• Korean journal of applied entomology
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• v.31 no.3
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• pp.205-240
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• 1992

In reality, it is a green revolution of the entire agricultural matrix in Korea that integrated pest control plays an important role in the possible breakthrough in rice self-sufficiency. In paddy agroecosystem as man-modified environment, rice is newly established every year by transplantation under diverse water regimes which affect a microclimate. Standing water benefits rice by regulating the microclimate, but it favors the multiplication of certain pets through the amelioration of the microclimate. Further, the introduction of high yielding varieties with the changing of cultural practices results in changing occurrence pattern of certain pests. In general, japonica type varieties lack genes resistant to most of the important pests and insect-borne virus diseases, whereas indica type possesses more genes conferring varietal resistance. Thus, this differences among indica type, form the background of different approaches to pest management. The changes in rice cultivation such as double cropping, growing high-yielding varieties requiring heavy fertilization, earlier transplanting, intensvie-spacing transplanting, and intensive pesticide use as a consequence of the adoption of improves rice production technology, have intensified the pest problems rather than reduced them. The cultivation of resistant varieties are highly effective to the pest, their long term stability is threathened because of the development of new biotypes which can detroy these varieties. So far, three biotypes of N. lugens are reported in Korea. Since each resistant variety is expected to maintain several years the sequential release of another new variety with a different gene at intervals is practised as a gene rotation program. Another approach, breeding multilines that have more than two genes for resistance in a variety are successfully demonstrated. The average annual rice losses during the last 15 years of 1977-’91 are 9.3% due to insect pests without chemical control undertaken, wehreas there is a average 2.4% despite farmers’insecticide application at the same period. In other words, the average annual losses are prvented by 6.9% when chemical control is properly employed. However, the continuous use of a same group of insecticides is followed by the development of pest resistance. Resistant development of C. suppressalis, L. striatellus and N. cincticeps is observed to organophosphorous insecticides by the mid-1960s, and to carbamates by the early 1970s in various parts of the country. Thus, it is apparent that a scheduled chemical control for rice production systems becomes uneconomical and that a reduction in energy input without impairing the rice yield, is necessarily improved through the implementation of integrated pest management systems. Nationwide pest forecasting system conducted by the government organization is a unique network of investigation for purpose of making pest control timely in terms of economic thresholds. A wise plant protection is expected to establish pest management systems in appropriate integration of resistant varieties, biological agents, cultural practices and other measures in harmony with minimizing use of chemical applications as a last weapon relying on economic thresholds.

• Journal of the Korean Society of Costume
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• v.55 no.5 s.95
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• pp.108-119
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• 2005

The objective of the study is was investigate the condition of the battle dress uniform worn by male members of the Korean Police Special Weapons Attack Team(KP-SWAT), identify problems, and provide basic raw materials for developing improved design of BDU. For this purpose, the researcher conducted a questionnaire survey on 92 male members of SWAT (Special Weapon Attack Team) units in Seoul using a questionnaire developed through observation and interview. Also, the body sizes of male SWAT members were measured. According to the results of body size measurements, male SWAT members generally require uniforms with a target bust girth, armhole, biceps circumference, thigh and calf circumference, longer jacket length, sleeve length, and trouser length to the knee. According to the results of the questionnaire survey, they reported dissatisfaction with the fit. In addition, they said that the Pockets are positioned too low for convenient use. Many subjects reported that their trousers were too short because of the rubber rings at the bottom of the legs. In addition, many subjects requested the alteration of the inconveniences caused by the designs finished with velcro on the bottom collar of the upper uniform, the marks and ensigns of the upper uniform, the bottom of the upper and lower uniform, and several pockets. Furthermore, there were many complaints concerning how they had to wear their uniform. The most frequently worn out and the body parts most often injured in field training and operations, they were reported, on the upper uniform, as the elbow, collar, neck, armpit, shoulder, and sleeve hem in that order, and on the lower uniform, the knee, interior calf, waist (belt rings), buttocks (rear pockets), and the bottom of the trousers (ankle) in that order As for questions concerning priorities in the improvements of the operational uniform and preferred design, the subjects recommended improvement in safety (protectiveness), workability (motional flexibility), design (shape), fit (size), comfort, ease in terms of putting on and taking off, etc., and the majority preferred two-piece designs ($67.4\%$), followed by one-piece ($30.4\%$), or both ($2.2\%$).

• Journal of the Korea Concrete Institute
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• v.29 no.2
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• pp.169-177
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• 2017

Rather than causing damage from heat, blast, and radiation of a regular nuclear weapon, recently, it is predicted that North Korea has been inventing high altitude electromagnetic pulse (HEMP) missile in order to incapacitate electronic equipment. HEMP shielding facility is used for military purpose today. Despite the electromagnetic shielding effects from high quality compression plates, problems may include such as the possibility of electromagnetic influx resulting in the welding of the compression plates, and difficulties and high cost of construction. Therefore, in this study, a high electrical conducting material was added to the concrete experimental subject to ensure the shielding effect through electromagnetic waves to for the concrete structure, instead of building a shielding facility separately for the structure. Also, among the experimental subjects, 100 ${\mu}m$ of Iron-Aluminum alloy metal spraying coat was applied to two types with the highest shielding effect, and to two types with the lowest shielding effect. The result of the experiment indicates that experimental subjects added with a high electrical conductivity material did not meet the minimum shielding criteria of MIL-STD-118-125-1 standard, but all the experimental material applied to the metal spraying coating satisfied the minimum shielding criteria. In conclusion, it is considered that 100 µm of Iron-Aluminum alloy metal spraying coat contains high efficiency in the HEMP shielding.

• Journal of forensic and investigative science
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• v.1 no.2
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• pp.31-43
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• 2006

I searched the recent murder cases for other criminal methods of homicides the monthly statistics of the local police agencies of the whole country, I found that there are many criminal cases where knives were used. Based on this finding, I decided to conduct my survey about kitchen knives. The statistics indicated more than five hundread male and female adults were reported to have committed murders. Of the 500 people, 21 used a kitchen knife to commit murder. This study showed that when people have a conflict, the kitchen knife is as a tool that can be easily changed into a weapon. If the points of the knife is round, more homicides could be avoided. If regulations were established, as we have with dagger when producing, selling or purchasing, I would assume that the number of the crimes with knives will be remarkably diminished. It is our responsibility to create a bill concerning regulatory standards in understanding the dangers of kitchen knives. We must immediately participate in active publicity campaigns.

• Journal of the military operations research society of Korea
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• v.34 no.2
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• pp.163-174
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• 2008

The military is an organization where reliability and availability take much more importance than in any other organization. And, in line with a recent trend of putting emphasis on 'system readiness', not only functions but also availability of a weapon system has become one of achievement targets. In this regard, the military keeps spares for important facility and equipment, which is called as Maintenance Float (M/F), in order to enhance reliability and availability in case of an unforeseen event. The military has calculated yearly M/F requirements based on the number of equipment and utilization rate. However, this method of calculation has failed to meet the intended targets of reliability and availability due to lack of consideration on the characteristics of equipment malfunctions and maintenance unit's capability. In this research, we present an analysis model that can be used to determine an optimal M/F inventory level based on queuing and absorbed Markov chain theories. And, we applied the new analysis model to come out with an optimal volume of K-1 tank M/F for the OO division, which serves as counterattack military unit. In our view, this research is valuable because, while using more tractable methodology compared to previous research, we present a new analysis model that can describe decision making process on M/F level more satisfactorily.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.251-261
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• 2016

Recently, many weapon related quality issues have arisen in the armed forces, such as failures of K-21 Infantry Fighting Vehicles, K-9 self-propelled mounts, and grenade explosion during boot training. Since all of the issues are repetitive phenomena, we examined the defense quality management system and identified the possible solutions for it. Since the government quality assurance agency performs their quality assurance activity using the system evaluation technique, we first reviewed the regulations related to the defense quality management system. Then, we benchmarked some other advanced quality management systems. We suggested two types of defense quality management system, one for small (in terms of the amount of the contract) competitive contracts and the other for large private contracts. For the first one, we adopted the framework of MIL-I-45208 (Inspection System Requirement), while for the second one, we adopted the framework of NATO AQAP 2310 (Quality Management System Requirements for Aviation, Space and Defense Suppliers).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.535-545
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• 2019

The PBA of ship weapon system should be installed and operated under harsh environmental conditions and so it should be highly reliable to endure the mission profiles during its entire lifetime. In the case of PBA failure during operation, rapid maintenance is highly likely to be difficult due to problems such as supply of parts, which can have a devastating effect on the mission. In order to validate the reliability of PBA, a series of tests are performed with PBA samples, but they require time, testing facilities, samples, expenses and failure analysis if failed. The reliability of PBA is predicted on the basis of specifications such as MIL-HDBK-217F, but this specification does not take into account failure mechanisms for specific design details, environment and usage, interconnects and its characteristics that drive many failures of PBA in the field. Therefore, this study predicts the reliability of PBA using an RPA tool and proposes the RPA methodology as a validation process at the design stage. With RPA, it is now possible to achieve design validation including inherent failure mechanism, identification of weakest link, alternative design options, and test plan development.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.102-109
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• 2019

This paper describes the design of the circuit card assembly to eliminate the communication error on a servo control unit installed in the automated resupply vehicle K56. K56 is a weapon system that automates the supply and loading of ammunition on the K-55A1 self-propelled artillery. As the core item responsible for ammunition movement control, the servo control unit is required to have good communication stability and reliability, but the conventional unit has recognized a problem that communication error intermittently occurs, resulting in an emergency stop phenomenon. We analyzed the communication signal of the servo control unit and identified the failure cause of the circuit card assembly to solve this problem. In addition, the signal interference in data/address line of the circuit card assembly was confirmed through analysis of the failure cause, and redesigned to avoid the interference, such as adjustment of the distance between communication lines and position change. Finally, the proposed cause analysis and redesign were verified through the component of servo control unit and attachment test on K56. We expected these study results to be used as reference for the design of other similar items.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.444-455
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• 2019

The purpose of this research was to analyze technological trends of 「Military Small Giant Venture Tech-Fi Net」 from Defense Technology Information Service via social network analysis. 「Military Small Giant Venture Tech-Fi Net」, which was constituted for their fine technology for application to the military field, registered 847 technologies of 388 companies. In this research, we analyzed 847 technologies for the relations between "Military System" and "Military Technology Category" via centrality measurement, one of the social network analysis methods. The results indicate that the major technologies of domestic military small giant venture companies were "Sensor" and "ICT" for "C4I System" and "Surveillance and Reconnaissance System" and "Platform/Structure" for "Land System", "Aeronautical System" and "Naval Sea System". In contrast, we recognized inadequate technologies, such as "Propellant" and "Material" for "Missile and Ammunition system" and "Sensor" and "ICT" for "Defense System", We hope that our results and method will be conducive to the technological development of Small Giant Venture companies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.437-445
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• 2020

Smoke grenades are the primary means of protection used by tanks to disrupt enemy detection systems. Such smoke grenades are a critical factor that determines the survival of tanks in the engagement of ground weapon systems, but it can only be used once. Owing to its destructive property, the performance and safety of the smoke grenade cannot be confirmed prior to use. Therefore, the reliability of smoke grenades can be evaluated through various tests during the storage period. This paper presents the results of estimating the reliability and shelf life of IR screening smoke grenade launchers based on the result of the Ammunition Stockpile Reliability Program conducted in 2019. Among the smoke grenade launcher lots currently stored, 16 lots and samples were selected for each year of manufacture and tested. The reliability and shelf life were estimated by examining the number of defects and the change in quality characteristics of each test item. The results of this study can be used to assess the reliability of the smoke grenade launchers and to improve the quality of manufacturing sites.