• 한국게임학회 논문지
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• 제13권3호
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• pp.85-94
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• 2013

본 논문에서는 광선 추적기법에서 그림자 검사의 연산량을 줄이는 기법을 제안한다. 그림자 검사는 부드러운 그림자와 같이 실감 있는 영상을 생성하는 경우 광선 추적기법 렌더링 과정 중 매우 큰 비중을 차지한다. 제안하는 방식은 전처리 단계에서 kd-tree를 생성하며 계산한 그림자 정보를 기반으로 렌더링 단계에서 그림자 검사의 컬링 여부를 판별하는 방식으로 기존 렌더링 과정에 작은 변경으로 적용가능하다. 기존의 방식들과 유사하게 광원과 기하학적 구조가 변하지 않는 정적 장면에 적합하다. 사이클 정확도를 갖는 시뮬레이터를 이용하여 제안하는 방법의 유효성을 검증하고 성능을 측정하였으며 실험 결과 제안하는 그림자 컬링 기법으로 최대 17%까지 줄일 수 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권1호
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• pp.11-15
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• 2002

The present investigation was undertaken to study the effects of non-genetic factors and association among replacement and lifetime production traits. The data on 542 Holstein Friesian cows maintained during 1975-98 at State Cattle Breeding Project, Sector III, Hisar, were utilized. The average sex-ratio, abnormal births, mortality, culling and replacement rates on total calf born and total female calf born basis were 51.62, 8.50, 17.52, 31.05, 22.78 and 51.41 per cent, respectively. The study revealed that a minimum of 4 to 5 progenies are required per cow over its lifetime to replace itself. It indicated that each cow should produce a minimum of 2 female calves during its life so as to replace herself before being lost. The least-squares means for productive herd life, longevity and lifetime production were $1439.32{\pm}87.64$ and $2419.18{\pm}8.25$ days and $11317.95{\pm}913.15kg$, respectively. The heritability estimates for all replacement traits were very low indicating that sire selection may bring no desirable change in these traits. Heritability estimates were $0.178{\pm}0.157$, $0.288{\pm}0.184$ and $0.096{\pm}0.195$ for corresponding lifetime production traits. Breeding values and ranking of sires were generated for replacement and lifetime production traits to estimate the rank correlations between these traits. Moderate desirable rank correlations were obtained between replacement rate and lifetime production traits indicating that sires proven on the basis of milk production are also expected to have better replacement rate.

• 한국환경농학회:학술대회논문집
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• 한국환경농학회 2009년도 정기총회 및 국제심포지엄
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• pp.220-227
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• 2009

For last about 10 years, the Republic of Korea experienced 3 times of outbreaks of highly pathogenic avian influenza (HPAI) from 10 December 2003 to 30 April 2004 (a total number of 19 outbreaks), 22 November 2006 to 6 March 2007 (a total number of 7 outbreaks), and 1 April 2008 to 12 May 2008 (a total number of 33 outbreaks). Among the totally 59 outbreaks, the infected premises included 35 chicken farms, 17 duck farms, 1 quail farm, and 6 farms rearing mixed species. Control measures were applied according to the HPAI standard operation procedure including depopulation of all infected and suspected flocks, movement restrictions, and disinfection of the infected farms within a 500-meter radius. Including movement restrictions, stringent control measures were additionally applied to two designated zones: the protection zone was an area within a 3-kilometer radius of the outbreak farm, and the surveillance zone was an area between a 3- to 10-kilometer radius of the outbreak farm. Farms with dangerous contacts and/or all of poultry within the protection zone was subjected to preemptive culling. Epidemiological investigations were also carried out including trace-back and trace-forward investigations to identify possible sources of spread and dangerous contact farms. Investigation teams conducted on-site examination of farm premises and facilities, interview with farm owner and staff, and review of records. Genetic and pathogenic characteristics of the virus isolates, and the results of the various surveillance activities were also analyzed. HPAI surveillance conducted in Korea includes passive surveillance of investigating notified cases, and active surveillance of testing high risk groups and areas. HPAI is a notifiable disease in Korea and all suspect cases must be reported to the veterinary authorities. Cases reported for other poultry diseases that require differential diagnosis are also tested for HPAI. Active surveillance includes annual testing of breeder duck farms, broiler duck farms and wild bird surveillance, which is concentrated during the autumn and winter. Surveillance activities conducted prior to the outbreaks have shown no evidence of HPAI infection in Korea.

• 한국동물위생학회지
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• 제42권4호
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• pp.183-191
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• 2019

Claw lesion is one of the major causes of lameness in sows and the lameness is one of the reasons for culling of sows from the swine herd. This survey was conducted on sows in total of 8 farms with a total of 684 pigs. The lesions observed in the study were horizontal and vertical claw cracks (CWH & CWV), differences in the length of toes (T) and/or in the length of dew claws (DC) according to crates, breeds and parity of sows. Scores of claw lesions were assigned on 0, 1, 2, and 3 at each foot depending on the severity of the claw lesions. The sows' parity was classified into 1 to 2, 3 to 4, 5 to 8. Prevalence rate of claw lesions in sows raised on punched plastic crate was higher than that in sows raised on tribar crate. In prevlence rate by breeds, inbreed Landrace sows showed higher than that of Yorkshire sows. According to 4 claw lesions, the length of DC was the highest at parity 3~4 and CWV was the lowest at parity 3~4 in F1 crossbred sows raised on punched plastic crates, respectively. In Yorkshire breeds raised on punched plastic crates, the length of DC at parity 5~8 was the lowest and CWH was the highest at parity 3~4, respectively. In Landrace breeds raised on tribar crates, CWH was the highest at parity 1~2 and CWV was the lowest at parity 3~4, respectively. The high parity in F1 crossbred sows showed high prevalence rate of claw lesions than that of low parity and other inbreed sows, respectively. These results may be useful as elementary data in establishment of welfare quality protocol and preventive measures to reduce economic losses from craw lesions in sows.

• Asian-Australasian Journal of Animal Sciences
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• 제27권10호
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• pp.1499-1512
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• 2014

The purposes of this study are to assess pig farmers' preference for highly pathogenic porcine reproductive and respiratory syndrome (PRRS) vaccine, and estimate the cost and benefit of PRRS vaccination in Vietnam. This study employed an integrated epidemiological and economic analysis which combined susceptible-infectious-recovered (SIR) model, choice experiment (CE) and cost-benefit analysis (CBA) together. The result of SIR model showed the basic reproduction number ($R_0$) of PRRS transmission in this study is 1.3, consequently, the optimal vaccination percentage is 26%. The results of CE in this study indicate that Vietnam pig farmers are showing a high preference for the PRRS vaccine. However, their mean willingness to pay is lower than the potential cost of PRRS vaccine. It can be considered to be one of the reasons that the PRRS vaccination ratio is still low in Vietnam. The results of CBA specified from the whole society's point of view (Social perspective), the benefits of PRRS vaccination are 2.3 to 4.5 times larger than the costs. To support policy making for increasing the PRRS vaccination proportion, this study indicates two ways to increase the vaccination proportion: i) decrease vaccine price by providing a subsidy, ii) provide compensation of culling only for PRRS vaccinated pigs.

• Asian-Australasian Journal of Animal Sciences
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• 제26권3호
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• pp.303-308
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• 2013

Subfertility problems are encountered frequently in the cattle and buffalo bulls commercially maintained for semen production in dairy farms and under field conditions for natural insemination. Reports are scarce on the incidence of subfertility in breeding bulls, especially in India. The objective of the present study was to assess the incidence of the male reproductive anomalies leading to disposal of bovine bulls at GADVASU dairy farm, Ludhiana, Punjab (India). Data on frequency of various subfertility and disposal pattern of bulls maintained at the dairy farm, GADVASU, were collected for 12 yrs (1999 to 2010) and compiled from different record registers. Percentage of bulls that produced freezable semen (out of reserved ones) was less in cattle (25.641%) as compared to that of buffalo (30.4%). Various subfertility traits like poor libido and unacceptable seminal profile were found to be the significant reasons (p<0.01) for culling of the breeding bulls. Inadequate sex drive and poor semen quality were the main contributing factors for bull disposal in cattle whereas poor semen freezability was most frequently observed in buffalo bulls. All the male reproductive traits were significantly different (p<0.05) for the periods of birth, except for semen volume, initial motility (IM), age at last semen collection (ALSC) and age at disposal. The ages at first and last semen collection as well as freezing (i.e. AFSC, ALSC and AFSF, ALSF, respectively) and age at disposal (AD) were higher in buffalo. The spermatological parameters and semen production period (SPP) were higher in cattle. The age at first semen donation and breeding period could be reduced by introducing the bulls to training at an early age. The results revealed an increasing trend in individual motility (IM) while semen volume, AFSC, AFSF, AD, FSPP, SPP, ALSC and ALSF showed a decreasing, however, not a definite trend, over the periods. The semen donation traits like, AFSF, of the cattle and buffalo bulls could be predicted from the AFSC, using prediction equation derived in the present study.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.101-104
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• 2007

MFC는 플레이어 오브젝트를 중심으로 영역을 만들어 상대 오브젝트의 유무를 판단한다. 그러나 게임에서는 상관없는 오브젝트들까지 모두 탐색하여 게임의 속도를 저하시키고 위험성을 인식하는 단점이 발생한다. 본 논문에서는 이러한 단점을 보완하기 위하여 MFC를 이용할 때 플로킹의 회피규칙을 npc 오브젝트에게 적용 하였다. 따라서 npc 오브젝트는 시야의 개념을 가지게 되고 게임의 속도 저하를 막을 수 있는 방법을 제안하였다. 이때 제안된 2가지 조건을 만족해야 한다. 제안한 방법은 향후 3차원 FPS 게임의 발전에 주요한 역할을 할 것이다.

• 한국동물위생학회지
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• 제38권4호
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• pp.221-225
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• 2015

The bacterium causing Johne's disease (JD), Mycobacterium avium subspecies paratuberculosis (MAP), is distributed worldwide and causes progressive intestinal disease, also known as paratuberculosis, in domestic and exotic ruminants, including cattle. The subclinical form of this disease results in progressive weight loss, reduced milk production, lower slaughter value, and premature culling, with possible impacts on fertility and udder health. Eventually, infection can lead to the clinical form that manifests chronic diarrhea, emaciation, debilitation, and eventual death. JD is a major cause of economic loss in cattle industry. In this study, serological testing was conducted by ELISA to determine the prevalence of MAP in Korean native cattle of Jeju during the duration of 2010 to 2013. A total of 5,150 blood sera were collected in 111 farms and the samples were classified into four different age groups for MAP; group 1 (2 years or less), group 2 (2~4 years), group 3 (5~7 years), and group 4 (over 8 years). Overall seroprevalence of MAP was 5.2% (269/5,150), and annually from 2010 to 2013, they were 11.6% (106/915), 2.1% (10/474), 5.5% (89/1,627), and 3.0% (64/2,134), respectively. Also, the prevalence rates was determined by age groups: 48 of group 1 (17.8%), 154 of group 2 (57.3%), 48 of group 3 (17.8%), and 19 of group 4 (7.1%) were seropositive for MAP. Although seropositive samples were found in all age groups, the highest seroprevalence was found in group 2. This study showed that during the investigation the seroprevalence of MAP tended to decrease.

• 대한수의학회지
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• 제53권1호
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• pp.19-23
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• 2013

This study was carried out to evaluate the diagnosis of acute clinical mastitis (ACM) which was based on the vital signs and complete blood count (CBC) tests in dairy cows. Twenty eight dairy cows diagnosed with ACM, were selected for the study between Jan 2003 and July 2006 in the National Institute of Animal Science. Based on their vital signs (rectal temperature, depression, rumen contraction and, dehydration status), ACM was divided into three different classes; mild, moderate and severe forms. In addition, ACM cows were subjected to CBC tests for further diagnosis of ACM. Of the 27 dairy cows diagnosed with ACM, 3 cows were determined to have a mild form, while moderate and sever forms were each observed in twelve cows. Among of them, 4 cows died, 5 cows were culled and 18 cows were recovered. In the mild form, all haematological parameters were comparable with normal values. However, leukopenia, due to neutropenia and lymphocytopenia, appeared characteristically in the moderate and severe forms. Using the observation of vital signs in conjunction with CBC tests, the diagnosis of ACM is more accurate, and is helpful in making decisions of whether treatment or culling of dairy cows infected with ACM is most appropriate.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2007년도 학술대회 3부
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• pp.306-317
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• 2007

We present an interactive and accurate collision detection algorithm for deformable, polygonal objects based on the streaming computational model. Our algorithm can detect all possible pairwise primitive-level intersections between two severely deforming models at highly interactive rates. In our streaming computational model, we consider a set of axis aligned bounding boxes (AABBs) that bound each of the given deformable objects as an input stream and perform massively-parallel pairwise, overlapping tests onto the incoming streams. As a result, we are able to prevent performance stalls in the streaming pipeline that can be caused by expensive indexing mechanism required by bounding volume hierarchy-based streaming algorithms. At run-time, as the underlying models deform over time, we employ a novel, streaming algorithm to update the geometric changes in the AABB streams. Moreover, in order to get only the computed result (i.e., collision results between AABBs) without reading back the entire output streams, we propose a streaming en/decoding strategy that can be performed in a hierarchical fashion. After determining overlapped AABBs, we perform a primitive-level (e.g., triangle) intersection checking on a serial computational model such as CPUs. We implemented the entire pipeline of our algorithm using off-the-shelf graphics processors (GPUs), such as nVIDIA GeForce 7800 GTX, for streaming computations, and Intel Dual Core 3.4G processors for serial computations. We benchmarked our algorithm with different models of varying complexities, ranging from 15K up to 50K triangles, under various deformation motions, and the timings were obtained as 30~100 FPS depending on the complexity of models and their relative configurations. Finally, we made comparisons with a well-known GPU-based collision detection algorithm, CULLIDE [4] and observed about three times performance improvement over the earlier approach. We also made comparisons with a SW-based AABB culling algorithm [2] and observed about two times improvement.