• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.04a
• /
• pp.808-813
• /
• 2011

There are hundreds of thousands call center workers wearing acoustic device. However, researches and noise exposure measurements on the noise transmitted from acoustic devices have seldom been performed due to the difficulty of measurement and to the absence of the measuring method in Korea. The aim of this study is to set up management measures to protect hearing loss on the call operator by acquiring measurement data of noise transmitted from the headset Noise exposure measurements of 17 operators were performed in 7 call centers and Head and Torso Simulator method in compliance with the ISO Standard 11904-2 was used for the measurement of noise transmitted from the headset Sound pressure levels(SPL) transmitted from the headset were 73.2~86 dB(A). The operator exposed to the highest SPL set up his volume control at 9 which was the highest volume level. The volume control level, adjustable from 1 to 9, could be identified 12 out of 17 operators and the range of volume levels was 4.5~9. As a result of Pearson Correlation Analysis, the correlation between volume level and SPL transmitted from the headset showed high relation as significance at the 0.672 level(p<0.05). To protect hearing loss of call center operators, it is more practical and effective measure to limit the volume level below the noise exposure level, i.e. 85 dB(A), rather than to carry out noise monitoring considering cost-effective aspect.

• Korean journal of food and cookery science
• /
• v.30 no.3
• /
• pp.307-316
• /
• 2014

This study was carried out in order to investigate the quality characteristics of baguette with different amounts of yeast and fermented rice bran sourdough(Control: Yeast 30 g + Fermented rice bran sourdough 0 g, A sample: Yeast 20 g + Fermented rice bran sourdough 150 g, B sample: Yeast 10 g + Fermented rice bran sourdough 300 g, C sample: Yeast 0 g + Fermented rice bran sourdough 450 g). The pH of fermented rice bran sourdough by fermentation time was decreased as the fermentation time was longer. The pH of baguette dough was decreased as the fermented rice bran sourdough increased; the volume was the highest in control at the 1st fermentation, and in the B sample at the 2nd fermentation. The weight of baguette was the highest in the C sample, and the volume and specific volume were the highest in the B sample. The microstructure of the cross section analysis indicated that the air cell of baguette crumb was large and regular in the B sample. The moisture content and water binding capacity were the highest in the B sample, although significantly different. The L value was decreased as there was an increasing addition ratio of fermented rice bran sourdough; further, the a and b values were decreased with an increase in baguette volume. Hardness, gumminess and chewiness were decreased as volume and specific volume were increased; yet, springiness was increased. According to the result of the sensory evaluation, the flavor, taste, appearance and texture were the highest in the B sample.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.21 no.7
• /
• pp.615-621
• /
• 2011

There are hundreds of thousands call center workers wearing acoustic device. However, researches and noise exposure measurements on the noise transmitted from acoustic devices have seldom been performed due to the difficulty of measurement and to the absence of the measuring method in Korea. The aim of this study is to set up management measures to protect hearing loss on the call operator by acquiring measurement data of noise transmitted from the headset. Noise exposure measurements of 17 operators were performed in 7 call centers and head and Torso simulator method in compliance with the ISO standard 11904-2 was used for the measurement of noise transmitted from the headset. Sound pressure levels(SPL) transmitted from the headset were 73.2~86 dB(A). The operator exposed to the highest SPL set up his volume control at 9 which was the highest volume level. The volume control level, adjustable from 1 to 9, could be identified 12 out of 17 operators and the range of volume levels was 4.5~9. As a result of pearson correlation analysis, the correlation between volume level and SPL transmitted from the headset showed high relation as significance at the 0.672 level(p<0.05). To protect hearing loss of call center operators, it is more practical and effective measure to limit the volume level below the noise exposure level, i.e. 85 dB(A), rather than to carry out noise monitoring considering cost-effective aspect.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.51 no.3
• /
• pp.454-460
• /
• 2015

The present study is undertaken to evaluate the effect of volume fraction on the results of Charpy impact test for the rubber matrix filled with nano sized silica particles composites. The Charpy impact tests are conducted in the temperature range $0^{\circ}C$ and $-10^{\circ}C$. The range of volume fraction of silica particles tested are between 11% to 25%. The critical energy release rate $G_{IC}$ of the rubber matrix composites filled with nano sized silica particles is affected by silica volume fraction and it is shown that the value of $G_{IC}$ decreases as volume fraction increases. In regions close to the initial crack tip, fracture processes such as matrix deformation, silica particle debonding and delamination, and/or pull out between particles and matrix which is ascertained by SEM photographs of Charpy impact fracture surfaces.

• Korean System Dynamics Review
• /
• v.15 no.3
• /
• pp.5-36
• /
• 2014

The purpose of this paper is to develop a System Dynamics model for estimating the volume of forest resources in the future and simulating the volume of function of public benefit linked to forest resources in dynamic manner. Also it is to analyze the impact when the volume of forest land conversion is controlled by policy using the SD model. The analysis was done at nation-wide for the simulation period 2000 to 2040. Estimated forest area was 6.2 million ha and estimated growing stock was $4.7\;billion\;m^3$ in 2040 from the future forecast without policies. Changing of forest resources, 13.9 billion tons of forest-ground-water storage was estimated, $1.8\;million\;m^3$ of erosion control of forest was estimated and 377 million tons of $CO_2$ absorption was estimated. As a result of simulation with two alternatives, forest area was less reduced and growing stock was bigger than do nothing policy. Also, function of public benefit reflected by changes of forest resources was enhanced. This study contributes to estimate the quantitatively measured volume of forest resources and function of public benefit over the 30 years in Korean forest land in scientific way. Using this SD model, decision maker would develop forest land policies more delicately for deserving forest resources and increasing the volume of function of public.

• Culinary science and hospitality research
• /
• v.22 no.7
• /
• pp.173-186
• /
• 2016

This study was conducted to investigate quality characteristics of white pan bread with Cudrania tricuspidata leaf powder having functional components. Mixograph, pH, TPA, volume, specific volume, moisture, CrumbScan, color value, sensory evaluation and shelf-life test were performed on the white pan bread with Cudrania tricuspidata leaf powder. The obtained results are as follows. Mixogram analysis results showed that the dough with Cudrania tricuspidata leaf powder was suitable for baking quality. The more Cudrania tricuspidata leaf powder was added in the dough, the higher dough pH was and the lower pH values after fermentation and of the final productwere. TPA analysis results showed that higher amounts of Cudrania tricuspidata leaf powder resulted in increased hardness, chewiness, and gumminess of the white pan bread. Volume and specific volume of white pan bread were decreased with increased amounts of Cudrania tricuspidata leaf powder. CrumbScan images showed that fineness of grain, crust thickness, and volume of the bread were significantly different depending on the amount of Cudrania tricuspidata leaf powder. While color value analysis showed that increasing the amount of Cudrania tricuspidata leaf powder resulted in low L and a values. The results of the acceptance test showed that CLP3 had better scores in the appearance and texture characteristics than the control, while taste and overall acceptance were higher in the CLP2 compared with the control. According to the results of the shelf-life test, the white pan bread with 1~2% of Cudrania tricuspidata leaf powder had a significantly lower hardness when compared with the control. It was judged that a lower amount of Cudrania tricuspidata leaf powder could help in maintaining the softness of bread crumbs. Moisture content in the white pan bread decreased with the increased amounts of Cudrania tricuspidata leaf powder, but there were no significant differences among specimens.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.17 no.2
• /
• pp.115-126
• /
• 2006

Background and Objectives : Training of breath support and laryngeal muscles control are important components in the development of the singing voice. The purpose of this study is to compare characteristics of respiratory and phonatory control on pitch, loudness, register change with untrained males and trained male singers. Materials and Methods : The 11 untrained males and 11 trained male singers participated. Closed Quotient(CQ), fundamental frequency (fo) and relative volume contribution of the rib cage (in percentage rib cage, % RC) and relative volume contribution of abdomen (in percentage abdomen, % AB) were measured during various pitch, loudness, register tasks using /a/ vowel phonation : Legato, staccato with C3-D3-E3-F3-G3 notes and crescendo and decrescendo with C3 note as well as modal register with C3 and falsetto register with C4 note using an integrated analysis system of Respiration, EGG and Voice. Results : (1) When pitch increased with legato task, loudness also increased in untrained male group but maintained in trained male singers. CQ was also increased both untrained and trained male singers but it was not significantly different ($p>.05$). The abdomen contribution to lung volume were significantly predominant both in inhalation and exhalation in trained males singers ($p<.05$). (2) When pitch increased with staccato task, CQ was not significantly different in untrained but significantly different in trained male singers. The respiratory function of male singers were characterized by significantly predominant abdomen contribution to lung volume in exhalation except for inhalation ($p<.05$) (3) When loudness increased with crescendo, fo was significantly increased with increasing CQ in untrained males but fo was relatively consistent with increasing CQ in trained male singers. The respiratory function of male singers were characterized by significantly predominant abdomen contribution to lung volume in exhalation except for inhalation ($p<.05$). (4) Most male singers were able to change register from modal to falsetto register, but untrained males were not. Thus, CQ was significantly different between modal and falsetto register in trained male singers ($p<.05$). The respiratory function of male singers were characterized by significantly predominant abdomen contribution to lung volume in exhalation except for inhalation ($p<.05$). Conclusion : Male singers were superior to untrained males in coordination of respiratory and phonatory control on pitch, loudness, register change. Implication are offered regarding how the results might be applied to the voice therapy as well as singing training.

• Knowledge Management Research
• /
• v.11 no.1
• /
• pp.83-96
• /
• 2010

In this study, the effect of firm's patent competency on the their management performance was analysed. The number of patents granted to Korean firms, patent grade score as of the firm's patent competence were considered in the perspectives of patent volume and patent value respectively. Specially the analysis were implemented focusing on the high performance venture ranked 200th in Korea. The patent source data were from the Korean Intellectual Property Office, Korean Credit Evaluation Information Company, and the Patent Evaluation System of KIPO and KIPA. And the year sales and net profit volume as of the firm's management performance data from the KIS. Management performance data are consisted of the mean sales, net profit and ROI during the 4 years from FY2005 to FY2008. Major results are as follows. The regression model were proved significantly that the year sales volume and net profit are effected by the number of patents and patent grade score. But the model including the ROI were shown not significantly. So it can be concluded that patent volume and patent value are the important factors on firm's financial performance as of the year sales volume and net profit. Also the regression model including the control variables, firm's number of employee and business year, the number of patents and patent grade score are the significant factors on firms performance. And regression coefficients of patent value model were higher than these of patent volume model. So it can be recognized that patent value of firms' patent competency are more important factor than the patent volume.

• BLOOD RESEARCH
• /
• v.53 no.4
• /
• pp.269-275
• /
• 2018

Coronary artery ectasia (CAE) is defined as the dilation of a segment of a coronary vessel to at least 1.5 times the diameter of its normal adjacent segment. Mean platelet volume (MPV) plays a role in acute coronary syndromes, with high MPV correlating to poor prognosis for acute thrombotic events and CAE. Several studies investigated the relationship between MPV and CAE, resulting in conflicting results. These results led us to systematically review all studies investigating the relationship between MPV and ectatic heart diseases by performing a meta-analysis study in order to report a unified result. This meta-analysis study investigated all case-control articles examining the relationship between MPV and CAE. All studies in the following databases published until January 31, 2018, were investigated: Science Direct, Scopus, PubMed, Google Scholar, and Web of Science. Following a quality control evaluation, 14 articles, all of which were published following studies performed in Turkey from 2007 to 2016, met the criteria for study inclusion. After pooling the results from all of the articles, a total standardized mean difference (SMD) value of 0.584 (95% CI, 0.219, 0.95) was obtained using the D+L pooled SMD, indicating a significant difference (P=0.002) between the two groups, with higher MPV values in ectatic patients when comparing to healthy individuals. Therefore, increased MPV levels were significantly related to CAE, suggesting that platelets, with their inflammatory and thrombotic activities, play a role in this disease. Therefore, anti-platelet and anti-inflammatory therapies may be effective in treating CAE.

• International Journal of Automotive Technology
• /
• v.8 no.5
• /
• pp.563-573
• /
• 2007

Optimal design of an automotive catalytic converter for minimization of cold-start emissions is numerically performed using a micro genetic algorithm for two optimization problems: optimal geometry design of the monolith for various operating conditions and optimal axial catalyst distribution. The optimal design process considered in this study consists of three modules: analysis, optimization, and control. The analysis module is used to evaluate the objective functions with a one-dimensional single channel model and the Romberg integration method. It obtains new design variables from the control module, produces the CO cumulative emissions and the integral value of a catalyst distribution function over the monolith volume, and provides objective function values to the control module. The optimal design variables for minimizing the objective functions are determined by the optimization module using a micro genetic algorithm. The control module manages the optimal design process that mainly takes place in both the analysis and optimization modules.