• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.755-768
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• 2002

We investigate the effect of the data skew of join attributes on the performance of a pipelined multi-way hash join method, and propose two new hash join methods with load balancing capabilities. The first proposed method allocates buckets statically by round-robin fashion, and the second one allocates buckets adaptively via a frequency distribution. Using hash-based joins, multiple joins can be pipelined so that the early results from a join, before the whole join is completed, are sent to the next join processing without staying on disks. Unless the pipelining execution of multiple hash joins includes some load balancing mechanisms, the skew effect can severely deteriorate system performance. In this paper, we derive an execution model of the pipeline segment and a cost model, and develop a simulator for the study. As shown by our simulation with a wide range of parameters, join selectivities and sizes of relations deteriorate the system performance as the degree of data skew is larger. But the proposed method using a large number of buckets and a tuning technique can offer substantial robustness against a wide range of skew conditions.

• The KIPS Transactions:PartA
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• v.14A no.7
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• pp.443-450
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• 2007

Performance scalability and storage scalability become important in a large scale cluster of wireless internet proxy cache servers. Performance scalability means that the whole performance of the cluster increases linearly according as servers are added. Storage scalability means that the total size of cache storage in the cluster is constant, regardless of the number of cache servers used, if the whole cache data are partitioned and each partition is stored in each server, respectively. The Round-Robin based load balancing method generally used in a large scale server cluster shows the performance scalability but no storage scalability because all the requested URL data need to be stored in each server. The hashing based load balancing method shows storage scalability because all the requested URL data are partitioned and each partition is stored in each server, respectively. but, it shows no performance scalability in case of uneven pattern of client requests or Hot-Spot. In this paper, we propose a novel dynamic hashing method with performance and storage scalability. In a time interval, the proposed scheme keeps to find some of requested URLs allocated to overloaded servers and dynamically reallocate them to other less-loaded servers. We performed experiments using 16 PCs and experimental results show that the proposed method has the performance and storage scalability as different from the existing hashing method.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.551-560
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• 2018

Bellflower root (Platycodon grandiflorum), which belongs to the Campanulaceae family, is a perennial grass that grows naturally in Korea, northeastern China, and Japan. Bellflower is widely consumed as both food and medicine owing to its high nutritional value and potential therapeutic effects. Since foodborne disease outbreaks often come from vegetables, understanding the public health risk of microorganisms on fresh vegetables is pivotal to predict and prevent foodborne disease outbreaks. We investigated the microbial communities on the bellflower root (n = 10). 16S rRNA gene amplicon sequencing targeting the V6-V9 regions of 16S rRNA genes was conducted via the 454-Titanium platform. The sequence quality was checked and phylogenetic assessments were performed using the RDP classifier implemented in QIIME with a bootstrap cutoff of 80%. Principal coordinate analysis was performed using the weighted Fast UniFrac distance. The average number of sequence reads generated per sample was 67,192 sequences. At the phylum level, bacterial communities from the bellflower root were composed primarily of Proteobacteria, Firmicutes, and Actinobacteria in March and September samples. Genera Serratia, Pseudomonas, and Pantoea comprised more than 54% of the total bellflower root bacteria. Principal coordinate analysis plots demonstrated that the microbial community of bellflower root in March samples was different from those in September samples. Potential pathogenic genera, such as Pantoea, were detected in bellflower root samples. Even though further studies will be required to determine if these species are associated with foodborne illness, our results indicate that the 16S rRNA gene-based sequencing approach can be used to detect pathogenic bacteria on fresh vegetables.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1992.10a
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• pp.113-116
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• 1992

소음의 발생 원인은 공기역학적 측면과 구조적 측면으로 나누어지는데, 실제 로는 유동장에서 발생되는 음원과 구조물에서 발생되는 진동과의 상호 간섭 에 의해 보다 복잡한 형태로 발생된다. 음장 문제를 두가지 범주로 구분하면 첫째는 음원과 구조물과의 상호교란에 의한 산란문제(Scattering)와 둘째로 구조물의 자체 진동에 의한 음의 전파현상과 구조물내부에 회전체와 같은 음원이 존재하는 경우에 음의 전파를 관측하는 방사문제(Radiation)가 있다. 실제로 산업용 터빈이나 비행기 엔진 흡입구에서 발생되는 소음, 또는 자동 차의 배기구를 통해 발생되는 소음 그리고 엔진의 진동에 의한 구조적 소음, 기타 가전제품의 회전체(Fan & Motor)에 의한 소음은 방사(Radiation)의 문 제로서 중요 관심 과제이다 수치적 기법으로 근래에 많이 사용하는 방법으 로 BEM(경계요소법), FEM(유한요소법), FDM(유한차분법)이 있는데 본 연 구에서는 유한요소법을 이용하기로 한다. 지금까지는 주로 BEM을 통해서 Far-Field의 음향장을 해석하였지만 복잡한 형상을 갖는 구조물내부에서의 음향장 변화나 구조물 내부에 음원이 존재하는 경우 또는 구조물 자체가 갖 는 물리적 특성치 변화 즉 물체표면에서의 부분 진동문제의 음향장 해석에 있어서 가장 잘 대체해 나갈 수 있는 방법이 유한 요소법이라고 여겨진다. 본 연구에서는 2차원 또는 기하학적으로 축대칭인 3차원 Duct내부에 음원이 존재하는 경우 음원전파에 따른 Near-field와 far-field에서 음의 방향성을 예측하기 위해 먼저 기본적인 유한요소법에 의한 Robin 경계조건을 사용하 여 계산된 결과와 Infinite Element를 도입하여 계산할 결과를 비교하여, Infinite Element가 보다 효율적이며 타당한 결과를 얻음을 확인해 보기로 한다.다 복합적인 측면에서 치료에 임하여야 할 것으로 사료된다. with such configuration.trap with 2.88[eV] deep of injected space charge from the chathode in the crystaline regions. The origin of ${\alpha}$$_2$ peak was regarded as the detrapping process of ions trapped with 0.9[eV] deep originated from impurity-ion remained in the specimen during production process of the material, in the crystalline regions. The origin of ${\beta}$ peak was concluded to be due to the depolarization process of "C=0"dipole with the activation energy of 0.75[eV] in the amorphous regions. The origin of ${\gamma}$ peak was responsible to the process combined with the depolarization of "CH$_3$", chain segment, with the activation energy of carriers from the shallow trap with 0.4[eV], in he amorphous regions.의 증발산율은 우기의 기상자료를 이용하여 구한 결과 0.05 - 0.10 mm/hr 의 범위로서 이로 인한 강우손실량은 큰 의미가 없음을 알았다.재발이 나타난 3례의 환자

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5401-5406
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• 2014

Background: Cancer is the leading cause of mortality around the world. However, the majority of cancers occur as a result of modifiable risk factors; hence public awareness of cancer risk factors is crucial to reduce the incidence. The objective of this study was to identify the level of public awareness of cancer risk factors among the adult Omani population. Materials and Methods: A community based survey using the Cancer Awareness Measure (CAM) questionnaire was conducted in three areas of Oman to measure public awareness of cancer risk factors. Omani adults aged 18 years and above were invited to participate in the study. SPPSS (ver.20) was used to analyse the data. Results: A total of 384 participated from 500 invited individuals (response rate =77%). The majority of respondents agreed that smoking cigarettes (320, 83.3%), passive smoking (279, 72.7%) and excessive drinking of alcohol (265, 69%) are risks factors for cancer. However, fewer respondents agreed that eating less fruit and vegetables (83, 21.6%), eating more red or processed meat (116, 30.2%), being overweight (BMI> 25) (123, 32%), doing less physical exercise (119, 31%), being over 70 years old (72, 18.8%), having a close relative with cancer (134, 34.9%), infection with human papilloma virus (HPV) (117, 30.5%) and getting frequent sunburn during childhood (149, 38.8%) are risk factors for cancer. A significant association was found between participant responses and their educational level. The higher the educational level, the more likely that respondents identified cancer risk factors including smoking (p<0.0005), passive smoking (p= 0.007), excessive drinking of alcohol (p<0.0005), eating less fruit and vegetables (p= 0.001) and infection with HPV (p<0.0005). Conclusions: The majority of respondents in this study in Oman were not aware of the common risk factors for cancer. It may be possible to reduce the incidence of cancers in Oman by developing strategies to educate the public about these risk factors.

• Journal of Korean Academy of Nursing
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• v.30 no.2
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• pp.437-451
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• 2000

The purpose of this study was to estimate the forecast of bed demand for institutional long-term care for the elderly persons in Taegu Metropolitan City. The study subject was the total 1,877 elderly persons over age 65 living in Taegu. Among them 1,441 elderly persons were sampled from community and 436 were from the elderly admitted 5 general hospitals. Data collection was carried out by interview from 25 August to 25 December 1997. The measuring instrument of this study was the modified tool of CARE, MAI, PCTC, and ADL which were examined for validity and reliability. In order to forecast bed demand of Nursing Home, this study revised prediction techniques suggested by Robin. The results were as follows : 1. OLDi of Taegu City were 122,202 by the year 1998 and number of Low-Income Elderly Persons were 3,210. 2. The Level I : Senior Citizen Home $ADEMi=\frac{AQi * ASTAYi}{365 * AOCUi}$. AQi = OLDi * LADLi * NASi * ALONi * LIADLi * AUTILi. Predicted number of bed demand for Home Based. Elderly Persons were 4,210 and Low-Income Elderly Persons were 1,081 and Total Elderly Persons were 5,291 by the year 1998, 6,343 by the year 2000 and 8,351 by the 2005. 3. The Level II : Nursing Home $BDEMi=\frac{(BQ1i+BQ2i) * BSTAYi}{365 * BOCUi}$. BQ1i = OLDi * HADLi * ALONi * HIADLi BQ2i = OLDi * HADLi * FAMi * OBEDi Predicted number of demand for Total Elderly Persons were 668 by the year 1998, 802 by the year 2000 and 1,055 by the 2005. 4. The Level III : Nursing Home $CDEMi=\frac{COLDi * HDISi * CUTILi * CSTAYi}{365 * COCUi}+OQi/10$ Predicted number of demand for Total Elderly Persons were 1,899 by the year 1998, 2,311 by the year 2000 and 3,003 by the 2005. 5. Predicted number of bed demand of long-term care facilities in the year 1998 according to Levels were 4.3% among elderly persons in Taegu by Level I, 0.5% by Level II and 1.5% by Level III. Number of elderly persons in current long-term care facilities were 458 in LevelI I,284 in Level II. 6. Deficit number of bed demand of long-term care facilities were 4,833 in Level I, 384 in Level II, 1,899 in Level III for the elderly persons in Taegu Metropolitan City.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.81-85
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• 2015

Since the banning of antibiotic growth promoters (AGPs), the death of livestock has been increased, thus there is a strong demand for AGP-alternatives. Modulation of gut microbiota has been reported to affect host physiological functions and suggested to be a novel approach for developing AGP-alternatives. However, little has been understood about livestock gut microbiota compared to that of humans. We conducted preliminary study provide fundamental information regarding to regional differences in swine gut microbiota. Swine fecal samples were obtained from farms in Jeju (n=40), Gwangju (n=28), and Haenam (n=30). MiSeq was used to sequence 16S rRNA V4 region, and Mothur pipeline (Schloss et al., 2009) was used for data processing. A total of 5,642,125 reads were obtained and 3,868,143 reads were remained after removing erroneous reads. Analysis of taxonomic composition at the phylum level indicated greater abundance of Firmicutes among Jeju swine, and cluster analysis of distribution of operational taxonomic units also showed regional differences among swine gut microbiota. In addition, correlation analysis between non-metric multidimensional scaling and abundance of phyla suggested that the phyla Actinobacter, Verrucomicrobia, Firmicutes, and Fibrobacteres were driving factors for the regional differences. Livestock gut microbiota may be affected by diet and practices in farms. Our results indicated significant regional differences in swine gut microbiota, suggesting that future livestock gut microbiota studies should be designed with the regional differences in mind.

• Journal of Internet Computing and Services
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• v.6 no.2
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• pp.69-84
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• 2005

As the Internet users are increasing rapidly, a cluster web server system is attracted by many researchers and Internet service providers. The cluster web server has been developed to efficiently support a larger number of users as well as to provide high scalable and available system. In order to provide the high performance in the cluster web server, efficient load distribution is important, and recently many content-aware request distribution techniques have been proposed. In this paper, we propose a new content-aware load balancing technique that can evenly distribute the workload to each node in the cluster web server. The proposed technique is based on the hash histogram transformation, in which each URL entry of the web log file is hashed, and the access frequency and file size are accumulated as a histogram. Each user request is assigned into a node by mapping of (hashed value-server node) in the histogram transformation. In the proposed technique, the histogram is updated periodically and then the even distribution of user requests can be maintained continuously. In addition to the load balancing, our technique can exploit the cache effect to improve the performance. The simulation results show that the performance of our technique is quite better than that of the traditional round-robin method and we can improve the performance more than $10\%$ compared with the existing workload-aware load balancing(WARD) method.

• Journal of Genetic Medicine
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• v.8 no.1
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• pp.53-57
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• 2011

Purpose: Wilson disease is an autosomal recessive disorder which causes excessive copper accumulation in the hepatic region. So far, ATP7B gene is the only disease-causing gene of Wilson disease known to date. However, ATP7B mutations have not been found in ~15% of the patients. This study was performed to identify any causative gene in Wilson disease patients without an ATP7B mutation in either allele. Materials and Methods: The sequence of the coding regions and exon-intron boundaries of the five ATP7B-interacting genes, ATOX1, COMMD1, GLRX, DCTN4, and ZBTB16, were analyzed in the 12 patients with Wilson disease. Results: Three nonsynonymous variants including c.1084A>G (p.Thr362Ala) in the exon 12 of the DCTN4 gene were identified in the patients examined. Among these, only p.Thr362Ala was predicted as possibly damaging protein function by in silico analysis. Examination of allele frequency of c.1084A>G (p.Thr362Ala) variant in the 176 patients with Wilson disease and in the 414 normal subjects revealed that the variant was more prevalent in the Wilson disease patients (odds ratio [OR]=3.14, 95% confidence interval=1.36-7.22, P=0.0094). Conclusion: Our result suggests that c.1084A>G (p.Thr362Ala) in the ATP7B-interacting DCTN4 gene may be associated with the pathogenesis of Wilson disease.

• Journal of Korean Academy of Nursing
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• v.26 no.3
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• pp.531-543
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• 1996

This study was done to develop a Maternal Identity Scale for Pregnant Women and to test the validity and reliability of the scale. A convenience sample of 161 pregnant women were asked to complete the MISP questionnaire which consisted of 45 item, this was done from December 20, 1995 to January 15, 1996. The research procedure were as follows. The first step was to identify a conceptual definition of maternal identity using Robin(1984)'s maternal identity and maternal experience during pregnancy. The second step was to operationalize the maternal identity, that is, perception of image possible of selves as mother, maternal role play by imagination, and the experiences of various emotional responses which are embedded in the mother-fetus dyad. The third step was item development which resulted in 45 items as appropriate measurement of maternal identity are except for the perception of image possible of selves as mother. The result findings were as follows : 1) Four factors for MISP (finally 40 items) were extracted through the principal component analysis and varimax rotation, and these contributed 49.3% of the variance in the total score. All 40 items in the scale loaded above .43 on one of 4 factors. 2) Each factor was named : factor 1 was named maternal role imagery and has 10 items, factor 2 was named happiness and has 11 items, factor 3 was named maternal fetal interaction and has 10 items, and the last factor 4 was named negative emotion and has 9 items. 3) Cronbach's -alpha coefficient for internal consistsncy was .92 for the total 40 items and .89, .90, .86, .78 for the four subscales in that order. Recommendations are suggested below : 1) The developed MISP be used to assess maternal readiness in pregnancy. 2) Replication study be done to test validity and relaibility. 3) For the overall measure of Maternal Identity in Pregnancy, scale for the perception of image possible of selves as mother, and cognitive domain be reorganized for the maternal identity in pregnancy. 4) It is necessary to identify variables that influences maternal pregnancy. 5) It Is necessary to identify that maternal identity in pregnancy is a reliable index of motherhood, to do correlation studies on maternal identity and major maternal variables in maternal transition period, to reoperationalize the maternal identity in postpartum, and finally to designate a longitudinal study of the maternal identity changes or stabilities.