• Communications for Statistical Applications and Methods
• /
• 제25권2호
• /
• pp.185-197
• /
• 2018

Measuring market fear is an important way of understanding fundamental economic phenomena related to financial crises. There have been several approaches to measure market fear or panic level in a financial market. Recently, herd behavior has gained its popularity as important economic phenomena explaining the fear in the financial market. In this paper, we investigate herd behavior in global stock markets with a focus on intercontinental comparison. While various risk measures are available for the detection of herd behavior in the market, we use the standardized herd behavior index in Dhaene et al. (Insurance: Mathematics and Economics, 50, 357-370, 2012b) and Lee and Ahn (Dependence Modeling, 5, 316-329, 2017) for the comparison of herd behaviors in global stock markets. A global stock market data from Morgan Stanley Capital International is used to study herd behavior especially during periods of financial crises.

• Journal of the Korean Data and Information Science Society
• /
• 제22권6호
• /
• pp.1199-1215
• /
• 2011

Relaxing an unrealistic assumption of a representative percolation model, this paper demonstrates that herd behavior leads to a high increase in volatility but not trading volume, in contrast with information flows that give rise to increases in both volatility and trading volume. Although detecting herd behavior has posed a great challenge due to its empirical difficulty, this paper proposes a new methodology for detecting trading days with herding. Furthermore, this paper suggests a herd-behavior-stochastic-volatility model, which accounts for herding in financial markets. Strong evidence in favor of the model specification over the standard stochastic volatility model is based on empirical application with high frequency data in the Korean equity market, strongly supporting the intuition that herd behavior causes excess volatility. In addition, this research indicates that strong persistence in volatility, which is a prevalent feature in financial markets, is likely attributed to herd behavior rather than news.

• Journal of Animal Science and Technology
• /
• 제46권5호
• /
• pp.773-782
• /
• 2004

본 연구는 산차와 비유기가 다양한 Holstein 종 56두를 사용하여 사료섭취량과 에너지요구 량을 근거로 개체별 사료에너지요구량의 서열을 설정하고, 이를 3개 우군으로 나누어 각 우군의 상반평균치에 기준하여 자가배합사료(herdmix ration)를 조제한 후 이것을 이용한 사양체계가 비유기 및 산차에 미치는 영향을 관행 사양체계와 switch-over method로 비교하였다. 자가배합사료 급여체계는 전 비유기 동안 산유량과 유지율을 증진시켰으며(P<0.05), 산차별 생산능력도 모든 산차에서 향상되었다(P<0.05). 비유단계별 성적에서는 비유초기와 중기에서 Herd-mix구의 설제산유량(AMY) 및 지방보정유량(FCM)이 유의적으로 증가하였으나(P<0.05) 유지율은 유의차가 없었다. 비유말기에는 AMY, 유지율 및 FCM 모두 Herd-mix구가 관행구에 비하여 증가하였으며 특히 유지율과 FCM이 현저하게 증가하였다(P<0.01). Herd-mix구와 관행구의 FCM 비유지속성은 각각 93.24%와 92.69%로서 Herd-mix구의 비유지속성이 높았으며 비유곡선의 형태도 이상적 추세를 보였다. 유대와 사료비를 고려한 조수익을 산출한 결과 Herd-mix구가 관행구보다 40% 높았다. 결론적으로, 본 연구는 젖소의 에너지요구량과 사료 에너지 농도를 정확히 평가하여 우군을 편성한 후 그 상반평균을 배합목표로 설정하고 사용할원료에 대한 실질적인 평가를 근거로 배합비를 설정하는 것이 산유능력을 향상시킴과 동시에 경제적으로 유려하다는 사실을 입증하였다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
• /
• 제30권2호
• /
• pp.7-14
• /
• 2024

Purpose: This study aims to examine the trends in healthcare architecture research by analyzing papers published in KIHA (Journal of the Korea Institute of Healthcare Architecture) and HERD (Health Environments Research and Design Journal) in the USA. The analysis categorizes these papers into Evidence-Based Design (EBD) and non-EBD research from a comparative perspective. Methods: A systematic literature review was conducted on 370 papers published in KIHA and 399 papers published in HERD from 2007 to 2022. The research trends were analyzed based on the researchers' fields of study, research focus, and research attributes. Results: The findings indicate that HERD involves researchers from 43 different fields, whereas KIHA involves researchers from 16 fields, indicating less diversity. HERD predominantly includes interdisciplinary and empirical studies, while KIHA primarily features theoretical and single-discipline studies. Papers in HERD generally demonstrate a higher level of evidence compared to those in KIHA. Implications: Direct comparisons should be approached with caution due to the differing contexts of healthcare architecture research in the two countries. The methodological efforts in HERD and the functional analysis results in KIHA provide valuable references for the future direction of healthcare architecture research. Expanding collaborative and interdisciplinary research involving various professionals is essential to advance the field.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권5호
• /
• pp.661-668
• /
• 2007

Data on 1,037 Nili-Ravi buffaloes from four institutional herds were used to study lifetime milk yield, herd life, productive life and breeding efficiency. A general linear model was used to study the environmental effects while an animal model having herd, year of birth and age at first calving (as covariate) along with random animal effect was used to estimate breeding values. The lifetime milk yield, herd life, productive life and breeding efficiency averaged $7,723{\pm}164$ kg, $3,990{\pm}41$ days, $1,061{\pm}19$ days and 64 percent, respectively. All the traits were significantly (p<0.01) affected by the year of birth and herd of calving, while the herd life was also affected (p<0.01) by the age at first calving. The heritabilities for lifetime milk yield, herd life, productive life and breeding efficiency were $0.093{\pm}0.056$, $0.001{\pm}0.055$, $0.144{\pm}0.079$ and 0.001, respectively. The definition for productive life, where each lactation gets credit upto 10 months had slightly better heritability and may be preferred over the definition where no limit is placed on lactation length. The genetic correlation between productive life and lifetime milk yield was low but high between productive life and herd life. The selection for productive life will increase herd life while lifetime milk yield will also improve. The overall phenotypic trend during the period under the study was negative for lifetime milk yield (-280 kg/year), herd life (-93 days), productive life (-42 days/year) and breeding efficiency (-0.36 percent/year), whereas the genetic trend was positive for lifetime milk yield (+15 kg/year) and productive life (+4 days/year).

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권2호
• /
• pp.179-184
• /
• 2005

First lactation records (174) of Jersey${\times}$Sahiwal and Holstein Friesian${\times}$Sahiwal half breds under 9 sires maintained at Chandra Shekher Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, India from 1975-1983, were used to estimate the genetic parameters and to predict herd life milk yield and average milk yield per day of herd life from first lactation traits. The traits included were: age at first calving, first service period, first lactation period, first calving interval, first lactation milk yield, milk yield per day of first calving interval, herd life milk yield, herd life and average milk yield per day of herd life. Most of the production and reproduction traits were found to have positive and significant correlations between them on genetic as well as phenotypic scales. Total twelve regression equations were fitted. The prediction equation of herd life milk yield in both the genetic groups showed linear relationship with AFC, FSP, FLP, FLMY and MY/DCI and was apparent and significant. Similarly, polynomials for milk yield per day of herd life for J${\times}$S and HF${\times}$S half breds also showed linear trend, which was found highly significant. The highest and lowest $R^2$ values were found for FCI and AFC, respectively.

• 한국가축번식학회지
• /
• 제22권4호
• /
• pp.367-373
• /
• 1998

본 조사 연구는 사육규모에 따른 한우 번식우의 초종부, 초임 및 초산일령과 분만 후 발정재귀일수, 수태당 종부회수, 분만 후 수태일수, 분만간격 등을 검토하기 위하여 1996년 1월부터 1997년 12월까지 20농가에서 사육중인 한우 성빈우 670두를 대상으로 조사를 수행하였다. 1. 사육규모에 따른 한우 미경산우의 초종부일령은 평균 443.0일이었고 사육규모별로는 1규모, 2규모 및 3규모가 각각 437.9일, 425.5일 및 452.9일로 사육규모간에 유의적인 차이는 인정되지 않았다 (p＞0.05). 2. 사육규모에 따른 한우 미경산우의 초임일령은 평균 460.0일이었고 사육규모별로는 1규모, 2규모 및 3규모가 각각 452.8일, 438.4일 및 467.1일로 사육규모간에 유의적인 차이는 인정되지 않았다(p＞0.05). 3. 사육규모에 따른 한우 미경산우의 초산일령은 평균 746.6일이었고 사육규모별로는 1규모, 2규모 및 3규모가 각각 741.2일, 730.2일 및 755.9일로 사육규모간에 유의적인 차이는 인정되지 않았다(p＞0.05). 4. 사육규모에 따른 분만후 발정재귀일수는 평균 70.1일이었고 사육규모별로는 l규모, 2규모 및 3규모가 각각 82.1일, 74.1일 및 64.8일로 3규모가 가장 짧았고 1규모가 가장 긴 경향을 나타내었다(p＜0.05). 5. 사육규모에 따른 수태당 종부회수는 평균 1.53회였고 사육규모별로는 1규모, 2규모 및 3규모가 각각 1.54회, 1.61회 및 1.48회로 사육규모간에 유의적인 차이는 인정되지 않았다 (p＞0.05). 6. 사육규모에 따른 분만 후 수태일수는 평균 91.2일이었고 사육규모별로는 1규모, 2규모 및 3규모가 각각 115.6일, 99.1일 및 80.6일로 규모가 증가함에 따라 짧아지는 경향을 나타내었다 (p＜0.05). 7. 사육규모에 따른 분만간격은 평균 375.3일이었으며, 사육규모별로는 1규모, 2규모 및 3규모가 각각 389.5일, 383.0일 및 367.4일로 3규모가 가장 짧았고 1규모가 가장 긴 경향을 나타내었다 (p<0.05).

• 대한수의학회지
• /
• 제46권2호
• /
• pp.159-164
• /
• 2006

A stochastic simulation model incorporated with Reed-Frost approach was derived for evaluating diagnostic performance of a test used for a screening program of an infectious disease. The Reed-Frost model was used to characterize the within-herd spread of the disease using a hypothetical example. Specifically, simulation model was aimed to estimate the number infected animals in an infected herd, in which imperfect serologic tests are performed on samples taken from herds and to illustrate better interpreting survey results at herd-level when uncertainty inevitably exists. From a risk analysis point of view, model output could be appropriate in developing economic impact assessment models requiring probabilistic estimates of herd-level performance in susceptible populations. The authors emphasize the importance of knowing the herd-level diagnostic performance, especially in performing emergency surveys in which immediate control measures should be taken following the survey. In this context this model could be used in evaluating efficacy of a survey program and monitoring infection status in the area concerned.

• 유통과학연구
• /
• 제20권1호
• /
• pp.77-85
• /
• 2022

Purpose: The Covid-19 pandemic has triggered several herd purchase behaviors, and online shopping has been considered a health-related preventative behavior. Thisstudy aimsto the relative impact of health threat beliefs concerning Covid-19 (perceived susceptibility and perceived severity) and herd mentality on consumers' online shopping post-adoption disconfirmation and continuance intention of online shopping. Research design, data and methodology: An internet survey was conducted with Vietnamese consumers, and upon screening, usable data of 292 responses were analyzed using PLS-SEM. Results showed that while herd mentality positively affects disconfirmation, health threat beliefs including perceived susceptibility and perceived severity of Covid-19 do not. Results: Results also provided further support for the notion that disconfirmation is a crucial determinant of post-adoption continuance intention. Moreover, herd mentality also has a significantly negative influence on online shopping post-adoption continuance intention. Conclusions: The research provides evidence supporting the role of herd mentality and post-adoption disconfirmation in driving consumers' intention to continue online shopping. However, the research shows that neither the perceived susceptibility of Covid-19 nor the perceived severity of Covid-19 has significant impact on post-adoption disconfirmation, adding mixed evidence to the application of health belief theory in technology (such as online shopping) adoption.

• Asian-Australasian Journal of Animal Sciences
• /
• 제28권7호
• /
• pp.1044-1052
• /
• 2015

The aim of this modelling study was to investigate the effect of large herd size (and land areas) on walking distances and milking interval (MI), and their impact on milk yield and economic penalties when 50% of the total diets were provided from home grown feed either as pasture or grazeable complementary forage rotation (CFR) in an automatic milking system (AMS). Twelve scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as 'moderate'; optimum pasture utilisation of 19.7 t DM/ha, termed as 'high') and 2 rates of incorporation of grazeable complementary forage system (CFS: 0, 30%; CFS = 65% farm is CFR and 35% of farm is pasture) were investigated. Walking distances, energy loss due to walking, MI, reduction in milk yield and income loss were calculated for each treatment based on information available in the literature. With moderate pasture utilisation and 0% CFR, increasing the herd size from 400 to 800 cows resulted in an increase in total walking distances between the parlour and the paddock from 3.5 to 6.3 km. Consequently, MI increased from 15.2 to 16.4 h with increased herd size from 400 to 800 cows. High pasture utilisation (allowing for an increased stocking density) reduced the total walking distances up to 1 km, thus reduced the MI by up to 0.5 h compared to the moderate pasture, 800 cow herd combination. The high pasture utilisation combined with 30% of the farm in CFR in the farm reduced the total walking distances by up to 1.7 km and MI by up to 0.8 h compared to the moderate pasture and 800 cow herd combination. For moderate pasture utilisation, increasing the herd size from 400 to 800 cows resulted in more dramatic milk yield penalty as yield increasing from c.f. 2.6 and 5.1 kg/cow/d respectively, which incurred a loss of up to $AU 1.9/cow/d. Milk yield losses of 0.61 kg and 0.25 kg for every km increase in total walking distance (voluntary return trip from parlour to paddock) and every one hour increase in MI, respectively. The high pasture utilisation combined with 30% of the farm in CFR in the farm increased milk yield by up to 1.5 kg/cow/d, thereby reducing loss by up to $0.5/cow/d (c.f. the moderate pasture and 800 cow herd scenario). Thus, it was concluded that the successful integration of grazeable CFS with pasture has the potential to improve financial performance compared to the pasture only, large herd, AMS.