that the hydrological cycle in the watershed is very sensitive to climate factors. A doubling of atmospheric $CO_2$ concentrations was predicted to result in an average annual flow increase of 27.9% and annual sediment yield increase of 23.3%. Essentially linear impacts were predicted between two precipitation change scenarios of -20, and 20%, which resulted in average annual flow and sediment yield changes at Okcheon of -53.8%, 63.0% and -55.3%, 65.8%, respectively. An average annual flow increase of 46.3% and annual sediment yield increase of 36.4% was estimated for a constant humidity increase 5%. An average annual flow decrease of 9.6% and annual sediment yield increase of 216.4% was estimated for a constant temperature increase $4^{\circ}C$.

• 한국산업보건학회지
• /
• 제15권1호
• /
• pp.45-51
• /
• 2005

This survey was performed to measure concentrations of airborne microbes, utilizing the six-stage cascade air sampler, according to the sampling site and time in the general hospital and to evaluate the degree of correlations between airborne microbes and environmental factors. Besides the main lobby, airborne microbes and environmental factors were not significantly different between the forenoon(9:00-10:00 AM) and afternoon(2:00-3:00 PM). Concentrations of airborne bacteria and fungi were 404 and $156CFU/m^3$ in the main lobby, 188 and $56CFU/m^3$ in the intensive care unit, 323 and $96CFU/m^3$ in the ward, 239 and $127CFU/m^3$ in the laboratory, and 139 and $33CFU/m^3$ in the newborn baby room, respectively. As a result, the level of airborne microbes was significantly highest in the main lobby and lowest in the newborn baby room(p<0.05). Outdoor airborne microbes concentrations were significantly lower than those of the sampling sites in the general hospital except for the newborn baby room(p>0.05). It was observed that temperature, relative humidity and carbon dioxide in the general hospital had generally positive correlation with airborne microbes. However, there was no correlation between the odor index level and airborne microbes.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권1호
• /
• pp.47-53
• /
• 2018

Objective: The objective of this experiment was to investigate the effects of heat stress on milk protein and blood amino acid profile in dairy cows. Methods: Twelve dairy cows with the similar parity, days in milk and milk yield were randomly divided into two groups with six cows raised in summer and others in autumn, respectively. Constant managerial conditions and diets were maintained during the experiment. Measurements and samples for heat stress and no heat stress were obtained according to the physical alterations of the temperature-humidity index. Results: Results showed that heat stress significantly reduced the milk protein content (p<0.05). Heat stress tended to decrease milk yield (p = 0.09). Furthermore, heat stress decreased dry matter intake, the concentration of blood glucose and insulin, and glutathione peroxidase activity, while increased levels of non-esterified fatty acid and malondialdehyde (p<0.05). Additionally, the concentrations of blood Thr involved in immune response were increased under heat stress (p<0.05). The concentration of blood Ala, Glu, Asp, and Gly, associated with gluconeogenesis, were also increased under heat stress (p<0.05). However, the concentration of blood Lys that promotes milk protein synthesis was decreased under heat stress (p<0.05). Conclusion: In conclusion, this study revealed that more amino acids were required for maintenance but not for milk protein synthesis under heat stress, and the decreased availability of amino acids for milk protein synthesis may be attributed to competition of immune response and gluconeogenesis.

• 디지털콘텐츠학회 논문지
• /
• 제16권3호
• /
• pp.457-462
• /
• 2015

논문에서 제안하고자 하는 하이브리드 화상통화 헬스케어 시스템은 여유로운 사용자보다는 일반 서민 계층과 취약 계층을 위한 서비스로 사용자가 자원봉사자 또는 보호자와의 커뮤니케이션이 되도록 하기 위한 시스템으로 거동이 불편하거나 바쁜 직장인의 부모님 등 사각지대에 놓인 사람들에게 필요한 말벗나누미를 통해 소외계층이 발생하는 부분을 줄여주는데 기술 개발을 목적으로 한다. 본 논문에서 제시하고자 하는 화상통화와 온도/습도/맥박 센서를 이용한 하이브리드 건강관리시스템은 센서와 소프트웨어 연동 및 통제, 데이터베이스를 이용해 말벗나누미 서비스를 위한 P2P 연결 정보를 저장하고, 건강 체크 데이터는 로컬에 저장할 수 있다. 무선 네트워크 환경에서 하이브리드 헬스케어 시스템은 독거노인들이 기본적 욕구인 대화를 이끌어 낼 수 있도록 하기 위한 시스템으로 사용자에게 편리한 UI 설계 및 소프트웨어를 개발하고, 노령화 시대에 따른 고령인구의 증가와 행복지수 증가에 따른 케어 시스템의 소비 증대를 위한 목적으로 한다.

• 한국임상수의학회지
• /
• 제37권5호
• /
• pp.235-241
• /
• 2020

We aimed to determine the effect of timed artificial insemination (TAI) protocols on the pregnancy rate per insemination and pregnancy loss compared with AI performed at detected estrus in dairy cows and Korean Hanwoo cattle under heat stress. In dairy cattle, 1,250 sets of data that underwent AI during heat stress (temperature-humidity index ≥ 72) were categorized according to their TAI protocols or as controls: 1) PGF_2α-36 h-estradiol benzoate (EB)-36 h-TAI (PG-EB group, n = 113); 2) GnRH-7 days-PGF_2α-56 h-GnRH-16 h-TAI (Ovsynch group, n = 455); or 3) GnRH-6 days-Ovsynch (G6G group, n = 136). The remaining cows underwent AI at detected estrus (AIDE group, n = 546). The probability of pregnancy per AI 45 days after AI was higher (P < 0.01) in the PG-EB (odds ratio [OR]: 1.68), Ovsynch (OR: 1.48), and G6G (OR: 1.79) groups than in the AIDE group. However, the prevalence of pregnancy loss between 30 and 45 days after AI did not differ among the groups. In Hanwoo cattle, 617 sets of data inseminated artificially under heat stress were categorized into AIDE (n = 281), PG-EB (n = 194), and combined Ovsynch or G6G (n = 142) groups. The probability of pregnancy per AI 45 days after AI and the prevalence of pregnancy loss between 30 and 45 days after AI did not differ among the groups. Thus, implementation of a TAI protocol (PG-EB, Ovsynch, or G6G) in dairy cows under heat stress improves the pregnancy rate per AI versus AIDE, whereas there is no beneficial effect of TAI on the pregnancy rate of Hanwoo cattle under heat stress.

• 한국철도학회논문집
• /
• 제13권6호
• /
• pp.552-558
• /
• 2010

철도차량의 승차감은 진동뿐만 아니라 소음, 냄새, 온도 등 많은 요인들에 의해 영향을 받지만 승객에 크게 영향을 주는 진동으로 평가하는 것이 일반적이다. 승차감은 승객이 느끼는 감정이므로 물리적인 가속도의 크기뿐만 아니라 진동에 대한 인간의 감응도(느낌)도 고려하여야 한다. 이러한 진동에 대한 인간의 감응도를 나타낸 것이 주파수 보정곡선이다. 따라서, 철도 차량의 승차감 평가에는 인간의 감응도가 고려된 주파수 보정 가속도를 필요로 한다. 철도차량의 승차감 평가는 많은 규격에 규정되어 있으나, 각각의 규격에 따라 서로 다른 주파수 보정 곡선을 제시하고 있다. 본 논문에서는 국제철도협회, 유럽표준위원회, 국제표준위원회에서 규정한 주파수 보정곡선에 대해 분석하고 그 차이점을 고찰한다. 또한, 주파수 보정곡선의 차이가 고속철도 차량의 승차감 평가에 미치는 영향을 실제의 시운전 시험을 통해 분석하고자 한다.

• Journal of Animal Science and Technology
• /
• 제60권11호
• /
• pp.28.1-28.6
• /
• 2018

Background: Preventing oxidative stress in heat stressed animals may be possible by increasing antioxidant defence via exogenous administration of antioxidant substrate and/or its precursors. The study aimed to investigate the effect of Soursop juice in mitigating oxidative stress induced by heat stress in rabbit. Methods: Sixty mixed breed rabbit bucks aged 12-18 months old with the average weight of $1826{\pm}8.35$ g/rabbit, randomly allotted to experimental treatments of four replicates each, in a completely randomized design during high-temperature humidity index in Ado Ekiti, Southwest Nigeria. Soursop juice (SSJ) was administered via oral drenched daily per kg body weight (BW), to designated treatment 1 to 5; $0.55mlkg^{-1}BW$ distilled water (control), $0.55mlkg^{-1}BW$ SSJ, $1.11mlkg^{-1}BW$ SSJ, $1.67mlkg^{-1}BW$ SSJ and $2.22mlkg^{-1}BW$ SSJ, respectively. Fastened blood samples were collected at days 28 and 56, and assay for serum protein, cholesterol, triglycerides, superoxide dismutase, catalase, reduced glutathione and lipid peroxidation using standard procedures. Result: Result revealed that SSJ demonstrated hypocholesterolemic effect in a dose-dependent manner throughout the study. Effect of chronic administration of SSJ to heat stressed rabbits proved beneficial, as SSJ reduced serum lipid peroxidation and enhanced antioxidant activity over 8 weeks. Conclusion: Administration of soursop juice to heat-stressed bucks at $2.22mlkg^{-1}BW$ offered optimum antioxidant defense against oxidative stress.

• Journal of Animal Science and Technology
• /
• 제63권6호
• /
• pp.1433-1442
• /
• 2021

In this study, Saccharomyces cerevisiae culture fluid (SCCF) has been added to a diet of lactating dairy cows to attempt to improve the ruminal fermentation and potentially increase the dry matter intake (DMI) and milk yield. This study was conducted to investigate the effects of SCCF on the milk yield and blood biochemistry in lactating cows during the summer. Twenty-four Holstein dairy cows were randomly assigned to one of four treatments: (1) total mixed ration (TMR-1) (Control); (2) TMR-1 supplemented with SCCF (T1); (3) TMR-2 (containing alfalfa hay) (T2); and (4) TMR-2 supplemented with SCCF (T3). SCCF (5 ml/head, 2.0×10⁷ CFU/mL) was mixed with TMRs daily before feeding to dairy cows. The mean daily temperature-humidity index (THI) during this trial was 76.92 ± 0.51 on average and ranged from 73.04 to 81.19. For particle size distribution, TMR-2 had a lower >19 mm fraction and a higher 8-9 mm fraction than TMR-1 (p < 0.05). The type of TMR did not influence the DMI, body weight (BW), milk yield and composition, or blood metabolites. The milk yield and composition were not affected by the SCCF supplementation, but somatic cell counts were reduced by feeding SCCF (p < 0.05). Feeding SCCF significantly increased the DMI but did not affect the milk yield of dairy cows. The NEFA concentration was slightly decreased compared to that in the control and T2 groups without SCCF. Feeding a yeast culture of S. cerevisiae may improve the feed intake, milk quality and energy balance of dairy cows under heat stress.

• Animal Bioscience
• /
• 제35권11호
• /
• pp.1800-1807
• /
• 2022

Objective: This study aimed to determine the effect of different cooling sessions (CSs) as a water conservation strategy on physiological, and production responses and welfare in Holstein Friesian cows during subtropical summer in Pakistan. Methods: Twenty-one cows were subjected to three CS in a completely randomized design. The treatments were: i) eleven hours continuous cooling with sprinklers - control (CNT), ii) four CS, and iii) two CS. The CNT represented the practices of the commercial dairy farms in the area, while the other CSs were used as water reduction strategies. Each CS lasted for 1 h with a 12 min cycle (3 min water on and 9 min off) with a sprinkler flow rate of 1.25 L/min. Results: The average temperature humidity index of the shed and the outside open area were 81.9 and 82.5, respectively. The results showed that both physiological responses were highest in the 2CS group followed by the CNT and the 4CS (p = 0.001). The CNT and 4CS groups had similar milk yield (p = 0.040). The 4CS group had more lying and eating times than the CNT and 2CS groups (p = 0.000). The cortisol level in the 2CS group was 2.0 and 2.2 ㎍/dL more than the CNT and the 4CS groups, respectively (p = 0.000). Conclusion: In conclusion, the 4CS was more efficient in cooling the cows and had better welfare, as it yielded similar milk yield, and better physiological responses than the CNT despite using 90% less water.

• Steel and Composite Structures
• /
• 제43권6호
• /
• pp.821-837
• /
• 2022

This research is devoted to study the effects of humidity and temperature on the bending behavior of functionally graded (FG) ceramic-metal porous plates resting on Pasternak elastic foundation using a quasi-3D hyperbolic shear deformation theory developed recently. The present plate theory with only four unknowns, takes into account both transverse shear and normal deformations and satisfies the zero traction boundary conditions on the surfaces of the functionally graded plate without using shear correction factors. Material properties of porous FG plate are defined by rule of the mixture with an additional term of porosity in the through-thickness direction. The governing differential equations are obtained using the "principle of virtual work". Analytically, the Navier method is used to solve the equations that govern a simply supported FG porous plate. The obtained results are checked by comparing the results determined for the perfect and imperfect FG plates with those available in the scientific literature. Effects due to material index, porosity factors, moisture and thermal loads, foundation rigidities, geometric ratios on the FG porous plate are all examined. Finally, this research will help us to design advanced functionally graded materials to ensure better durability and efficiency for hygro-thermal environments.