• Journal of Veterinary Clinics
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• v.3 no.1
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• pp.277-298
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• 1986

This paper reviews the mechanisms effecting host defense in the mammary gland and assesses their possible in preventing of bovine mastitis. The streak canal is the first line of defense against invading mastitis pathogens, providing a physical barrier and antibacterial substances. The milk leukocytes are a second defense line by ingesting pathogens breached the streak canal by multiplication, physical passage, and propulsion during milking. Leukocytosis in milk and enhancement of the phagocytic defense machanisms of the udder were accomplished by inserting intramammary devices. Milk antibodies serum derived and synthesized in mamma tissue aggregate and opsonise bacteria, agglutinate and neutralise toxins, and inhibit. binding of bacteria to epitherial surfaces. Vaccination generally has been unsuccessful because protection is not absolute, but immunization is useful in controlling specific pathogens. Immunostimulant to enhance locally the protective nature of antibody-producing plasma cells concentrated in internal teat end tissue may be effective in reducing the occurrence of infection, but ineffective in preventing intramammary infections.

• Strategy21
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• s.44
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• pp.142-176
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• 2018

So far, the main threat to South Korea was North Korea. That is why South Korea established a strategy based on the threat of North Korea and most of the budget on defense was used to deter North Korea. Even though the neighboring countries(China, Japan, and Russia) are growing as a real threat with abilities and intentions based on their powerful naval forces, South Korea has not yet been able to establish a strategy that regards neighboring countries as a threat. But the decades-old structural mechanism of the Korean security environment is undergoing a radical change on April 27, 2018, through the South-North summit and the Panmunjom Declaration. Under the changing security environment, South Korea was placed in a complicated dilemma that had to deal with threats of two axes(China), three axes(China, Japan), and four axes(Japan, Russia). If the one axis threat(North Korea) is dominated by land threats, the second, third and fourth axis threats are threats from the sea. This paper analyzed the maritime strategy of Korea within the framework of maritime-geopolitics, in other words recognition and expansion of the sphere of maritime. I have designed that the maritime defense space that we can deny from threats is divided into three lines of defense: 1 line (radius 3,000km), 2 lines (2,000km), and 3 lines (1,000km). The three defense zones of the three lines were defined as an active defense(1 line), defensive offense(2 line), active offense(3 line). The three defense zones of the three lines were defined as the sphere of core maritime, As a power to deny the sphere of core maritime, it was analyzed as a maneuvering unit, a nuclear-powered submarine, the establishment of missile strategy, and the fortification of islands station. The marine strategy of South Korea with these concepts and means was defined as 'Offensive Maritime Denial Strategy'.

• Strategy21
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• s.42
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• pp.83-113
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• 2017

After defeat in World War II, Japan's Peace Constitution committed the country to forego the acquisition of offensive military capabilities. However, in the midst of the post-cold war period, Japan began to change its security posture in line with the so-called 'normal state theory', which called for a more robust defense posture and expanded security activities. The second Abe administration promoted these security policies by issuing a National Security Strategy as well as a new National Defense Program Outline(NDPO) in 2013 and by establishing new security institutions such as the National Security Council. The Abe administration also adopted the new concept of a 'Unified Mobile Defense Force' in the 2013 which replaced the 'Dynamic Defense Force' as a new criteria for the Self-Defense Force's acquisition of military capabilities. In this new concept of military capabilities, the Ground Self-Defense Force is planning to replace existing divisions with mobile divisions and to form 'Amphibious Rapid Deployment Bridge' for the first time in 2018, which has long been taboo in Japan. Japan has experience a Marine Corps in the past. Likewise, an offensive changes in the military strategy can change the spectrum of strategy and 'Amphibious Rapid Deployment Bridge' plays a big role in this. Furthermore, Japan is increasing the Coast Guard's budget and capabilities in preparation for contingencies around the Senkaku islands (called the Diaoyu in Chinese). The South Korea navy should utilize Japan's changing security posture to deter immediate threat such as North Korea's military provocations and potential enemy threat such as China, Japan, Russia.

• Journal of Korean Medical classics
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• v.34 no.2
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• pp.127-168
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• 2021

Objectives : First, the time of publication of the writing Jinjeong(陳情), was identified with consideration of current affairs at the time in Hamgyeongdo. Second, the relevance between agricultural policies and military/defense policies were identified. Third, based on these findings, the phrase "洋醜之漁獵頻泊汊 港, 峩人之耕牧恒據沿䐉" was throughly examined within its historical context. Methods : First, the time of publication of the writing Jinjeong(陳情), was identified with consideration of current affairs at the time in Hamgyeongdo. Second, the relevance between agricultural policies and military/defense policies were identified. Third, based on these findings, the phrase "洋醜之漁獵頻泊汊 港, 峩人之耕牧恒據沿䐉" was throughly examined within its historical context. Results & Conclusions : 1. The Jinjeong(陳情) of the Dongmuyugo(東武遺稿) is a writing on crossing borders into the Maritime Province of Siberia, which was written between the end of September and December of 1870. 2. The phrase "洋醜之漁獵頻泊汊港" is related to the incident when a handover line was at anchor in the Unggi harbor three times in 1869. 3. "我人之耕牧恒據沿海" refers to the rumor spread in 1870 about Russia being an ideal country that practiced ideal politics, to the extent of cattle and horse being gifted to immigrants into the country.

• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.626-632
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• 2020

Radiation Portal Monitors (RPMs) are our primary border defense against nuclear smuggling, but are they still the best way to spend limited funds? The purpose of this research is to strategically compare RPM defense at the border with state-side mobile detectors. Limiting the problem to a comparison of two technologies, a decision-maker can prioritize how to best allocate resources, by reinforcing the border with stationary overt RPMs, or by investing in Mobile Radiation Detection Systems (MRDs) which are harder for an adversary to detect but may have other weaknesses. An abstract, symmetric network was studied to understand the impact of initial conditions on a network. An asymmetric network, loosely modeled on a state transportation system, is then examined for the technology that will maximally suppress the adversary's success rate. We conclude that MRDs, which have the advantage of discrete operation, outperform RPMs deployed to a border. We also conclude that MRDs maintain this strategic advantage if they operate with one-tenth the relative efficiency of their stationary counter-parts or better.

• Korean Journal of Heritage: History & Science
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• v.54 no.1
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• pp.260-279
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• 2021

The Goguryeo kingdom established a unique defense system centered on a series of mountain fortresses. However, modern-day studies on its defense system have tended to focus on how they were positioned and generally consist of little more than individual surveys or introductions to the relevant materials, leaving much to be desired. This study attempts to extend the scope of studies about fortresses dating back to the Goguryeo period, taking into account the limitations of the available materials. As such, this study reviews the defense system of Goguryeo during the Gungnaeseong Period (i.e., the period when Gungnaeseong was the capital of Goguryeo) using the GIS system, with the focus on fortresses that are thought to have been built in the area extending from the middle and upper reaches of the Amnok River to the mid-stream region of the Liohe River, based on the aforementioned studies. The results of the study are as follows. First, the major roads built during the Gungnaeseong Period were as stated in the foregoing studies to some extent. Researchers believed that during the middle period of the dynasty, a major road ran along the Suzihe, Fuer and Xinkai rivers before finally reaching Jian. The study found that fortified walls and fortress strongholds were built along this road. Second, there were seven fortresses between the middle and upper reaches of the Amnokgang River and the midstream region of the Liaohe River. A primary defense line was closely established between the strongholds and the nearby walls, with secondary and tertiary defense lines established more loosely and encompassing a much wider area. Third, regarding the defense system along the major roads, the Choejinbosanseong, Goisanseong and Cheolbaesanseong fortresses served as strongholds along the 60-kilometer-long primary defense line, with 80-kilometer-long secondary and tertiary defense lines set up behind it. The final 120-kilometer-long defense line of the capital was established along with the Onyeosanseong Fortress, while a stumbling block was set up close to the capital as a defense system, rather than building a fortified wall. To summarize, a primary defense system was established centered on a series of fortresses, with each stronghold maintaining a closely-knit defense system in connection with other nearby strongholds to repel invaders.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.327-332
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• 2006

In airborne gravimetry, there are two data streams. One is the specific force measured by an air/sea gravimeter or accelerometers, the other is kinematic acceleration measured by DGPS. And the difference of them provides the gravity disturbance information. To satisfy the requirement of most applications, an accuracy of 1mGal $(1mCal=10^{-5}m/s^{2})$ with a spatial resolution of 1km is the aim of current airborne gravimetry. There are two different methods to derive the kinematic acceleration. The generally used method is to differentiate the position twice, and the position can be calculated by commercial DGPS software. The main defect of this method is that integer ambiguities need to be fixed to get the precise position solution, but it's not a trivial thing for long base line. And to fix integer ambiguities, the noisier iono-free measurement is used. When differentiation is applied, noise is amplified and will influence the accuracy of acceleration. The other method is to get carrier phase acceleration by differentiate the carrier phase first, and then using the acceleration of GPS satellite to derive the vehicle acceleration. The main advantages include that fixing integer ambiguities is not needed anymore, position can be relaxed to about 10 meters, and smoother acceleration can be got since iono-free measurement is not needed. In some literatures, it's considered that the dynamic performance of the second method is inferior to that of the first. Through analysis, it is found that the performance degradation in dynamic environment results from the simplification of the GPS carrier phase observable model. And an iterative algorithm is presented to compensate the model error. Using a dynamic GPS data from an aeromagnetic survey, the importance of this compensation is showed at last.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.158.2-158
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• 2001

This paper introduces the design and implementation of a signal processing system for an airborne active homing radar system. This airborne active homing radar system uses the pulse Doppler radar of high PRF (Pulse Repetition Frequency) for computation of exact relative velocity of the target. This system carries out two operations mainly. The first is to transmit and receive microwave signal through the antenna. The second is to calculate the relative velocity of the target taking advantage of the Doppler frequency signal reflected from the target and detect the angle error between a target and an antenna LOS (Line Of Sight) to make the antenna direction coincident with the target. The signal processing system has a role of the latter.

• Fire Science and Engineering
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• v.33 no.6
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• pp.35-42
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• 2019

The aim of this study is to investigate the direction of improvement of safety experience education through the analysis of the evacuation time experiment. For the study, test subjects were divided into groups of similar body size and weight. The test subjects were directly experienced four evacuation devices, and the experience time was measured. As a result of the analysis of the total time from the installation of the evacuation device to the escape, the time was measured in the order of Descending Life Line-Tilt-Down Rescue Line-Vertical Escape Chute-air safety mat. In the case of evaluating the evacuation time using evacuation mechanisms, the evacuation time was measured in the order of air safety mat-Tilt-Tilt-Down Rescue Line-Descending Life Line-Vertical Escape Chute. In the first and second experiments of the Descending Life Line, time differences were observed. The escape time using the Descending Life Line was reduced in the second experiment than in the first experiment. As shown in this result, education through experience has shown that behavioral confidence and time can be managed. The conclusion of this study is that the goal of safety education is to minimize human life and property damage. Therefore, in order to bring this effect to more people, it is necessary to make efforts to keep self-safe through experiential education.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.3
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• pp.437-444
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• 2015

Satellite selection and exclusion techniques have been applied to the global navigation satellite system (GNSS) with the aim of achieving a balance between navigational performance and computational efficiency. Conventional approaches to satellite selection based on the best dilution of precision (DOP) are excessively computational and complicated. This paper proposes a new method that applies a geometric sensitivity index of individual GNSS satellites. The sensitivity index is derived using the inner product of the line of sight (LOS) vector of each satellite. First, the LOS vector is computed, which accounts for the geometry between the satellite and user positions. Second, the inner product of each pair of LOS vectors is calculated, which indicates the proximities of the satellites to one another. The proximity can be determined according to the sensitivity of each satellite. A post-processing test was conducted to verify the reliability of the proposed method. The proposed index and the results of a conventional approach that measures the dilution of precision (DOP) were compared. The test results demonstrate that the proposed index produces results that are within 96% of those of the conventional approach and reduces the computational burden. This index can be utilized to estimate the sensitivity of individual satellites, obtaining a navigation solution. Therefore, the proposed index applies to satellite selection and exclusion as well as to the sensitivity analyses of multiple GNSS applications.