• Economic and Environmental Geology
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• v.26 no.2
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• pp.175-185
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• 1993

Soils and dusts collected from Changhang smelter area were analyzed for Cu, Pb, Zn, and Cd in order to determine their dispersion pattern and mode of occurrences, and to investigate the pollution level of heavy metals such as Cu, Pb, Zn, and Cd by smelting activity. The soil pH of Changhang area is in the range of 3.7~8.8, and increased with increasing distance from the smelter site. The particles containing heavy metals are several tens of ${\mu}m$ in diameter, and have well crystal form. Samples collected near the smelter show similar particle properties in size, shape, and composition, which means that they could be originated from the same contamination source. Element couples of Cu, Pb, Zn, and Cd indicate high correlation with each other, which means that Cu, Pb, Zn, and Cd could be originated from the same point source of smelter. Heavy metal contents were decayed to background levels from 2.5 kilometer away from the smelter.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.2
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• pp.159-173
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• 1999

Based on air quality monitoring data('89~'97) operated by the Department of Environment, we provide various fundamental statistics for ground ozone. The purpose of this paper are to review the national ambient ozone standard, to study spatial distribution of ozone. Since we, in Korea, calculate average ozone level, to examine the occurrences of ozone level 3 times a day (1~8, 9~16, 17~24 hours), the method does not seem to be scientifically sound comparing to a running average method adapted by the USEPA. When we counted the number of cases with 8-h average O3 level exceeding 60ppb(8-h average standard in Korea)and 80 ppb (that in the U.S.A) and also when we calculated 8-hour average ozone level based on th US method, some regions were classified as non-attainment areas. Especially in Seoul, results of spatial distribution analysis showed that high level ozone over 80 ppb was observed at Kuui-Dong and Pangi-Dong in the eastern part and at Ssangmun-Dong in the northeastern part. Also, occurrences of ozone episode defined as number of days then ozone level exceeding 80 ppb for 3 consecutive hours were extensively reviewed in this paper.

• Geomechanics and Engineering
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• v.1 no.2
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• pp.143-154
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• 2009

Many factors influence occurrences of rock burst in coal mines, such as mining methods, control methods of the coal roof, lithological characteristics of the roof and floor, tectonic stress, groundwater and so on. Among those factors, lithological characteristics in the roof are the intrinsic controlling factors that affect rock burst during coal mining. Tangshan colliery is one of the coal mines that have suffered seriously from rock bursts in China. In this paper, based on the investigating the lithological characteristics of coal roofs and occurrence of rock bursts in Tangshan colliery, a numerical method is used to study the influence of roof lithological characteristics on rock burst potential. The results show that the lithological characteristics in the roof have an important impact on the distributions of stresses and elastic strain energy in coal seams and their surrounding rocks. Occurrences of rock bursts in this colliery have a close correlation with the thick-bedded, medium- to fine-grained sandstones in the roof. Such strata can easily cause severe stress concentration and accumulate enough energy to trigger rock bursts in the working face during mining operations.

• MALSORI
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• no.21_24
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• pp.3-24
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• 1992

This study was designed to investigate the changes of phonological processes in normal Korean children aged from 2- to 6-years. Forty eight children who lived in Seoul or Kyung-Ki do were tested with a picture articulation test and their articulation errors including omissions, additions and substitutions were coded into phonological processes. Those phonological processes were discussed in several ways: syllable structure, place, manner, assimilation, tenseness, and aspiration of sounds. Data were analyzed by two ways: (1) number of subjects who showed each process and (2) percentage of occurrence of each process. Analyses in omission-addition processes demonstrated that postvocalic omission occurred most frequently, followed by velar-, alveolar-, and glottal omission. Analyses in substitution processes showed that fronting (palatal and velar), backing (alveolar), and alveolization occurred most frequently in terms of the place of sounds. In terms of assimilation, alveolar-, stopping, and aspiration assimilation occurred frequently. Analyses by the tenseness and aspiration showed similar occurrences among the 4 processes, with slightly higher occurrences in tensing and aspiration than lanxing and deaspiration. All of the processes decreased by age. The numbers of the processes showed by more than half of the children or exceeded 10％ of occurrence were 20 in 2-years of age, 10 in 3-years of age, 1 in 4-years of age, and none in ages of 5 and 6.

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.441-448
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• 2011

According to the Korean government policy of expanding HACCP system application to food chain from farm to meat market, the importance of HACCP assessment to keep balance among the certified HACCP plants is urged. The objective of this study is to recommend more effective HACCP assessment methods. We reviewed major foreign countries HACCP implementation policy focused on the audit system, and compared with the Korean HACCP assessment system. We found that the checklist guidelines of prerequisite program were not enough for precise evaluation and many of the items were not directly related to the risk occurrences. And current rating grade for each items and judgments were inadequate to induce non-compliances and corrections for better HACCP implementation. We suggest revision points as follows; (1) checklists should be revised and reorganized according to the possibility of risk occurrences, (2) all the items should be supported by detailed guidelines for more objective inspection, (3) non-compliances identified must be reconfirmed after correction, (4) the items for HACCP plan should be divided into an accreditation inspection and a regular inspection, (5) rating grade 'high', 'medium', 'low', 'failure' was better for indicating non-compliances.

• Journal of the Korea Safety Management & Science
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• v.16 no.2
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• pp.53-61
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• 2014

The disaster and safety accidents in any construction site occur inevitably. Since the on-site disaster and accident occurrence became one of major concerning factors in construction site, architects & building executers have been flooded with safety management advices. The purpose of this paper is to survey and analyze the effect of the application of Safety Patrol Management System(SPMS) upon the reduction of disaster & accident occurrences in construction site. In order to estimate and reduce the disaster and accident ratio in construction site, various surveyed data has been analysed. It will establish the suitable design standards and suggest the basic database for estimating disaster and accident ratio.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.6_spc
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• pp.697-704
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• 2016

The second shutdown drive mechanism (SSDM) that is classified into seismic category I as an active mechanical equipment shall maintain the structural integrity and its designed inherent safety functions during and/or after normal operation, anticipated operational occurrences, accidents and seismic occurrences. Therefore, not only a structural integrity assessment through numerical analyses but also a qualification test by using the prototype SSDM shall be conducted to verify the adequacy of the SSDM design. This paper describes a sort of seismic qualification test of the prototype SSDM to demonstrate that the structural integrity and operability (functionality) of SSDM are maintained during and/or after seismic excitations. From the results, this paper shows that the SSDM satisfies all design requirements without any malfunctions during and after the seismic test.

• Journal of Power Electronics
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• v.19 no.6
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• pp.1566-1574
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• 2019

Maximum power point tracking (MPPT) under the partial shading condition is a challenging research topic for photovoltaic systems. Shaded photo-voltaic module result in complex peak patterns on the power versus voltage curve which can misguide classical MPPT algorithms. Thus, various kinds of global MPPT algorithms have been studied. These have typically consisted of partial shading detection, global peak search and MPPT. The conventional partial shading detection algorithm aims to detect all of the occurrences of partial shading. This results in excessive execution of global peak searches and discontinuous operation of the MPPT. This in turn, reduces the achievable power for the PV module. Based on a theoretical investigation of power verse voltage curve patterns under various partial shading conditions, it is realized that not all the occurrences of partial shadings require a global peak search. Thus, an intelligent partial shading detection algorithm that provides exact identification of global peak search necessity is essential for the efficient utilization of solar energy resources. This paper presents a new partial shading determinant algorithm utilizing adaptive threshold levels. Conventional methods tend to be too sensitive to sharp shading patterns but insensitive to smooth patterns. However, the proposed algorithm always shows superb performance, regardless of the partial shading patterns.

• Journal of Mycology and Infection
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• v.23 no.4
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• pp.105-110
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• 2018

Background: Otomycosis is a fungal infection that comprises 7~10% of outer ear infections. Although the occurrence is higher in humid climates, relatively few studies have investigated otomycosis occurrences in humid environments. While recurrent chronic otitis media discharge in the ear creates a milieu in which otomycosis is likely to occur, investigations of otomycosis co-occurring with chronic otitis media have been rare. Objective: To examine the characteristics of patients with otomycosis co-occurring with chronic otitis media and identify causative fungi. Methods: The study included 60 patients with chronic otitis media who presented typical otomycosis findings in the outer ear canal and the presence of fungi. Patients were treated in the department of otolaryngology, Daegu Catholic University Medical Center, between July 2011 and June 2018. Results: The mean patient age was 57.77 years, and our study included 20 men and 40 women (p=0.010). The lesion was on the right in 39 patients and on the left in 21 (p=0.020). Ear discharge was the most common chief complaint at diagnosis. Of the 54 patients over age 19, 10 had diabetes (18.5%). Aspergillus was causative in 29 patients and Candida in 31. Aspergillus niger was identified in 15 patients, Aspergillus sp. in 14, Candida parapsilosis in 12, Candida sp. in six, and Candida albicans in five. Conclusion: Otomycosis and chronic otitis media co-occurrences increase with age. The Aspergillus and Candida genera were similar in proportion. A. niger was the most common Aspergillus species, while C. parapsilosis was the most common Candida.

• Research in Plant Disease
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• v.27 no.4
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• pp.155-163
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• 2021

Dried red peppers are frequently contaminated with mycotoxins during storage. To determine the effect of storage environments on fungal occurrence and subsequent mycotoxin accumulation in dried red peppers, we monitored red pepper powder and whole fruit samples for fungal occurrence under various temperatures and relative humidity (RH) conditions during 340 days. Fungal occurrences fluctuated in both pepper forms throughout the storage but they were higher in pepper powder than whole one, higher under low temperatures (-20℃, 0℃, or 4℃) than others (10℃, 25℃, or 30℃), and higher under RH 93% than RH 51% and 69% in both peppers. The samples exhibiting high fungal occurrences were associated mainly with dominant species such as Aspergillussydowii, Penicillium solitum, P. roqueforti, P. polonicum, or P. chrysogenum. Mycotoxigenic species, including A. flavus, A. ochraceus, A. westerdijkiae, A. tubingensis, and P. citrinum, were also detected throughout the samples. Although mycotoxins were not detected in the samples, mycotoxigenic potential of A. flavus, A. ochraceus, and A. westerdijkiae isolates were confirmed. These results show that low temperatures (-20℃, 0℃, or 4℃) and/or high surrounding RH (>93%) are not safe environments for storage of dried red peppers as fungal growth can occur under these conditions.