• Journal of Electrochemical Science and Technology
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• 제10권2호
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• pp.104-114
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• 2019

Energy is an essential driving force for modern society. In particular, electricity has become the standard source of power for almost every aspect of life. Electric power runs lights, televisions, cell phones, laptops, etc. However, it has become apparent that the current methods of producing this most valuable commodity combustion of fossil fuels are of limited supply and has become detrimental for the Earth's environment. It is also self-evident, given the fact that these resources are non-renewable, that these sources of energy will eventually run out. One of the most promising alternatives to the burning of fossil fuel in the production of electric power is the proton exchange membrane (PEM) fuel cell. The PEM fuel cell is environmentally friendly and achieves much higher efficiencies than a combustion engine. Water management is an important issue of PEM fuel cell operation. Water is the product of the electrochemical reactions inside fuel cell. If liquid water accumulation becomes excessive in a fuel cell, water columns will clog the gas flow channel. This condition is referred to as flooding. A number of researchers have examined the water removal methods in order to improve the performance. In this paper, a new water removal method that investigates the use of vibro-acoustic methods is presented. Piezo-actuators are devices to generate the flexural wave and are attached at end of a cathode bipolar plate. The "flexural wave" is used to impart energy to resting droplets and thus cause movement of the droplets in the direction of the traveling wave.

• The Journal of Asian Finance, Economics and Business
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• 제9권6호
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• pp.231-243
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• 2022

The objective of this study is to analyze the impact of conservative financial reporting on investment during uncertainty. It was assumed that during uncertainty conservative financial reporting can play an important role to improve investment decision-making. For our analysis, data sets from 2005-2020 of nonfinancial companies are used. To measure the impact of conservative financial reporting in the non-financial sector of Pakistan, Khan and Watts' (2009) model is applied. "Prospector" and "Defender" Business strategy is applied for measuring firm-level uncertainty. Investment is measured by adding the change in fixed assets (property, plant, and equipment). To check the robustness of conservative financial reporting, Givoly and Hayn's (2000) Negative Accruals measure is applied. To measure the robustness of uncertainty, environmental scanning and alertness technique is applied. According to environmental scanning and alertness technique, companies are divided into two groups named 'inert' and 'alert'. 'Inert' are those firms that are not scanning their environment, and 'alert' are those firms who continuously analyze their environment. The empirical estimations support our hypothesis. The empirical findings provide the proof that in the wake of uncertainty conservative financial reporting may facilitate to take optimal investment decisions in the developing economy of Pakistan. Our results provide critical and practical implications for investors, researchers, and standard setters.

• Genomics & Informatics
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• 제19권3호
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• pp.21.1-21.5
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• 2021

The use of social media data, like Twitter, for biomedical research has been gradually increasing over the years. With the coronavirus disease 2019 (COVID-19) pandemic, researchers have turned to more non-traditional sources of clinical data to characterize the disease in near-real time, study the societal implications of interventions, as well as the sequelae that recovered COVID-19 cases present. However, manually curated social media datasets are difficult to come by due to the expensive costs of manual annotation and the efforts needed to identify the correct texts. When datasets are available, they are usually very small and their annotations don't generalize well over time or to larger sets of documents. As part of the 2021 Biomedical Linked Annotation Hackathon, we release our dataset of over 120 million automatically annotated tweets for biomedical research purposes. Incorporating best-practices, we identify tweets with potentially high clinical relevance. We evaluated our work by comparing several SpaCy-based annotation frameworks against a manually annotated gold-standard dataset. Selecting the best method to use for automatic annotation, we then annotated 120 million tweets and released them publicly for future downstream usage within the biomedical domain.

• The Journal of Asian Finance, Economics and Business
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• 제9권4호
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• pp.39-52
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• 2022

This study examines whether accounting conservatism can support real earnings management by reducing accrual earnings management techniques. The net impact of conservative reporting on earnings management is also analyzed. It is assumed that moderating the role of conservative financial reporting during uncertainty can mitigate earnings management practices. For our analysis, 5354 firm-year observations for the period 2007-2020 of nonfinancial companies listed on the Pakistan Stock Exchange are applied. To measure conservatism in the non-financial sector of Pakistan, Khan and Watts' (2009) model is used to provide evidence that conservatism is a way to restrict earnings management during uncertainty. "Prospector" and "Defender" Business strategy is applied for measuring firm-level uncertainty. To measure accrual earnings management Modified Jones (1995) model and Dechow and Dichev (2002) approach and Kasznik (1999) model are applied, and for real earnings management Roychowdhury model is applied which follows three approaches to measure real earnings management i.e. cash flow manipulation, Overproduction, and discretionary expenses. The estimations support our hypothesis by providing statistically significant proof that conservative financial reporting in a developing economy like Pakistan may be used to overcome the net impact of earnings management during uncertainty. Our results provide critical and practical implications for investors, researchers, and standard setters.

• 한국사회정책
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• 제24권4호
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• pp.113-150
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• 2017

본 연구는 노동자가 업무 이외의 이유로 아프게 되면, 노동시장에서 어떻게 고용 불안정성을 경험하고 또 빈곤화를 경험하는지 분석한다. 특히 아픈 노동자에 대한 한국 사회보장제의 소득보장 기능을 분석하고, 상병수당이 부재한 한국 복지국가의 특수성이 아픈 노동자의 빈곤화에 미치는 영향에 주의를 기울이며 사례 연구를 실시했다. 연구 결과, 아픈 노동자들은 상병으로 고통을 경험해도 일단 '아파도 참는다'. 특히 불안정 노동을 하는 비정규직 노동자들은 아프면 몸을 회복할 수 있는 휴직을 누릴 수 있는 여지가 없이 실직을 경험하게 된다. 그리고 아파서 실직을 경험하게 되어도 소득 감소분을 채우기 위해 더 불안정한 노동이라도 지속하는 경향이 있었다. 그 과정에서 가족 등 주변 사회적 자원이 무너지는 양상도 보이면서, 빈곤화의 경로를 밟는 것이 관찰됐다. 상병과 실업이라는 복합적인 위기에 처한 노동자를 위한 사회보장제도에도 사각지대가 확인됐다. 산재를 겪은 노동자들은 산업재해 신고를 기피하는 사업주 탓에 제도의 혜택에서 벗어나기도 하였고 또 상병으로 실직한 노동자를 고용주가 '자발적 실업'으로 신고하여 실업수당에도 배제됐다. 본 연구는 노동자의 상병으로 인한 일자리 불안정화와 빈곤화 과정을 구체적으로 확인하는 연구로 의의가 있다. 또한 상병수당의 부재와 아픈 노동자의 관계가, 상병수당을 포함하여 한국 소득보장제에 어떠한 학술적, 정책적 함의를 가지는지 고찰했다.

• Child Studies in Asia-Pacific Contexts
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• 제5권2호
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• pp.95-105
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• 2015

We developed a test of English silent word reading, following work by Mather, Hammill, Allen and Roberts (2004) and Bell, McCallum, Krik, Fuller, and McCane-Bowling (2007), in order to tap Hong Kong Chinese children's reading of English as a foreign language. We created one subtest of individual word reading and another of word reading contextualized within sentences; together, these tests require no more than 10 minutes for administration. In Study 1, we administered the entire test to 552 second grade Hong Kong Chinese children between the ages of 70 and 121 months old, from five different primary schools. The association between the subtests of English silent word reading and contextual reading was positively correlated (.78). In Study 2, 77 Hong Kong Chinese second graders were tested on our newly developed English silent word reading test, together with non-verbal IQ, an English word reading and a Chinese character recognition test (both read aloud). With age and non-verbal IQ statistically controlled, there was a significant correlation between English silent word reading and the more standard English word reading, read aloud, (.78); the association between English silent word reading and Chinese character recognition was also positively correlated (.49). This newly created test is a quick and reliable measure, suitable for both educators and researchers to use to identify poor readers who learn English as a foreign or second language.

• Journal of information and communication convergence engineering
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• 제9권5호
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• pp.577-582
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• 2011

EMR(Electronic Medical Record) is an emerging technology that is highly-blended between non-IT and IT area. One of methodology to link non-IT and IT area is to construct databases. Nowadays, it supports before and after-treatment for patients and should satisfy all stakeholders such as practitioners, nurses, researchers, administrators and financial department and so on. In accordance with the database maintenance, DAS (Data as Service) model is one solution for outsourcing. However, there are some scalability and strategy issues when we need to plan to use DAS model properly. We constructed three kinds of databases such as plain-text, MS built-in encryption which is in-house model and custom AES (Advanced Encryption Standard) - DAS model scaling from 5K to 2560K records. To perform custom AES-DAS better, we also devised Bucket Index using Bloom Filter. The simulation showed the response times arithmetically increased in the beginning but after a certain threshold, exponentially increased in the end. In conclusion, if the database model is close to in-house model, then vendor technology is a good way to perform and get query response times in a consistent manner. If the model is DAS model, it is easy to outsource the database, however, some technique like Bucket Index enhances its utilization. To get faster query response times, designing database such as consideration of the field type is also important. This study suggests cloud computing would be a next DAS model to satisfy the scalability and the security issues.

• 한국콘텐츠학회논문지
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• 제12권12호
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• pp.385-394
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• 2012

본 연구에서는 총수 및 그 일가에 의해 절대적인 영향력을 받고 있는 대규모기업집단이 그렇지 않은 기업에 비해 이익조정행위에 차별적으로 관여하는지 고찰한다. 본 연구는 선행연구에서 간과한 기업특성 및 잠재적 이분산에 기인한 내생성 문제를 통제하고자, 1992년부터 2010년까지 19년 동안 268개의 기업이 반복적으로 관찰되는 패널데이터를 이용한 확률효과 GLS 분석을 수행하였고, 추가분석에서는 잠재적 이분산성을 통제하고자 Hausman and Taylor검증을 실시하였다. 본 연구의 결과를 요약하면 다음과 같다. 재벌집단에 속해 있는 기업들의 발생액을 이용한 이익조정행위는 그렇지 않은 기업들의 이익조정행위 수준과 유의한 차이를 보이지 않는 것으로 나타난 반면 실제이익조정행위를 덜 행하는 것으로 나타났다. 이는 미래경영성과 및 장기주가에도 부정적인 영향을 미치고, 기업가치 또한 크게 오인시키는 실제이익조정행위를 대규모집단이 회피한다는 것으로 해석할 수 있다. 본 연구는 재벌기업의 장기간 시계열특성과 횡단면적 특성을 동시에 고려한 패널데이터를 이용하여, 재벌기업과 이익조정의 관련성에 대한 보다 신뢰할 수 있는 결과를 제공했다는 점에서 의미가 크다고 할 수 있다.

• 한국산업보건학회지
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• 제20권1호
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• pp.63-69
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• 2010

This study was conducted to compare the concentration of various air contaminants in nine different laboratories during routine activities. Volatile organic compounds (VOC) were sampled and analyzed using NIOSH Method 1500 and asbestos fibers were sampled and analyzed using NIOSH Method 9002 and 7400. Detectable levels of acetone, toluene and ethanol were found in all the laboratories and xylene and n-hexane were detected in eight of the nine laboratories. All the VOC concentrations were well below the Korean Ministry of Labor's Exposure Limit and American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Values (TLVs). Total VOC concentrations at the university laboratories were significantly higher than those at governmental agency laboratories. Airborne fiber concentrations were below 0.01 fibers/cc, while the concentration of chrysotile was 2% in insulation materials sprayed on the ceiling of one laboratory. While all the governmental agency laboratories (n=4) had fume hoods, two out of the five university laboratories did not have fume hoods. The capture velocity of half of the fume hoods were below the maintenance standard(0.4 m/sec). In conclusion, the study suggests that the current controls in place at both university and government agency laboratories are not sufficient in limiting exposure to harmful chemicals to non-detectable levels, though they appear to be adequate in protecting workers to levels below applicable occupational exposure limits. The study also suggests that researchers working in university laboratories may be exposed to greater levels of contaminant than those working in government agency laboratories.

• 한국정밀공학회지
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• 제24권8호통권197호
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• pp.116-121
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• 2007

The length of root canal has to be measured for endodontic treatment. Several electronic apex locators were developed to measure the length of root canal by other researchers. And their accuracies were verified by X-ray or micrometer method. But these methods did not consider the non-linear bends of pulp and had ${\pm}0.5mm$ error which was large enough to measure the length of root canal. The purpose of this study is the introduction of a new method to measure the length of root canal and the verification of the accuracy of an electronic apex locator using a Micro-CT. The length of root canal of 6 teeth were measured with the electronic apex locator. When the electronic apex locator reads 0.5, 0.6, 0.7, 0.8, 0.9 and 1.0 mm length of the file which was inserted in the hole of the tooth to measure the length of root canal. The average (${\pm}$Standard deviation) length of root canal of 6 teeth measured by the Micro-CT was $0.49{\pm}0.03,\;0.59{\pm}0.04,\;0.68{\pm}0.03,\;0.78{\pm}0.03,\;0.90{\pm}0.04\;and\;1.01{\pm}0.03mm$, respectively. The maximum error of the electronic apex locator was 0.06 mm.