• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.5
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• pp.555-560
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• 2014

In order to improve spectrum sensitivity of photodiode for detection of the laser wavelength at 850 nm ~ 1000 nm of near-infrared band, this study has produced silicon-based photodiode whose area is $5000{\mu}m{\times}2000{\mu}m$, and the thickness is $280{\mu}m$. It was packed by the TO-5 type. The electrical properties of the dark currents have valued of approximately 0.1 nA for 5 V reverse bias, while the capacitance showed 32.5 pF at frequency range of 1 kHz and about 32.4 pF at the range of 200 kHz for 0 V. In addition, the rising time of output signal was as fast response as 20.92 ns for 10V. For the optical properties, the best spectrum sensitivity was 0.57 A/W for 890 nm, while it was relatively excellent value of 0.37 A/W for 1,000 nm. Over all, there were good spectrum sensitivity for this diode over the range of 870 ~ 920 nm.

• Journal of Science and Technology Studies
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• v.19 no.3
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• pp.1-49
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• 2019

First proposed by Paul Crutzen and Eugene Stoermer in 2000, the concept of the Anthropocene has had staggering repercussions in a variety of disciplines. In response to the Anthropocene narrative as a problematization of the eco-ontological emergency that humanity is confronted with in the 21st-century, I will deal with the following theoretical themes in this article. Firstly, I will analyze the central agendas underlying the Anthropocene discourse: the expansion of human agency into the planetary level and the possibility of unprecedented catastrophes in the near future. Secondly, I will propose to address the Anthropocene discourse as problem-assemblage. Thirdly, I will examine Clive Himilton and Dipesh Chakrabarty's theses in order to understand the shock that was brought to bear on the humanities and social sciences by the Anthropocene narrative. Fourthly, I will reinterpret the allegory of the angel appearing in Benjamin's Theses on the Philosophy of History to explore new possibilities of transformative becoming of the subjectivity, focusing on the concept of patiency. Finally, I will present the concept of reflexive catastrophism.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3015-3024
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• 2018

This study investigates the recent asymmetric effect of news on stock return volatility in Asian five stock markets - Japan, Korea, Singapore, Taiwan, and Malaysia - since 2000. This study uses the GJR-M model which shows a different effect of a good and bad news on volatility. Empirical results show that the unexpected negative return has a more crucial effect on stock return volatility than the unexpected positive one does in all five stock markets. This implies that the bad news of the stock markets gives a more remarkable effect on volatility than good news does. This study finds that it is very important for market participants and regulation practitioners to distinguish between positive and negative return shocks in the stock markets since bad news might have a larger impacts on volatility than good news.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.63-73
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• 2010

Malicious bot programs, the source of distributed denial of service attack, are widespread and the number of PCs which were infected by malicious bot program are increasing geometrically thesedays. The continuous distributed denial of service attacks are happened constantly through these bot PCs and some financial incident cases have found lately. Therefore researches to response distributed denial of service attack are necessary so we propose an effective feature generation method for distributed denial of service attack detection using entropy. In this paper, we apply our method to both the DARPA 2000 datasets and also the distributed denial of service attack datasets that we composed and generated ourself in general university. And then we evaluate how the proposed method is useful through classification using bayesian network classifier.

• Korea Trade Review
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• v.42 no.6
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• pp.131-154
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• 2017

In international trade, transportation generally has the largest and direct impact on freight costs. However, it is also sensitive to external factors such as global economic conditions, global trade volume and exchange rate. Therefore, it is necessary to examine the relationship and influence of international trade in terms of external factors that affect the change of imports and exports by marine and air transportation through empirical analysis. In particular, the analysis of the impact of these external factors on marine and air transportation is an important topic when recent exchange rate changes are significant, and it is also necessary to analyze what transportation means are more sensitive to exchange rate changes. In this study, we use the Vector Error Correction Model to analyze the dynamic effects of changes in exchange rate and domestic and international economic conditions on marine and air transportation from January 2000 to March 2017. Respectively. Alos, Impulse response function and variance decomposition were examined.

• Journal of Forest and Environmental Science
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• v.40 no.2
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• pp.99-110
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• 2024

According to the REDD+ program, it is necessary to monitor, quantify, and report forest conditions in protected land areas. The objectives of this work were to quantify the average monthly aerial net primary productivity (ANPP_MONTH) of semi-arid Chaco Forest at Copo National Park (CNP), Santiago del Estero, Argentina, during the period 2000-2023, as well as its spatial distribution and relationship, and its use efficiency (RUE) of average monthly rainfall (AMR). The ANPP_MONTH model accounted for 90% of the seasonal variability from October to May, the average seasonal ANPP_MONTH was 145 tons of dry matter per hectare (t dm/ha), being the maximum in January with 192 t dm/ha and the minimum in May with 91 t dm/ha. The surface area covered by ANPP_MONTH exhibited a consistent positive trend from October to May (t test=15.65, p<0.01). Strong and significant direct relationships were found between ANPP_MONTH and AMRs, linear models explaining 90% and 96% of the variability, respectively. The results obtained become reference values for assessing the capacity of the forest systems to stock carbon for global warming mitigation and for monitoring and controlling their response to extreme climatic adversities. The average ANPP_MONTH reduces uncertainty when defining the thresholds to monitor and quantify ANPP and forest area, thus facilitating the detection of negative changes in land use in CNP. Such results evidence the National Parks Administration's high effectiveness for the maintenance of protected area and for the high ANPP of the FCHS of CNP in the period 2000-2023.

• The Korean Journal of Pesticide Science
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• v.14 no.2
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• pp.79-85
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• 2010

This study was investigated to review the potentials of irritation and skin sensitization of active ingredients and end-use products of pesticides for pesticide registration, prediction of irritation and sensitization, and data requirements for other purposes. Pesticide irritation and sensitization referred to the Pesticide Manual(14th edition), while toxicity was evaluated based on the data submitted by the pesticide registrant. Totally 148 active ingredients and 149 end-use products were analyzed to compare the positive response, formulation type, and correlation between active ingredients and products. Among active ingredients, ratio of positive response to skin irritation, eye irritation, and skin sensitization were 18.8, 47.0 and 20.6% respectively. While, positive response to skin irritation, eye irritation, and skin sensitization of the products were 14.9, 38.9 and 23.6%, respectively. Emulsifiable concentrate showed the highest positive response among formulation types showing skin irritation 31.3%, eye irritation 81.3%, and skin sensitization 31.3%. On the other hand granule type showed the lowest response with skin 4.8, eye 14.3 and sensitization 14.8%. There was no correlation by active ingredient content on irritation and sensitization of products. However, both active ingredients and products showed same positive response were skin 73.1%, skin sensitization 66.2%, and eye irritation 44.7%. By the these results, correlation between technical grade of active ingredients and end-use products would be use for pesticide management at the screening stage, especially skin irritation and skin sensitization.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.157-165
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• 2000

A small hydraulic winch system with an automatic tension control unit was designed to improve the work efficiency of coastal small vessels and the dynamic response characteristics of the winch system operated in the open loop condition was investigated. The inlet and the outlet pressures in hydraulic motor, the torque and the rotating speed of winch drum were measured as a function of time, and the behaviour in autotension mode for stepped load changes was analyzed. The results obtained are summarized as follows : 1. The developed winch system for coastal small vessels will result in better fishing with improved efficiency and lower manpower consumption by remote control of winch system. 2. The rotating delay times of winch drum for on/off operations of solenoid valve were 0.09 see at CW mode and 0.04 sec at CCW mode, respectively. After the solenoid valve was controlled, response characteristics were unstable slightly but showed good tracking behaviour over short time. 3. The driving torque of winch system in autotension mode was kept almost constant of 55.9 kgf·m, and 11.1 then the rotating speed of winch drum was kept almost constant of 5.1 rpm in the larger torque than 55.9 kgf·m and 11.1 rpm in the lower torque than that. 4. The 5% settling times in the transient response characteristics of autotension mode under rapid increasing and decreasing conditions of load were 0.12 sec and 0.2 sec, respectively, and then the rotating speeds were 11 rpm and 5.3 rpm, respectively. 5. The tracking behaviour of torque and rotating speed by remote control operation were stable within 0.23 sec at CW mode and 0.37 sec at CCW mode, respectively.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.4
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• pp.276-284
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• 2000

The acoustic emission (AE) behavior of reinforced concrete beams tested under flexural loading was investigated to characterize and identify the source of damage. This research was aimed at identifying the characteristic AE response associated with micro-crack development, localized crack propagation, corrosion, and debonding of the reinforcing steel. Concrete beams were prepared to isolate the damage mechanisms by using plain, notched-plain, reinforced, and corroded-reinforced specimens. The beams were tested using four-point cyclic step-loading. The AE response was analyzed to obtain key parameters such as the time history of AE events, the total number and rate of AE events, and the characteristic features of the waveform. Initial analysis of the AE signal has shown that a clear difference in the AE response is observed depending on the source of the damage. The Felicity ratio exhibited a correlation with the overall damage level, while the number of AE events during unloading can be an effective criterion to estimate the level of corrosion distress in reinforced concrete structures. Consequently, AE measurement characterization appears to provide a promising approach for estimating the level of deterioration in reinforced concrete structure.

• The Journal of Pediatrics of Korean Medicine
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• v.14 no.1
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• pp.9-38
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• 2000

It has been widely said in Korea that early administrations of Cervi cornu parvum (deer antler) to febrile infants affect brain functions. Traditional Oriental Medicine states that the head is easily affected by fever and only an excess of heat causes headaches. Traditional Oriental Medicine also states that Cervi cornu parvum cannot be used in febrile conditions. With the aim of investigating different febrile response to LPS, experiments using intravenous injection of LPS have been carried out on Cervi comu parvum(CCP) and Soahbohyul - tang combined with Cervi comu parvum(SB-CCP) administered rabbits. Experiments were also conducted to evaluate the effects of early administration of CCP on learning and memory in 3 week old rats with LPS fever. These were evaluated by using the Morris water maze and the radial arm maze. Changes in body weight were also observed during this period. The results of these experiments are as follows. 1. In the experiments with febrile rabbits, the CCP and SB-CCP administered group showed statistically significant reductions of fever (p<0.05). 2. In the experiments with febrile rabbits, CCP and SB-CCP administered rabbits resulted in the tendency of lower body temperatures and shorter fever periods than the control group. 3. There were no differences of mean body weight and fever patterns among the 4 groups in the experiments on young rats with LPS fever. 4. There was no statistical difference of mean response latencies among the rats in Group I (DDW administered), GroupIII (CCP administered), and groupIV (SB-CCP administered) in the Morris water maze. However, Group Ⅱ (the scopolamine administered group) showed delayed latencies on the second day of the first session (p<0.05), and the second and third day of the second session (p< 0.05). 5. There were no statistical differences of mean response latencies among the rats in Group I, III and Ⅳ in the radial arm maze, but Group Ⅱ showed delayed latencies on the first and third day of the first session (p<0.05). 6. There was no influence from the administration of CCP and SB-CCP on the general behavior of the rats in Irwin´s test. These results suggest that Cervi cornu parvum and Soahbohyul - tang combined with Cervi comu parvum have anti-pyretic actions on LPS fever. The results also suggest that these drugs have no influence on learning and memory in young rats with LPS fever in the Morris water maze and the radial arm maze.