• 대한인간공학회지
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• 제26권2호
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• pp.45-59
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• 2007

The operating tasks of overhead crane have caused undue stress to the operators from physical, mental, and environmental workload. Existing workload assessment models for musculoskeletal disorders such as OWAS, RULA, and QEC have limited applicability to the crane operating tasks because they focus mainly on physical factors and do not consider the relative importance of each factor. The present study was to develop a workload assessment model customized to overhead crane operation, following a systematic process: (1) analyzing task characteristics, (2) selecting workload factors, (3) developing assessment methods, (4) establishing action levels, and (5) computerizing the assessment model. Based on literature review, worksite survey, and focus group interview, 4 physical factors (awkward posture, static posture, repetitive motion, and excessive force), 6 mental factors (visual demand, auditory demand, task complexity and difficulty, time urgency, work schedule related stress, and safety related stress), and 4 environmental factors (noise, vibration, dust, and temperature) were selected and their rating scales and relative weights were determined. Then, based on the workload assessment results of 8 overhead cranes operated at different workplaces, the action levels of each factor category were established. Finally, the crane operation assessment model was computerized for effective analysis and report preparation. The present approach is applicable to develop a customized workload assessment model for an operating task under consideration.

• 약학회지
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• 제32권5호
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• pp.295-303
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• 1988

For microbial production of acetaminophen, a popular analgesic-antipyretic from aniline, we screened various fungi and bacteria. And we succeeded to some extents in acetaminophen production by successful protoplast fusion between S. lividans and S. globisporus and also between S. rimosus and S. aureofaciens. However, more fertile results might be brought via performing the cloning of acetanilide p-hydroxylation genes of Streptomyces in yeast. This study was initiated to determine whether the acetanilide p-hydroxylase of Streptomyces is cytochrome P-450 species or non-heme iron protein species. The p-hydroxylationactivity on acetanilide in S. aureofaciens ATCC 10762 was found to be unstable on exposing to the air. However, 100,000xg supernatant of the cell free extracts which were prepared in $N_2$ atmosphere showed the p-hydroxylation activity. Characteristic absorption peak of cytochrome P-450 after reduction with dithionite and addition of CO was not observed in the region of 450nm. Moreover, metyrapone and 2, 6-dichloroindophenol did not affect this enzyme activity, but sodium azide, sodium cyanide, cupric sulfate, cadmium chloride, ${\alpha}$, ${\alpha}'-dipyridyl$, and o-phenanthroline reduced p-hydroxylase activity considerably. S. fradiae NRRL 2702 was shown to have strong p-hydroxylation activity in intact cells. This activity disappeared in its cell free extracts. In its 100,000xg supernatant, however, characteristic absorption peak of cytochrome P-450 after reduction with dithionite and addition of CO was observed at 446nm. Thus, the results herein presented suggest that acetanilide p-hydroxylase of Streptomyces aureofaciens is not related to cytochrome P-450 and may include non-heme iron protein for its activity. However, it is not clear whether acetanilide p-hydroxylase in S. fradiae belongs to the same category of S. aureofaciens.

• 대한가정학회지
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• 제48권1호
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• pp.67-81
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• 2010

Consumer researchers found that compulsive buying was a part of a category of compulsive consumption that was interrelated to addictive and repetitive behaviors. The present study empirically examined the co-morbidity of compulsive buying and Internet addiction among e-commerce users in terms of consumption disorders. Although the prevalence of Internet use and on-line sales remarkably increase in recent years, almost no study examines on-line compulsive buying behavior. This study explored the link between compulsive buying and Internet addiction among e-commerce users, and investigated the characteristics of on-line shoppers with respect to two forms of compulsive consumption, which were divided into compulsive buying and Internet addiction. Additionally, factors that related to compulsive buying behaviors among e-commerce users were also examined. The present research was conducted using a convenience sample of 394 young adults between the ages of 20-30, and the Faber and O'Guinn's DSCB scale and the Widyanto's Internet addiction scale (IA) were used. Confirmatory factor analyses were utilized to evaluate the structure of the DSCB and IA, and a Probit model was used to examine determinants for the compulsive buying behaviors of e-commerce users. E-commerce users were classified into four groups; high compulsion and high addiction, low compulsion and low addiction, high compulsion and low addiction, and low compulsion and high addiction. Consumers with high compulsion and high addiction spent higher amounts of money on their on-line purchases and were frequently connected with the Internet compared to the three other consumer groups. Consumers with compulsive buying behaviors were also found to have significantly greater Internet addiction tendencies than typical buyers. Compulsive buyers were more likely to engage in Internet addiction and the number of purchasing via on-line shopping mall, and had higher materialism. Policy implications and suggestions for consumer education programs were discussed.

• Restorative Dentistry and Endodontics
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• 제42권2호
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• pp.105-110
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• 2017

Objectives: This study investigated the cleaning ability of ultrasonically activated irrigation (UAI) and a novel activation system with reciprocating motion (EC, EasyClean, Easy Equipamentos $Odontol\acute{o}gicos$) when used with a relatively new chelating agent (QMix, Dentsply). In addition, the effect of QMix solution when used for a shorter (1 minute) and a longer application time (3 minutes) was investigated. Materials and Methods: Fifty permanent human teeth were prepared with K3 rotary system and 6% sodium hypochlorite. Samples were randomly assigned to five groups (n = 10) according to the final irrigation protocol: G1, negative control (distilled water); G2, positive control (QMix 1 minute); G3, QMix 1 minute/UAI; G4, QMix 1 minute/EC; G5, QMix 3 minutes. Subsequently the teeth were prepared and three photomicrographs were obtained in each root third of root walls, by scanning electron microscopy. Two blinded and pre-calibrated examiners evaluated the images using a four-category scoring system. Data were statistically analyzed using Kruskal-Wallis and Dunn tests (p < 0.05). Results: There were differences among groups (p < 0.05). UAI showed better cleaning ability than EC (p < 0.05). There were improvements when QMix was used with auxiliary devices in comparison with conventional irrigation (p < 0.05). Conventional irrigation for 3 minutes presented significantly better results than its use for 1 minute (p < 0.05). Conclusions: QMix should be used for 1 minute when it is used with UAI, since this final irrigation protocol showed the best performance and also allowed clinical optimization of this procedure.

• Annals of Laboratory Medicine
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• 제38권6호
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• pp.495-502
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• 2018

Background: Molecular genetic abnormalities are observed in over 90% of chronic myelomonocytic leukemia (CMML) cases. Recently, several studies have demonstrated the negative prognostic impact of ASXL1 mutations in CMML patients. We evaluated the prognostic impact of ASXL1 mutations and compared five CMML prognostic models in Korean patients with CMML. Methods: We analyzed data from 36 of 57 patients diagnosed as having CMML from January 2000 to March 2016. ASXL1 mutation analysis was performed by direct sequencing, and the clinical and laboratory features of patients were compared according to ASXL1 mutation status. Results: ASXL1 mutations were detected in 18 patients (50%). There were no significant differences between the clinical and laboratory characteristics of ASXL1-mutated ($ASXL1^+$) CMML and ASXL1-nonmutated ($ASXL1^-$) CMML patients (all P >0.05). During the median follow-up of 14 months (range, 0-111 months), the overall survival (OS) of $ASXL1^+$ CMML patients was significantly inferior to that of $ASXL1^-$ CMML patients with a median survival of 11 months and 19 months, respectively (log-rank P =0.049). An evaluation of OS according to the prognostic models demonstrated inferior survival in patients with a higher risk category according to the Mayo molecular model (log-rank P =0.001); the other scoring systems did not demonstrate a significant association with survival. Conclusions: We demonstrated that ASXL1 mutations, occurring in half of the Korean CMML patients examined, were associated with inferior survival. ASXL1 mutation status needs to be determined for risk stratification in CMML.

• 동의신경정신과학회지
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• 제32권3호
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• pp.207-217
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• 2021

Objectives: The objective of this study was to perform a scoping review to describe clinical study trends on Qigong in order to identify further directions of Qigong in Korean medicine. Methods: Under the Arksey and O'Malley methodological framework, PubMed was searched to identify articles published from January 1, 2019 to June 28, 2021. A total of 224 articles were retrieved. Results were systematically filtered by two independent reviewers based on inclusion/exclusion criteria. Publication information, disease, intervention and research results of a total of 153 articles were extracted and analyzed. Results: Asia had the largest number of Qigong studies (82 studies, 65%). Most research studies were conducted in the academic field of Medicine (n=109, 86.5%), including Complementary and Alternative Medicine (n=35), Medicine (miscellaneous) (n=15), and Oncology (n=15). Based on ICD-10 classification, Mental and Behavioral Disorder (n=25, 19.8%) was the most frequently analyzed decease, followed by Neoplasm (n=24) and Disease of the Nervous system (n=12). Almost half of all studies were Systematic Reviews. RCTs only accounted for 25.4%. Interventions were very diverse and inconsistent. Sixty (47.6%) studies analyzed Qigong as a single intervention. In 66 cases, Qigong was analyzed as part of a large category such as Mind-Body intervention. Most studies designed a Donggong (動功) program. The age of the population was relatively high as 47.1% of all studies were conducted on middle aged or older adults. Conclusions: These findings suggest that further standardized research on Qigong, especially Junggong (靜功), needs to be conducted by developing research protocols and practice programs to verify effects of Qigong and utilize Qigong as a medical intervention in Korean Medicine.

• 한국기후변화학회지
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• 제7권4호
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• pp.443-450
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• 2016

The major greenhouse gases (GHGs) in agricultural sector are methane ($CH_4$), nitrous oxide ($N_2O$), carbon dioxide ($CO_2$). GHGs emissions are estimated by pertinent source category in a guideline book from Intergovernmental Panel on Climate Change (IPCC) such as methane from rice paddy, nitrous oxide from agricultural soil and crop residue burning. The methods for estimation GHGs emissions in agricultural sector are based on 1996 and 2006 IPCC guideline, 2000 and 2003 Good Practice Guidance. In general, GHG emissions were calculated by multiplying the activity data by emission factor. The total GHGs emission is $10,863Gg\;CO_2-eq$. from crop cultivation in agricultural sector in 2013. The emission is divided by the ratio of greenhouse gases that methane and nitrous oxide are 64% and 34%, respectively. Each gas emission according to the source categories is $7,000Gg\;CO_2-eq$. from rice paddy field, $3,897Gg\;CO_2-eq$. from agricultural soil, and $21Gg\;CO_2-eq$. from field burning, respectively. The GHGs emission in agricultural sector had been gradually decreased from 1990 to 2013 because of the reduction of cultivation. In order to compare with indirect emissions from agricultural soil, each emission was calculated using IPCC default factors (D) and country specific emission factors (CS). Nitrous oxide emission by CS applied in indirect emission, as nitrogen leaching and run off, was lower about 50% than that by D.

• Journal of Korean Dental Science
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• 제15권1호
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• pp.31-50
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• 2022

Purpose: This study was to investigate the types of imaging modalities, analytical methods for age estimation, and the age of the subjects in research on age estimation using dental radiography through a scoping review, and to investigate the overall trends in age estimation studies. Materials and Methods: A scoping review was designed according to the Arksey and O'Malley guidelines and the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. Three electronic databases were used as search sources (Medline, Embase, and Cochrane Library). Studies were classified according to the three main components of the research question. "What are the imaging modalities, analytical methods, and target age in dental imaging-based age estimation studies?" Result: The final 198 studies were selected by two reviewers. The most common imaging modality used in studies was panoramic radiography (69.7%), and studies using cone-beam computed tomography have increased over time. Analytical methods for age estimation were 62.6% in studies based on tooth development and 26.3% in studies using pulp/tooth ratio. The subject age was 27.8% for children and 27.3% for adults. Studies conducted in all age groups comprised the smallest category (5.2%). Conclusion: Panoramic radiography has been the most used types of imaging modalities for age estimation, and the most common analytical method was analysis of tooth development. Most studies targeted specific ages, and very few involved all age groups. Dental age estimation studies should be carried out with appropriate consideration of the imaging modality that is analyzed, the methods that are used, and the age that is targeted.

• 한국토양비료학회지
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• 제45권6호
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• pp.1143-1152
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• 2012

본 연구진은 2007년 농진청과 통계청에서 수집한 농축산물소득자료 통계 값으로 국가평균 탄소성적을 산정하는 top-down 방식의 자료수집 방법을 구축하였다. 또한, 본 연구진은 2011년 전북 군산 지역 관행농 쌀 생산 농가 중 벼 평균 재배면적이 3.3 ha인 네 곳의 대규모 생산농가를 섭외하여 면접조사로 사례를 분석하는 bottom-up 방식의 전과정 목록 (LCI, life cycle Inventory)도 구축하였다. 본 연구는 관행농 쌀 생산체계에 대한 전과정 평가를 국립농업과학원에서 구축한 top-down 방식과 사례분석을 통한 bottom-up 방식으로 수행한 결과를 비교하기 위하여 수행되었다. 전과정 목록분석 결과 $CO_2$은 무기질 비료 생산과 벼 재배과정에서 배출량이 가장 많았고, $CH_4$와 $N_2O$은 대부분 벼 재배과정에서 배출되었다. 관행농 쌀 1 kg 생산을 기준으로 하는 탄소성적은 국가평균값이 2.39E+00 kg $CO_2$-eq. $kg^{-1}$, 사례분석이 1.04E+00 kg $CO_2$-eq. $kg^{-1}$으로 국가평균 탄소성적이 사례분석보다 높았다. 쌀 생산 전과정에 투입되는 농자재량은 국가평균과 사례분석이 유사하거나 오히려 사례분석이 더 높게 나타났으나 작기 당 수확량이 높아 사례분석의 탄소성적이 유리한 결과가 나왔다. 관행농 쌀 생산체계에서 각 생산공정별 환경영향을 분석한 결과 화학비료 생산단계가 대부분의 환경영향범주에서 기여도가 가장 높게 나타났으나, GWP 범주는 벼 재배에 의한 환경영향 기여도가 가장 컸다. 관행농 쌀 생산에서 탄소성적을 결정하는 주요 요인은 논토양에서 발생하는 메탄가스와 비료투입량 및 벼 수확량이었다. 본 연구 결과는 향후 '농산물 저탄소인증' 시범사업에서 배출량 산정을 위한 기초자료와 벼논에서 온실가스를 줄이기 위한 영농법 개발에 활용될 것으로 기대된다. '저탄소 농산물 인증제도' 시범사업의 성공을 위해서 쌀을 포함한 농작물에 대한 실제 농가를 대상으로 하는 사례분석 연구가 더욱 늘어나야 할 것이다. 현 단계에서는 자발적인 참여 농가를 대상으로 하여 활동 데이터 수집을 늘리고, 자료의 일관성과 대표성 보완을 위하여 농가의 활동데이터를 수집할 때 모집단 선발과 수집기간 등에 대한 논의가 필요하다. 또한 현재 국립농업과학원에서 구축하고 있는 DB는 2007년 소득자료를 기준으로 하므로 인증사업 시행시 사례분석을 적용할 때 몇 가지 한계와 보완사항이 요구되었다. 첫째, 국가평균 통계와 실제 대상농가 간 품종 및 생산연도에 의한 생산량 차이를 보완하기 위한 가중치 적용 등이 필요할 것으로 판단되었다. 둘째, 현재 국가평균 DB를 기준으로 설정된 시스템 경계에서 육묘 용 상토와 볏짚 및 쌀겨 등 부산물과 수확 후 도정 및 포장 등에 대한 시스템경계 확장 연구 및 이에 관한 LCI DB 구축이 요구되었다.

• 한국지진공학회논문집
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• 제24권6호
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• pp.253-266
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• 2020

The extended slip-weakening model was investigated by using a compiled set of source-spectrum-related parameters, i.e. seismic moment M_o, S-wave velocity V_s, corner-frequency f_c, and source-controlled high-cut frequency fmax, for 113 shallow crustal earthquakes (focal depth less than 25 km, M_W 3.0~7.5) that occurred in Japan from 1987 to 2016. The investigation was focused on the characteristics of stress drop, radiation energy-to-seismic moment ratio, radiation efficiency, and fracture energy release rate, G_c. The scaling relationships of those source parameters were also investigated and compared with those in previous studies, which were based on generally used singular models with the dimensionless numbers corresponding to f_c given by Brune and Madariaga. The results showed that the stress drop from the singular model with Madariaga's dimensionless number was equivalent to the breakdown stress drop, as well as Brune's effective stress, rather than to static stress drop as has been usually assumed. The scale dependence of stress drop showed a different tendency in accordance with the size category of the earthquakes, which may be divided into small-moderate earthquakes and moderate-large earthquakes by comparing to M_o = 10¹⁷~10¹⁸ Nm. The scale dependence was quite similar to that shown by Kanamori and Rivera. The scale dependence was not because of a poor dynamic range of recorded signals or missing data as asserted by Ide and Beroza, but rather it was because of the scale dependent V_r-induced local similarity of spectrum as shown in a previous study by the authors. The energy release rate G_c with respect to breakdown distance D_c from the extended slip-weakening model coincided with that given by Ellsworth and Beroza in a study on the rupture nucleation phase; and the empirical relationship given by Abercrombie and Rice can represent the results from the extended slip-weakening model, the results from laboratory stick-slip experiments by Ohnaka, and the results given by Ellsworth and Beroza simultaneously. Also the energy flux into the breakdown zone was well correlated with the breakdown stress drop, ${\tilde{e}}$ and peak slip velocity of the fault faces. Consequently, the investigation results indicate the appropriateness of the extended slip-weakening model.