• Journal of Korea Trade
• /
• v.23 no.6
• /
• pp.66-92
• /
• 2019

Purpose - Foreign Exchange Rates (FER) have been one of the most significant factors for both Korean exporters and the economy of Korea. The purpose of this study is to evaluate whether exporters with a high level of Exchange Rate Elasticity of Sales (ERES) make the use of earnings management for Income Smoothing (IS). Design/methodology - Income smoothing was obtained using the methodology suggested by Leuz, Nanda and Wysocki (2003). Accruals-based Earnings Management (AEM) was estimated using Discretionary Accruals (DA) calculated by the operant Jones Model developed by Dechow, Sloan and Sweeney (1995). Real Earnings Management (REM) was obtained using the methodologies suggested by Roychowdhury (2006) and Cohen and Zarowin (2010). Data were 2,402 firm years of public listed companies on the KRX, which were not in the financial industry and had a settlement of accounts in December for the period from 2013 to 2017. Findings - Results of the evaluation are as follows. First, companies with higher levels of ERES have relatively lower levels of smoothing of reported income. This might be because a fluctuation in sales caused by an exchange rate fluctuation has a direct impact on the volatility of the reported income. Second, companies with high levels of both ERES and IS have a positive correlation with both AEM and REM. This might be because companies with high levels of IS engage in earnings management to smooth reported income. Specifically, it is possible to assume that for smoothing the reported income, not only AEM but also REM is practiced. Third, companies with high levels of ERES but low levels of IS have a negative correlation with both AEM and REM. This could be interpreted as companies exhibiting low levels of IS due to higher levels of ERES tend to control IS. In addition, such results were supported by firms relying highly on exporting, and are consequently sensitive to exchange rate fluctuation. Therefore, it may conclude that companies with high levels of ERES make the use of earnings management as a means of IS. Originality/value - This study can find its significance from the fact that it is the first study, empirically verifying that companies of Korea, where exportation is a large part, use both AEM and REM as a means for smoothing reported income upon facing exchange rate fluctuations. In addition, it is highly expected that the results of this study could be useful for participants of financial markets when making IS-related decisions.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.18 no.2
• /
• pp.55-61
• /
• 2018

Orinithine transcarbamylase (OTC) deficiency is the most common inborn error of the urea cycle with resulting hyperammonemia, which is medical emergency in newborns.We recently had a case of a boy that presented with lethargy, seizure, hyperammonemia and hypocalcemia in neonatal period. He was diagnosed with OTC deficiency by two consequent ways which are initial biochemical phenotype including hyperammonemia and an increased orotic acid in his urine and genetic analysis of the OTC gene. The OTC gene showed a novel hemizygous mutation c.913C>T (p.Pro305Ser). He was treated by low protein intake, sodium benzoate, phenylbutyrate sodium, L-arginine, and continuous renal replacement therapy (CRRT). After discharge, he has a relatively good prognosis without notable developmental delay. For good prognosis, the duration of hyperammonemia should be shorten. And it can be reached by an early diagnosis. For early detection of OTC deficiency, targeted exome sequencing will be a important role as well as biochemical tests.

• Journal of the Korean Society of Mineral and Energy Resources Engineers
• /
• v.55 no.6
• /
• pp.635-648
• /
• 2018

This study analyzed patent trends of seismic nodal systems and the technical characteristics of core patents of three major companies, including Fairfield, Sercel, and Wireless Seismic, to examine the focus of technology development of each company. From the analysis, the patent application growth rate of seismic nodal systems has steadily increased since early to mid-2000s and has recently shown a higher growth rate. Over the same period, the patent application growth rate of the three major companies examined was higher than that of the global trend, and patent infringement cases was also examined to evaluate market competition in this field. Analysis of the technical characteristics of the three companies' 33 core patents showed that they are generally focused on seismic signal detection. Sub-technologies included improved reliability of data acquisition, data transmission efficiency, and overall operating of the seismic nodal system. New entrants in field of technology development or manufacturing of seismic nodal systems where the market is growing must closely analyze the contents of major companies' products and patents to prevent possible patent disputes or duplicate research.

• Korean Journal of Remote Sensing
• /
• v.34 no.6_2
• /
• pp.1273-1282
• /
• 2018

Recently, active research on the Arctic Ocean has been conducted due to the influence of global warming and new Arctic ship route. Although previous studies already calculated quantitative extent of sea ice using passive microwave radiometers, melting at the edge of sea ice and surface roughness were hardly considered due to low spatial resolution. Since Sentienl-1A/B data in Extended Wide (EW) mode are being distributed as free of charge and bulk data for Arctic sea can be generated during a short period, the entire Arctic sea ice data can be covered in high spatial resolution by mosaicking bulk data. However, Sentinel-1A/B data in EW mode, especially in HV polarization, needs significant radiometric correction for further classification. Thus, in this study, we developed algorithms that can correct thermal noise and scalloping effects, and confirmed that Arctic sea ice and open-water were well classified using the corrected dual-polarization SAR data.

• Korean Journal of Remote Sensing
• /
• v.34 no.6_2
• /
• pp.1229-1238
• /
• 2018

We examined if a state of sea-ice in Bering Sea acts as a prelude of variation in that of Chukchi Sea by using satellites-based Arctic sea-ice concentration time series. Datasets consist of monthly values of sea-ice concentration during 36 years (1982-2017). Time series analysis armed with Transfer entropy is performed to describe how sea-ice data in Chukchi Sea is affected by that in Bering Sea, and to explain the relationship. The transfer entropy is a measure which identifies a nonlinear coupling between two random variables or signals and estimates causality using modification of time delay. We verified this measure checked a nonlinear coupling for simulated signals. With sea-ice concentration datasets, we found that sea-ice in Bering Sea is influenced by that in Chukchi Sea 3, 5, 6 months ago through the transfer entropy measure suitable for nonlinear system. Particularly, when a sea-ice concentration of Bering Sea has a local minimum, sea ice concentration around Chukchi Sea tends to decline 5 months later with about 70% chance. This finding is considered to be a process that inflow of Pacific water through Bering strait reduces sea-ice in Chukchi Sea after lowering the concentration of sea-ice in Bering Sea. This approach based on information theory will continue to investigate a timing and time scale of interesting patterns, and thus, a coupling inherent in sea-ice concentration of two remote areas will be verified by studying ocean-atmosphere patterns or events in the period.

• Yonsei Medical Journal
• /
• v.59 no.9
• /
• pp.1026-1033
• /
• 2018

Purpose: Consistent evidence indicates that cervical and breast cancer screening rates are low among socioeconomically deprived women. This study aimed to assess trends in cervical and breast cancer screening rates and to analyze socioeconomic inequalities among Korean women from 2005 to 2015. Materials and Methods: Data from the Korean National Cancer Screening Survey, an annual nationwide cross-sectional survey, were utilized. A total of 19910 women were finally included for analysis. Inequalities in education and household income status were estimated by slope index of inequality (SII) and relative index of inequality (RII), along with calculation of annual percent changes (APCs), to show trends in cancer screening rates. Results: Cervical and breast cancer screening rates increased from 54.8% in 2005 to 65.6% in 2015 and from 37.6% in 2005 to 61.2% in 2015, respectively. APCs in breast cancer screening rates were significant among women with higher levels of household income and education status. Inequalities by household income in cervical cancer screening uptake were observed with a pooled SII estimate of 10.6% (95% CI: 8.1 to 13.2) and RII of 1.4 (95% CI: 1.3 to 1.6). Income inequalities in breast cancer screening were shown to gradually increase over time with a pooled SII of 5.9% (95% CI: 2.9 to 9.0) and RII of 1.2 (95% CI: 0.9 to 1.3). Educational inequalities appeared to diminish over the study period for both cervical and breast cancer screening. Conclusion: Our study identified significant inequalities among socioeconomically deprived women in cervical and breast cancer screening in Korea. Especially, income-related inequalities were greater than education-related inequalities, and these were constant from 2005 to 2015 for both cervical and breast cancer screening.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.40 no.3
• /
• pp.187-193
• /
• 2022

In the Yeongdong region of Gangwon-do, coastal areas are important resources in terms of cultural, social and economic aspects. However, the coast of Gangwon-do is experiencing severe erosion, and it is concerned that its adverse effects will gradually increase. In this study, coastline changes of Yangyang and Gangneung in Gangwon-do were tracked and analyzed over a long period of time. In order to build time series image data, aerial photos from the 1940s to the present were mainly used, and data from CORONA satellite, which operated from the 1960s to the early 1970s, were collected and used together. Using 51cm resolution ortho image and 2m resolution Digital Elevation Model(DEM) as reference, ground control points were selected to perform geometric correction on the aerial photos and CORONA images. Subsequently, Canny edge detector applied to these images to extract the coastlines. As a result of analyzing the extracted and vectorized coastlines by overlaying them in chronological order, erosion and deposition occurring around the artificial structures and on the nearby beaches were observed. In this study, the effect of seasonal variation, tide, and various coastal management including the beach filling were not considered. Because coastal erosion is greatly affected by geographic factors, each local government must find its own solution. Continuous research and local data accumulation are required.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.24 no.2
• /
• pp.95-114
• /
• 2022

This study presented the possibility of automatic frost observation and the related image data acquisition through the design and installation of a Multiple-sensor based Frost Observation System (MFOS). The MFOS is composed of an RGB camera, a thermal camera and a leaf wetness sensor, and each device performs complementary roles. Through the test operation of the equipment before the occurrence of frost, the voltage value of the leaf wetness sensor increased when maintaining high relative humidity in the case of no precipitation. In the case of Gapyeong- gun, the high relative humidity was maintained due to the surrounding agricultural waterways, so the voltage value increased significantly. In the RGB camera image, leaf wetness sensor and the surface were not observed before sunrise and after sunset, but were observed for the rest of the time. In the case of precipitation, the voltage value of the leaf wetness sensor rapidly increased during the precipitation period and decreased after the precipitation was terminated. In the RGB camera image, the leaf wetness sensor and surface were observed regardless of the precipitation phenomenon, but the thermal camera image was taken due to the precipitation phenomenon, but the leaf wetness sensor and surface were not observed. Through, where actual frost occurred, it was confirmed that the voltage value of leaf wetness sensor was higher than the range corresponding to frost, but frost was observed on the surface and equipment surface by the RGB camera.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.64 no.3
• /
• pp.9-24
• /
• 2022

Currently, a vast amount of hydrologic data is accumulated in real-time through automatic water level measuring instruments in agricultural reservoirs. At the same time, false and missing data points are also increasing. The applicability and reliability of quality control of hydrological data must be secured for efficient agricultural water management through calculation of water supply and disaster management. Considering the characteristics of irregularities in hydrological data caused by irrigation water usage and rainfall pattern, the Korea Rural Community Corporation is currently applying the Hampel filter as a water level data quality management method. This method uses window size as a key parameter, and if window size is large, distortion of data may occur and if window size is small, many outliers are not removed which reduces the reliability of the corrected data. Thus, selection of the optimal window size for individual reservoir is required. To ensure reliability, we compared and analyzed the RMSE (Root Mean Square Error) and NSE (Nash-Sutcliffe model efficiency coefficient) of the corrected data and the daily water level of the RIMS (Rural Infrastructure Management System) data, and the automatic outlier detection standards used by the Ministry of Environment. To select the optimal window size, we used the classification performance evaluation index of the error matrix and the rainfall data of the irrigation period, showing the optimal values at 3 h. The efficient reservoir automatic calibration technique can reduce manpower and time required for manual calibration, and is expected to improve the reliability of water level data and the value of water resources.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.26 no.6
• /
• pp.175-181
• /
• 2022

The condition of infrastructure deteriorates as the service life increases. Since most infrastructure in South Korea were intensively built during the period of economic growth, the proportion of outdated infrastructure is rapidly increasing now. Aging of such infrastructure can lead to safety accidents and even human casualties. To prevent these issues in advance, periodic and accurate inspection is essential. For this reason, the need for research to detect various types of damage using computer vision and deep learning is increasingly required in the field of remotely controlled or autonomous inspection. To this end, this study proposed a neural network structure that can detect concrete damage by classifying it into three types. In particular, the proposed neural network can detect them more accurately through a hierarchical learning technique. This neural network was trained with 2,026 damage images and tested with 508 damage images. As a result, we completed an algorithm with average mean intersection over union of 67.04% and F1 score of 52.65%. It is expected that the proposed damage detection algorithm could apply to accurate facility condition diagnosis in the near future.