• Strategy21
• /
• 통권32호
• /
• pp.36-70
• /
• 2013

Waegu(倭寇)'s invasion in the Late Goryeo(高麗) Dynasty was huge damage for Goryeo's local society. And It was shock that Goryeo government's basic foundation of rules. Invasion background of waegu for Kyeong-in-yeon(庚寅年, 1350) was Kyushyu(九州)'s political divide because of Nihon(日本) government's confusion. Waegu was huge damage for Goryeo's Jo-wun(漕運, the shipping system of grain paid as a tax) system. So, government started military response, but it was turn out a failure and had great damage. When execution of military operations failed, Goryeo government sent diplomatic delegation to request the prevent of waegu, but the invasion continued. Since waegu invasion, Goryeo was got nowhere with defence of waegu. So, some people demanded for a new understanding of the ocean defence in the government. Lee-Saek(李穡), Woo-Hyeonbo(禹玄寶), Lee-Hee(李禧) and Jung-Ji(鄭地) were representatives of a new understanding of the ocean defence. Their demands were received attention when all operations had been failed. Therefore, Goryeo government began to reorganization of the naval forces and set up a special committee of gunpowder manufacturing named Hwa-tong-do-gam(火筒都監). This administrative reform was achieved substantial results since then. In 1380, the naval battle at Jin-po(鎭浦) was a big event that first gunpowder attack the waegu. Since Jin-po, Goryeo's naval forces gain confidence. In 1389, Dae-ma-do(對馬島) was attacked by Park-Wi(朴葳). It was meant that Goryeo's naval forces had huge offense power. Goryeo's defence system was focused on a northern race before 14th century waegu's invasion. So they were neglected their ocean defence. But after military operation of waegu's invasion was failure, they focused on the ocean defence. A new understanding of the ocean defence was foundation of that. It means to us to a new understanding of the ocean defence. Now, East Asia has maritime disputes. And we have high exposure to potential threats. So, we have a new understanding of importance of the ocean defence. And we fight for 21th century's ocean threats as foundation of sense of national security.

• 박물관보존과학
• /
• 제30권
• /
• pp.101-126
• /
• 2023

조선시대 복전총통은 문헌 기록이 없고 비교적 근래 실물로 알려진 총통이다. 그간 상세하게 언급되지 못했던 복전총통 12점의 제원, 형태, 명문, 성분 등을 비교하여 복전총통의 구조와 재료적 특징을 검토하였다. 복전총통은 제원과 형태에 있어 일정한 규격을 가지고 있었고, 제원과 문헌자료를 비교하여 발사체의 수도 추정하였다. 모병부에는 총통 명칭과 함께 외곽선이 양각으로 새겨져 있는데, 명문 외곽선은 다른 총통에서 볼 수 없는 복전총통의 가장 큰 특징이기도 하다. 따라서 이를 토대로 제작 과정 속 시문 원리도 살펴보았다. 한편 복전총통의 재료는 구리와 주석이 주성분이며 주석의 함량은 6wt%였다. 기 조사된 조선 청동 화약 무기의 평균 성분과 매우 유사하며, 중세 유럽의 청동 화포(Gun-metal)와도 유사한 경향임을 확인하였다. 이와 같은 결과는 화약 무기에 필요한 재료적 특성을 고려한 결과로 총통 재료는 합금 비율에 따른 기능을 우선한다고 볼 수 있다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
• /
• pp.254-255
• /
• 2017

The aim of this study is to investigate the impact resistant performance of steel short fiber-reinforced cement based composites (SFRCCs) containing 1.0, 1.5, 2.0 and 3.0% volume fraction of steel short fibers subjected to high velocity impact of steel projectile (the diameter of 19.05mm and the mass of 28.13g). The gunpowder impact facility was used for impact tests, and the impact velocity was from about 350 to 700m/s. The specimens were damaged in various failure modes, which are penetration, scabbing, and perforation. Comparing with Plain specimen, SFRCCs have superior capacity on the scabbing limit, and slightly bulged in the back side under the impact velocity of 700m/s. In addition, the impact resistant performance of SFRCCs improved with increase of steel short fiber volume ratio. The fibers play an important role in controlling the local damage of SFRCCs.

• 한국소음진동공학회논문집
• /
• 제17권9호
• /
• pp.777-784
• /
• 2007

With the development of micro electronic circuits and optical equipment, the demand for developing smart munitions with the ability to autonomously search for and attack targets has increased. Since the electronic components within smart munitions are affected by high temperatures, pressure, and impulsive forces upon the combustion of gunpowder, stability and reliability need to be secured for them. Securing those stability and reliability requires soft recovery system which can decelerate smart munitions. A theoretical analysis of flow is performed for the secure recovery of bullets on the basis of Euler equation for compressible fluids. The inner pressure on a pressure tube, the speeds of bullets, and the deceleration of munitions are calculated theoretically. Theoretical results are compared with the data from the experiment with soft recovery system set up at the laboratory.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2014년도 추계학술대회 논문집
• /
• pp.48-53
• /
• 2014

Rocket, held using the CCA for the mission, a plurality of recording devices, and navigation equipment. In case of a projectile which is entered the water after fired into the air, after performing stages and fairing separated in flight to enter the underwater. It is caused by the explosion of gunpowder mainly, vibration phenomenon of a large transition is induced structurally very, also on entering the water, have a significant shock structurally separated. If shock is transmitted directly to the CCA through the body, it can be caused malfunction of payloads, resulting in failure of the mission of the projectile. In order to ensure the stability against shock, in this paper, Calculating a target resonacne frequency of the CCA, and verified through modal test and analysis. Maximum acceleration position of CCA is checked by SRS analysis. In addition, effectiveness of shock isolation system through shock analysis.

• 한국화재소방학회:학술대회논문집
• /
• 한국화재소방학회 2010년도 춘계학술논문발표회 논문집
• /
• pp.481-486
• /
• 2010

본 논문은 실내사격장 화재 원인에 대한 조사를 위하여 권총 사용에 따른 화약잔사 양에 대한 실측 및 발화특성에 관하여 연구하였다. 화약잔사 양의 실측은 1차로 사대 부분을 밀폐한 상태에서 실내사격장에 사용되는 권총과 동일한 구경 0.38인치 권총 및 구경 9mm 권총을 5발 발사하여 총구 및 약실로 분출되는 화약잔사의 양을 측정하였으며, 2차로 사대 개방 후, 구경 0.38인치 권총을 100발 발사하는 경우, 사대 바닥면에 떨어지는 화약잔사의 양을 측정하였다. 화약잔사에 대한 발화특성은 충격 감도, 정전기 감도, 마찰 감도 및 발화점 시험을 실시하였으며, 비교 평가에는 권총에 일반적으로 사용되는 사용전의 화약(ball powder)을 이용하여 화약잔사와 동일한 시험을 실시하였다. 실험결과 충격감도 및 마찰강도는 화약잔사에서 다소 높게 측정되었으며, 발화점 시험에서는 화약잔사가 비교대상인 사용전의 화약에 비해 낮은 온도에서 발화되는 특성을 나타내었다.

• 한국군사과학기술학회지
• /
• 제22권6호
• /
• pp.832-840
• /
• 2019

Recently, pollution from gunpowder due to shell shootings at military drilling sites has raised various environmental concerns. The purpose of this study is to predict the contamination level of RDX in the soil area of the firing range zone near Anwol river watershed, the study site, and the intake area, Anwol river and Imjin river, as a function of time and space. In this study, a multimedia model was developed to predict the variation of RDX contamination by rainfall. The range of the medium was limited to soil, water, and sediment, and excluded the atmosphere, taking into account the physical and chemical properties of RDX with low vapor pressure and low Henry's constant. The pollutant levels of the waters of compartments, including the last section of the Imjin River affecting the water intake, was compared with the environmental standard for RDX.

• 소성∙가공
• /
• 제30권1호
• /
• pp.16-21
• /
• 2021

A new concept of ammunition without the use of explosive gunpowder has been recently studied, which achieves performance equal to or higher than that of high explosives. Frangible Armor Piercing (FAP) is one of the concepts, which utilizes a tungsten alloy penetrator specialized for fragmentation. To investigate the fracture behavior of the tungsten alloy penetrator, Taylor impact tests were conducted at various impact velocities. Additionally, finite element analysis was performed to predict the fracture behavior of the tungsten alloy. Compression tests were also carried out at six strain rates for dynamic material properties and the dynamic hardening behavior was successfully predicted with the Lim-Huh model. Finally, the Mohr-Coulomb fracture model based on the mean stress was adopted to predict impact failure in Taylor impact simulation. The analysis predicts the deformation and fracture behaviors of the tungsten alloy successfully.

• 산업경영시스템학회지
• /
• 제37권3호
• /
• pp.36-42
• /
• 2014

Domestic 105mm HE (High Explosive) shell is composed of three parts that are Fuze, Projectile and Propellants. Among three parts, propelling charge of propellants part consists of single base propellants. It has been known that the lifespan of single base propellants is affected by a storage period. These are because Nitrocellulose (NC) which is the main component of propelling gunpowder can be naturally decomposed to unstable substances similar with other nitric acid ester. Even though it cannot be prevented fundamentally from being disassembled, a decomposition product ($NO_2$, $NO_3$, and $HNO_3$) and tranquillizer DPA (Diphenylamine) having high reactivity are added into a propellant to restrain induction of automatic catalysis by a decomposition product. The decay rate of the tranquillizer is also affected by a production rate of the decomposition product of NC. Therefore, an accurate prediction of the Self-Life is required to ensure against risks such as explosion. Hereupon, this paper presents a new methodology to estimate the shelf-life of single base propellants using data of ASRP (Ammunition Stockpile Reliability Program) to domestic 105mm HE (propelling charge of propellants part). We selected four attributes that are inferred to have influence on distribution of the DPA amount in a propellant from the ASRP dataset through data mining processes. Then the selected attributes were used as independent variables in a regression analysis in order to estimate the shelf-life of single base propellants.

• 한국자동차공학회논문집
• /
• 제18권2호
• /
• pp.1-6
• /
• 2010

This study presents the practical design modification to improve the retracting performance of the pyro-typed high power pretensioner. 3 components of the pretensioner are redesigned and the usefulness of the design modification is verified by the experiment. During the pretensioning process, the gas blast generated from the gunpowder is transferred to the rack-pinion gear through the manifold. The rack-pinion gear is connected with the spool where the webbing is rolled up. According to the rotation of the pinion, the spool is turned and the webbing is winded. To help the gas blast flow well, the shape of the inner cross section of the manifold is changed. The spur gear design program is developed and used to find the best combination of the rack-pinion gear pair to increase the power transmission efficiency. The pinion guide is installed on the spool to prevent the vibration of the pinion. As a result of the experiment, the amount of the web retraction length is increased when every single design modification is applied. Therefore, the retracting performance of the pretensioner is considered to be improved if the presented design modifications are applied.