• Journal of Korea Trade
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• v.26 no.2
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• pp.21-44
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• 2022

Purpose - This study quantifies sources of trade balance dynamics over the business cycle in Korea. Specifically, we quantify the relative importance of domestic and foreign factors on trade balance dynamics using a small open economy real business cycle (SOE-RBC) model and provide policy implications for stabilization policies. Aggregate productivity and interest rate spreads are considered domestic factors affecting the trade balance. A world interest rate (the U.S. interest rate) is considered a foreign factor. Design/methodology - Following Neumeyer and Perri (2005), we build the SOE-RBC model with three types of shocks: aggregate productivity, interest rate spread, and world interest shocks. The model is estimated by the generalized method of moments (GMM) using relevant business cycle statistics. The estimated model is used for quantifying the relative importance of domestic and foreign factors on trade balance dynamics in Korea. Findings - Our main findings can be summarized as follows: 85.64% of the trade balance fluctuations in Korea are explained by domestic factors, the remaining 14.35% by foreign factors. Particularly, trade balance dynamics are mostly accounted for by the change in aggregate productivity shocks (85.58%). World interest rate shocks considerably explain trade balance (14.35%), whereas the role of interest rate spread shocks that represent domestic risks is limited (0.08%). Although aggregate productivity is key in explaining trade balance dynamics in Korea, interest rates still have an essential role. This is because aggregate productivity changes induce interest rate spread variations and, thus, the trade balance significantly. The results suggest that government policies mitigating fluctuations in aggregate productivity would be effective for stabilization policies in Korea by reducing the trade balance volatility. Originality/value - Existing studies on the emerging market business cycle examine mostly Latin American countries, and the main object of the studies is the volatility of consumption rather than trade balance dynamics. Conversely, our study examines Korea rather than Latin American countries. Additionally, we examine sources of trade balance dynamics, which are relatively more important in Korea, rather than those of the volatility of consumption. Hence, we estimate the model to explicitly match moments related to trade balance in the data.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.16-29
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• 2017

It is known that large-scale deforestation has occurred in North Korea due to economic failures since the 1990s, and this is expected to greatly change the characteristics of the hydrological cycle. In this study, hydrological cycle simulation was carried out for the period of about 30 years from 1981 to 2013 for the entire Korean peninsula using the VIC model, a land surface hydrology model. The simulation results are summarized as follow. First, the runoff ratio is 55%~70% in South Korea and 38~56% in North Korea. In particular, it is worth noting that despite the small runoff ratio, the variation is about 28% larger than the South Korea's 15%. The rate of evapotranspiration was larger than that of South Korea. That is, the rate of evapotranspiration in South Korea is 20~35% and in North Korea it is 25~46%. However, the rate of change was 21% in the case of North Korea and slightly larger than 15% in South Korea. Third, South Korea has an average of 34% in soil moisture and 27% in North Korea. However, unlike the simulated results of the runoff ratio and the evapotranspiration rate, the difference in the variation of soil moisture in South Korea and North Korea over the entire period was similar with 8%. As a result, we can confirm that the difference of hydrological cycle characteristics between South Korea and North Korea has been increased since the 1990s, when the forest destruction of North Korea became serious. In the case of South Korea, there is little difference in the hydrological cycle characteristics. In North Korea, however, there is a distinct difference, which is also a result reflecting the difference in the effects of forest destruction.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.124-129
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• 2015

An experimental study was performed estimating COP(Coefficient of Performance) of air-conditioning cycle using inverter scroll compressor with and without $Al_2O_3$ nano particle. All experiments were done for various compressor speeds from 1000~4000 rpm and used the inverter controller called CANDY to change the compressor rpm. The air-conditioning cycle components in the apparatus were used as same with components of YF hybrid car. To estimate the COP, this study measured the temperature and pressure at inlets and outlets of compressor, condenser, and evaporator. And also measured the compressor input power using Powermeter. Through the experiments, the maximum error to estimate COP was shown about ${\pm}6.09%$ at 3500rpm. The COP of refrigeration cycle with $Al_2O_3$ nano-particle was similar with that of the base cycle without nano-particle between 1000~3000 rpm of the compressor speed. But, This study showed that the COP of the cycle with $Al_2O_3$ over 3000 rpm of the compressor speed was higher than that of the base cycle due to the higher heat transfer rate increased in the evaporator from the higher oil flow rate inside the cycle as well known. Those results can be used the basic and fundamental data to design the air-conditioning cycle using inverter scroll compressor with $Al_2O_3$ nano particle.

• KIEAE Journal
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• v.14 no.2
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• pp.69-75
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• 2014

Building has been deteriorated over the year after construction. The deterioration has caused to hinder the living condition and to decrease the building value. Thus, it is important to prevent or delay the building deterioration as well as to proceed the maintenance. The long-term repair program for the apartment in Korea plays a key role to make the repair plan after construction and to assure the function decent. This is not flexible to the change of the material and component because the program is provided by the Korean-law. Many items are omitted in the long-term program so that the maintenance experts face many difficulties to make a repair plan. In this paper, it aimed at providing the repair cycle and repair ratio according to the repair scope, which are not provided in the current program. This study shows that the repair ratio is presented with quartile range in 25%, 50%, 75% and 100%. This has an advantage to take an overall look in repair items. Under this presentation of the repair ratio, each item has a unique repair value. Second, the repair scope is divided into partly repair, fully repair, partly alteration and fully alteration. If a fully repair has a repair ratio close to 100%, it would mean that a fully repair is a fully alteration. Third, the short repair cycle means that it requires to maintain the function or performance of the components in a short term.

• Journal of Information Processing Systems
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• v.17 no.5
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• pp.972-988
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• 2021

At present, DevOps environments are getting popular in software organizations due to better collaboration and software productivity over traditional software process models. Software artefacts in DevOps environments are vulnerable to frequent changes at any phase of the software development life cycle that create a continuous integration continuous delivery pipeline. Therefore, software artefact traceability management is challenging in DevOps environments due to the continual artefact changes; often it makes the artefacts to be inconsistent. The existing software traceability related research shows limitations such as being limited to few types of artefacts, lack of automation and inability to cope with continuous integrations. This paper attempts to overcome those challenges by providing traceability support for heterogeneous artefacts in DevOps environments using a prototype named SAT-Analyser. The novel contribution of this work is the proposed traceability process model consists of artefact change detection, change impact analysis, and change propagation. Moreover, this tool provides multi-user accessibility and is integrated with a prominent DevOps tool stack to enable collaborations. The case study analysis has shown high accuracy in SAT-Analyser generated results and have obtained positive feedback from industry DevOps practitioners for its efficacy.

• Asian Journal of Innovation and Policy
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• v.11 no.2
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• pp.202-221
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• 2022

The media has depicted an abrupt socio-technological change in the Republic of Korea with the 4th Industrial Revolution. Because technologies cannot realize their potential without social acceptance, studying conflicts incurred by such a change is imperative. However, little literature has focused on conflicts caused by technologies. Therefore, the current study investigated media coverage regarding conflicts related to the 4th Industrial Revolution from 2016 to 2020 in the Republic of Korea, applying text-mining techniques. We found that the overall amount and coverage pattern conforms to the issue attention cycle. Also, the three major topics ("SMEs & Startups," "Mobility Conflict," and "Human & Technology") indicate quarrels between conflicting social entities. Moreover, the temporal change in media coverage implies the political use of the term rather than technological. However, we also found the media's deliberative discussion on the socio-technological impact. This study is significant because we expanded the discussion on media coverage of technologies to the realm of social conflicts. Furthermore, we explored the news articles of the recent five years with a text-mining approach that enhanced the objectivity of the research.

• The Plant Pathology Journal
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• v.32 no.3
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• pp.260-265
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• 2016

We observed the changes in aggressiveness and fecundity of the anthracnose pathogen Colletotrichum acutatum on hot pepper, under the ambient and the twice-ambient treatments. Artificial infection was repeated over 100 cycles for ambient ($25^{\circ}C/400ppm$ $CO_2$) and twice-ambient ($30^{\circ}C/700ppm$ $CO_2$) growth chamber conditions, over 3 years. During repeated infection cycles (ICs) on green-pepper fruits, the aggressiveness (incidence [% of diseased fruits among 20 inoculated fruits] and severity [lesion length in mm] of infection) and fecundity (the average number of spores per five lesions) of the pathogen were measured in each cycle and compared between the ambient and twice-ambient treatments, and also between the early (ICs 31-50) and late (ICs 81-100) generations. In summary, the pathogen's aggressiveness and fecundity were significantly lower in the late generation. It is likely that aggressiveness and fecundity of C. acutatum may be reduced as global $CO_2$ and temperatures increase.

• Journal of the korean society of oceanography
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• v.37 no.3
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• pp.144-153
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• 2002

This is a review paper, assessing progress reported in a Special Issue (Prandle and Lane, 2000) of Coastal Engineering focusing on simulation of SPM in the North Sea, against issues over a diverse range of shelf seas and their coastal margins. The broad objectives of reproducing the characteristics of sediment fluxes off an open coast and relating these to tidal and wave forcing were achieved. However, accurate computation of these fluxes remains sensitive to largely empirical coefficients used in determining erosion and deposition rates. Bed roughness strongly influences both these coefficients and the associated near-bed current magnitudes (including wave impact thereon). Bed roughness can change significantly over a tidal cycle and dramatically over seasons or in the course of a major event. Accurate simulation of sediment fluxes on a day-to-day basis is constrained by dependency on the initial distribution of mobile sediments. The latter depends on rates and locations of original sources and the time history of preceding events. Remote sensing via aircraft could provide data for assimilation into such models to circumvent these constraints. The approaches described here can be readily applied to other coastal regions to indicate the likely distributions and pathways of known sediment sources. However quantitative simulations will require an associated observational programme. A subsequent stage is to understand the evolving balance between the forecasted sediment movement - the resulting morphological adjustments and thence modifications to the prevailing tidal current and wave regimes.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.3
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• pp.71-79
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• 2008

Generally the price of agricultural products has much different characteristics from that of manufacturing products. If products have the limitation of long-term storage and the short period of cultivation, the price of products can be more unstable. Moreover, the price forecasting is very difficult because it doesn't follow any cycle or trend. However price can be regarded as risk instead of uncertainty if we can calculate the probability of price. Reliability analysis techniques are used for forecasting the price change of Chinese cabbage. This study aims to show the usability of reliability analysis for price forecasting. A price-forecasting model was developed based on weather data of the first 10 days of the full cultivating cycle (80 days) 70 days and the average price and standard deviation of wholesale market prices from 1996 to 2001 and applied to forecast the boom price, or the orice which is over the tolerance of market prices, of upland Chinese cabbage in 2002 and 2003. Applied results showed the possibility of boom price forecasting using reliability analysis techniques.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.4-4
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• 2020

Three wildfires severely damaged local towns and forests in Gangwon-do, South Korea in 2019 April 4-5. Local hydrological regime could be greatly altered by the wildfires, therefore it is important to assess its damage (e.g. area and severity) and also resultant changes in hydrological fluxes. We retrieved the Normalized-Burned Ratio (NBR) index using remote-sensing data (Moderate Resolution Imaging Spectroradiometer (MODIS) 500-m 8-day surface reflectance data), and delineated the damaged-area based on the difference in the NBR (dNBR) before and after the wildfires. We then estimated changes in the annual evapotranspiration (AET) in 2019 using the MODIS evapotranspiration data (500-m 8-day). It was found that the damaged-area of the three wildfires was 29.50 km^2 in total, which take up 1.00-6.19% area of five catchments. It was estimated that the AET would be decreased as 0.05-1.56% over those five catchments, as compared to the pre-fire AET (2004-2018). The impact of the wildfires on the catchment AET was less severe than expected (i.e. up to 1.56%) mostly because two big wildfires were distributed across two catchments respectively (i.e. four catchments for the two wildfires) and the other wildfire was small and not severe. This study highlights the importance of assessing the area and severity of a wildfire when estimating its impact on the local hydrological cycle.