• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.5 no.1
• /
• pp.59-67
• /
• 1995

Blood lead assay by $D_2$ lamp background correction method of atomic absorption spectrophotometer(AAS) with wavelength of 283.3 nm is most popular in occupational health practice in Korea. On the other hand, $D_2$ lamp background correction method with wavelength of 217.0 nm is also often used in general chemical analysis for lead assay in general purpose. But both methods have some weakness of background correction which brought direct effect on the results of analysis. Recently blood lead assay with polarized Zeeman effect of AAS was introduced and is now preferred in many laboratory than $D_2$ correction method in blood lead analysis. But still AAS with $D_2$ lamp are widely used in the field of occupational health in Korea. This study compared blood lead assay data with $D_2$ correction methods(283.3 and 217.0 nm) and with that of polarized Zeeman effect correction method to evaluate the validity of 02 correction methods. The results obtained were as follows; 1. Taking the value of polarized Zeeman effect method as reference value of 1.00, the mean relative value of $D_2$ correction method with wavelength of 217.0 nm was 0.92 and that with wavelength of 283.3 nm was 0.90 respectively in the analysis of blood lead whose value were below $20.0{\mu}g/dl$(p<0.001). Both mean values were statistically smaller than polarized Zeeman effect correction method. But in the analysis of blood whose value were between 20.0 to $20.0{\mu}g/dl$, the mean relative value of $D_2$ correction method was 0.96 in both wavelength and did not differ from polarized Zeeman effect method(p<0.001). There was no difference of blood lead between $D_2$ correction method and polarized Zeeman effect method in the analysis of blood lead whose value were over $40.0{\mu}g/dl$. 2. The variations of background correction value in polarized Zeeman effect method were not changed by increase of blood lead, but those in $D_2$ correction methods were increased by the increase of blood lead. While then relative standard deviation(RSD) of data measured by Zeeman effect method were decreased by the increase of blood lead, those by $D_2$ methods were nol differed by the increase of blood lead.

• Journal of Oral Medicine and Pain
• /
• v.31 no.1
• /
• pp.27-36
• /
• 2006

The cases of unidentified individual remains submitted to Forensic dentistry section in National Institute of Scientific Investigation, Korea were analyzed to study the application of forensic dental identification into individual identification in the period 2002-2005. The identification cases of unidentified remains were 405 out of 493, which accounted about 82% of whole cases. The incidence of submission of skeletons at least including the skull was increased from 58% in 2002 to 80% in 2005. The numbers of cases for the full examinations were 4 times more than that for age estimation in 2005. Twenty-four cases were submitted for skull to photographic superimposition and 15 out of 24 cases were examined, and the other 9 cases were examined by DNA analysis only. The submitted cases for dental comparison were 23 cases, 9 cases were positively identified, 4 cases were possible, 7 cases were excluded, and 3 cases ended up with insufficient evidences. The proportion of positive identification by dental methods was increased gradually from 9% in 2002 to 46% in 2005. Forensic dental identification has become important and useful because the availability of dental records and radiographs has been increasing. Compared to DNA analysis, forensic dental identification has several advantages such as no needs for high cost equipments and low expenses. And the interpretation of results is straightforward and speedy. These advantages are based on using primary their own dental records of the individuals rather than secondary DNA reference samples from family members. The application of the forensic dental identification to unidentified individual remains will be increased because the dental comparison can complement the limitation of DNA analysis and skull to photographic superimposition in many cases. In order to obtain positive identifications of unidentified remains, a close collaboration between the police and forensic scientists is important. The systemic approach including legislation to preserve dental records of unidentified remains and missing persons for the identification of unidentified remains should be needed.

• Korean Journal of Environment and Ecology
• /
• v.33 no.5
• /
• pp.506-514
• /
• 2019

Unlike natural ecosystems, the urban ecosystem proVides an interdependent enVironment in which wild organisms and urban people co-exist. Hornets (genus Vespa) appearing in urban green and parks haVe a positiVe effect on urban ecosystems, but they also cause ecosystem disserVices that cause physical and psychological discomforts to the urban people. Children's parks, for example, are Very popular among children and residents for easy accessibility, and hornets also use them as bases and habitats. HoweVer, there is still a lack of spatial analysis of habitats and appearance characteristics of hornets in children's parks. This study installed hornet traps in 27 children's parks in Cheonan from April to NoVember 2018 in consideration of the life cycle of hornets. We captured a total of fiVe Vespa species (Vespa crabro, V. analis, V. mandarinia, V. ducalis, and V. Velutina) for 32 weeks and analyzed the emergence of hornets in relation to the composition of seasonal characteristics, species characteristics, and enVironmental spatial information. We captured a total of 818 hornets during the study period. They included 290 V. analis (35.4%), 260 V. crabro (31.8%), 100 V. ducalis (12.1%), 87 V. mandaninia (10.6%), and 81 V. Velutina(9.9%). Most of the hornets showed a common feature that queen hornets were largely captured in May through June after they awake from hibernation, and the number of caught hornets decreased sharply beginning in mid-June, which was the cooperatiVe period. HoweVer, V. Velutina showed a seasonal specificity that more than 80% were captured beginning in the third week of October when other hornet species had already entered a decline phase. The analysis of the number of hornets caught in each spot in children's parks showed significant difference among the spots as 363 hornets (44.3%) were captured in top children's parks, and 35 hornets (4%) were captured in bottom children's parks. In particular, the mean NDVI (Normalized difference Vegetation index) of the top six children's parks was 0.79, and that of the bottom six children's parks was 0.38 (t=2.67*, *=p<0.05), indicating a significant difference. The frequency of capturing hornets was high when the ground around the children's parks was grass or bare land. This study is meaningful as a reference study that confirms the ecological characteristics of hornets appearing in green and parks in the city. We expect it to be a foundation for effectiVe urban green area management in the future.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.4
• /
• pp.395-404
• /
• 2021

Purpose. The purpose of present study was to evaluate the effect of changing structural stability of wax disc on the fit of prosthesis when the milling proceeded in order. Materials and methods. Prepared maxillary left first molar was used to fabricate a Ni-Cr alloy reference model. This was scanned to design crown and then wax pattern was milled, invested and cast to fabricate prosthesis. The wax patterns located in a row centrally within a single wax disc were set into a total of five groups ranging from WM1 group that was first milled to WM5 group that was last milled and the number of each group was set as 10. Silicone replica technique was used to measure the marginal gap, axial internal gap, line angle internal gap, occlusal internal gap. Data was evaluated with one-way ANOVA with significance level set at α = .05 and then Tukey HSD test was conducted for post analysis. Results. Marginal gap measured in each group, it was 40.41 ± 2.15 ㎛ in WM1 group, 40.44 ± 2.23 ㎛ in WM2 group, 39.96 ± 2.25 ㎛ in WM3 group, 39.96 ± 2.48 ㎛ in WM4 group, and 40.57 ± 2.53 ㎛ in WM5 group. No significant difference was found between groups. The significant difference between the groups was also not found in the axial internal gap, line angle internal gap, and occlusal internal gap. Conclusion. Internal and marginal fit of single crown to the sequential order of milling processing in the single machinable wax disc did not seem to be affected by the sequence.

• Korean Journal of Poultry Science
• /
• v.48 no.4
• /
• pp.287-295
• /
• 2021

In this study, we aimed to evaluate the impact of different feed withdrawal periods (2, 3, 4, 5, and 6 h) on Salmonella contamination in the crop, intestinal weight, and blood parameters of broilers before harvesting. A total of 100 broilers (initial live weight 1.906±0.06 kg) were randomly assigned to the same five treatment groups and broilers had access to water but no feed before catching. Feed withdrawal times were 2, 3, 4, 5, and 6 h prior to slaughter. Measurements included live weight, pre-slaughter weight, carcass weight, weight of gastrointestinal tract. In addition, Salmonella and Campylobacter contamination in the crop, serum biochemical profiles, counts of leukocytes, erythrocytes, and platelets, and meat quality were assessed. The results demonstrate that carcass weight, blood corticosterone, meat pH, meat color, and water holding capacity did not differ based on the feed withdrawal time. Carcass yield increased as the withdrawal time increased, but the weights of the crop, proventriculus, jejunum, ileum, and rectum were significantly reduced by 6 h (P<0.05). Salmonella counts were the lowest in the crops subjected to 6 h of feed withdrawal (P<0.05). Shear force was highest in chicken breast meat after 6 h of feed withdrawal (P<0.05). However, when the feed was withdrawn after 6 h, the shear force increased, but it did not affect the sensory characteristics in consumers, and the Salmonella count also decreased and had a reduction effect on contamination during slaughter. These findings can serve as reference data for setting the feed withdrawal time.

• Korean Journal of Heritage: History & Science
• /
• v.51 no.4
• /
• pp.44-65
• /
• 2018

This study examined the costumes of the characters in the painting titled Hig yongru Banghwoedo, which was designated as National Treasure No. 1879 in September 2015, and is currently kept in the Dongguk University Museum. The painting depicts a social gathering of Joseon aristocrats held at the higyongru, or watch tower, of the Gwangjumok, a government office, in 1567. It is characterized by the delicate illustration of the government officials, the main characters of the gathering, and the hyangri, ajeon, najang, chorye, akgong, and yeogi, the lower-class employees of the office. In order to investigate the costumes they wore, diverse materials including literature, costume artifacts, and paintings were used as reference sources. The scope of the study was limited to the characters' headdress and gown, and the accessories attached to the former. The study of men's clothing revealed that officials wore a samo and a red dalryeong as basic attire. In addition, it is presumed that they wore a belt indicating their official rank in the hierarchy, and a pair of black shoes. Retired officials wore a heuklip wrapped in horsehair or silk fabric with a red jing-nyeong and a doah. The hyangri wore a heukjukbanglip on their head, as well as a white jing-nyeong and a belted doah. In the Goryeo period, the banglip was a type of official headdress worn by members of the aristocratic elite ranked immediately below the king, but in Joseon it was demoted as the official headgear of the hyangri class, which was confirmed through Higyongru Banghwoedo. The ajeon wore a heuklip on their head, and a white jing-nyeong and a doah at the waist. As a rule, the najang wore a chogun on the head, and a banbieui on cheolrik and chungmokdai, but the najang in Higyongru Banghwoedo are depicted wearing a chogun and a cheolrik without a banbieui. Also, the chorye wore a heuklip wrapped in hemp cloth with a red cheolrik, whereas the akgong wore a somoja and a red cheolrik. Female entertainers, both adults and children, are depicted in the painting as either serving the aristocrats, dancing, or playing a musical instrument, wearing their hair in a voluminous, round, high bun, and dressed in a red daiyo, a hwangjangsam with a straight or reclined collar, and a belt. Notably, the donggi, i.e. young gisaeng, are shown wearing their hair in two short braids, and ddressed in a red gown with a y-shaped collar, or po.

• Journal of Intelligence and Information Systems
• /
• v.25 no.2
• /
• pp.99-122
• /
• 2019

According to the recent IDC (International Data Corporation) report, as from 2025, the total volume of data is estimated to reach ten times higher than that of 2016, corresponding to 163 zettabytes. then the main body of generating information is moving more toward corporations than consumers. So-called "the wave of Big-data" is arriving, and the following aftermath affects entire industries and firms, respectively and collectively. Therefore, effective management of vast amounts of data is more important than ever in terms of the firm. However, there have been no previous studies that measure the effects of big data investment, even though there are number of previous studies that quantitatively the effects of IT investment. Therefore, we quantitatively analyze the Big-data investment effects, which assists firm's investment decision making. This study applied the Event Study Methodology, which is based on the efficient market hypothesis as the theoretical basis, to measure the effect of the big data investment of firms on the response of market investors. In addition, five sub-variables were set to analyze this effect in more depth: the contents are firm size classification, industry classification (finance and ICT), investment completion classification, and vendor existence classification. To measure the impact of Big data investment announcements, Data from 91 announcements from 2010 to 2017 were used as data, and the effect of investment was more empirically observed by observing changes in corporate value immediately after the disclosure. This study collected data on Big Data Investment related to Naver 's' News' category, the largest portal site in Korea. In addition, when selecting the target companies, we extracted the disclosures of listed companies in the KOSPI and KOSDAQ market. During the collection process, the search keywords were searched through the keywords 'Big data construction', 'Big data introduction', 'Big data investment', 'Big data order', and 'Big data development'. The results of the empirically proved analysis are as follows. First, we found that the market value of 91 publicly listed firms, who announced Big-data investment, increased by 0.92%. In particular, we can see that the market value of finance firms, non-ICT firms, small-cap firms are significantly increased. This result can be interpreted as the market investors perceive positively the big data investment of the enterprise, allowing market investors to better understand the company's big data investment. Second, statistical demonstration that the market value of financial firms and non - ICT firms increases after Big data investment announcement is proved statistically. Third, this study measured the effect of big data investment by dividing by company size and classified it into the top 30% and the bottom 30% of company size standard (market capitalization) without measuring the median value. To maximize the difference. The analysis showed that the investment effect of small sample companies was greater, and the difference between the two groups was also clear. Fourth, one of the most significant features of this study is that the Big Data Investment announcements are classified and structured according to vendor status. We have shown that the investment effect of a group with vendor involvement (with or without a vendor) is very large, indicating that market investors are very positive about the involvement of big data specialist vendors. Lastly but not least, it is also interesting that market investors are evaluating investment more positively at the time of the Big data Investment announcement, which is scheduled to be built rather than completed. Applying this to the industry, it would be effective for a company to make a disclosure when it decided to invest in big data in terms of increasing the market value. Our study has an academic implication, as prior research looked for the impact of Big-data investment has been nonexistent. This study also has a practical implication in that it can be a practical reference material for business decision makers considering big data investment.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.13 no.6
• /
• pp.155-166
• /
• 2018

The purpose of this study is to analyze the impact of self-efficacy of SMEs' organization members on job engagement and job performance, and to analyze the difference between gender and marital status by applying SEM-ANN analysis. To accomplish the study purpose, 285 valid samples were collected from 400 SMEs' organization members and analyzed. In this study, self - efficacy consisted of three sub-dimensions: self-confidence, self-regulation efficacy, and task difficulty preference. As a result of the analysis, self - efficacy such as self-confidence, self-regulation efficacy, and task difficulty preference had a positive direct effect on job engagement. In addition, self-efficacy and self-control efficacy have a positive effect on job performance, but the preference of task difficulty has no significant effect. In addition, job engagement has a positive(+) effect on job performance, and has a mediating role in the relationship between self-efficacy and job performance. Also, married males preferred self-regulation efficacy, while females preferred self-regulation and self-control efficacy regardless of marital status. The purpose of this study is to present the framework of self-efficacy-job engagement-job performance of SMEs by measuring the self-efficacy related researches mainly in education and service industries, and is meaningful that companies can help to find the basis of management of organization members by gender and marital status of organization members. In addition, the SEM-ANN analysis process of this study is different in that it explains the nonlinear (nonobservative) relationship that can analyze the influence or the combination of the reference variables in the linear (compensatory) relation using the SEM.

• Korean Journal of Heritage: History & Science
• /
• v.42 no.4
• /
• pp.152-171
• /
• 2009

The Dancheong(丹靑) of the main building of Mihwangsa Buddhist Temple(美黃寺) in Haenam(海南) is the leading work of the Jeolla Dancheong style, which was created in the 18th century and has been passed down to the early modern days, and boasts its excellence and originality. On the outside, one can only see the traces of the Dancheong due to the colors that fell off and deteriorated severely. On the inside, however, the general Dancheong pattern is accompanied by the painting of 1,000 Buddhas(千佛圖), which is hardly found in other Buddhist temples, and the Arahan painting, which is truly magnificent in technique and can pass as an independent painting. The Dancheong also has unique methodological characteristics that can't be found in other Dancheong works such as the painting and attaching technique. The Dancheong inside is estimated to have been created in 1754 considering the records of "Dalmasan Mihwangsasa Daebeopdang Jungsusangryangmun(達摩山美黃寺大法堂重修上樑文)", the calligraphical writings of "Mudeungsanindanhwakya(無等山人丹?也)"and "Geonryungshipgu(乾隆十九)" left in the Jungryang, and the style characteristics reflected in the Dancheong patterns and the painting of 1,000 Buddhas. The fact that there are no traces of re-Dancheong also supports the estimation that the Dancheong was created in the absolute age of 1754. The absolute age will be the reference of deciding the chronological years of Dancheong patterns and be helpful in examining the characteristics and changes by the periods. There were certain style characteristics in Dancheong by the periods and regions. The Dancheong of Jeolla region also had its own style, which includes the tendency of finishing with two- or three-fold green belts without giving meokdanggi to the meoricho and the huge jar decoration of huigol. Treating the baetbadak of all materials, whether it's Geumdancheong or morodancheong, with lines of certain thickness and colors is another style of Jeolla Dancheong from the 18th to the 20th century. The Dancheong of the Geukrakbojeon(極樂寶殿) of Cheoneunsa Buddhist Temple and Daewoongbojeon(大雄寶殿) of Naesosa Buddhist Temple in Jeolla is especially noteworthy in that it bears similar patterns and techniques to that of the main building of Mihwangsa Buddhist Temple in addition to the characteristics mentioned above. The Dancheong of Mihwangsa Buddhist Temple must have exerted so great influences on that of the two temples that it's called "the style of Mihwangsa Buddhist Temple."When adopting a broader point of view, it can be classified as one of the Dancheong styles of Jeolla. The common icons and techniques found in the Dancheong of Mihwangsa, Cheoneunsa, and Naesosa Buddhist Temple provide some clues about the influential relationships among painters of the days. They may have been created by the painters of the same school or the painters affected by those who created the Dancheong of Mihwangsa Buddhist Temple.

• Korean Journal of Environment and Ecology
• /
• v.33 no.4
• /
• pp.440-446
• /
• 2019

This study examined the growth and fruiting characteristics and the acorns biomass allometric equation of Quercus acuta to provide reference data related to the growth and seed supply during the restoration of evergreen forest in the warm temperate zone in Wando Island, Korea. For the growth survey, we selected and cut three sample trees having a mean diameter at breast height (DBH) to investigate the growth analysis through a stem analysis. We then developed the allometric equation (Y=aX+b) of DBH and tree height growth characteristic (Y) according to the average tree age (X) of sampled trees and estimated the DBH and tree height according to the age of Quercus acuta. For the fruiting survey, we selected and cut three sample trees with full fruit in August when, they are at the early mature fruiting stage, for the analysis. To develop the acorns/tree biomass allometric equation of Quercus acuta, we selected and cut ten sample trees of evenly divided diameters. The acorns biomass allometric equation ($Y=aX^b$) was derived by analyzing the biomass (Y) and the growth characteristics (X), such as the DBH, tree height, crown width, and crown height. The allometric equations of average tree age according to DBH and tree height were Y=0506X-2.064 ($R^2=0.999$) and Y=0.321X+0689 ($R^2=0.992$), respectively. The developed allometric equations estimated that the DBH were 3.0cm, 8.1cm, 13.1cm and 18.2cm while the tree heights were 3.9m, 7.1m, 10.3m, and 13.5m when the tree ages were 10, 20, 30, and 40 years, respectively. The analysis results of fruiting characteristics showed that the length, the diameter, the number of fruits, and the number of acorns per fruiting branch had the statistically significant difference and tended to decrease from the upper part to the lower part of crown downward. The total number of acorns was 1,312 acorns/tree in the upper part, 115 acorns/tree in the middle part, and 5 acorns/tree in the lower part of the crown. The allometric equation for the amount of acorns with DBH as an independent variable was $Y=0.003X^{4.260}$ with the coefficient of determination at 0.896. Although the coefficient of determination of the allometric equation using only DBH as the independent variable was lower than that using DBH and tree height ($D^2H$), it would be more practical to consider only DBH as the independent variable because of measurement errors.