Since the beginning of the history of the Korean people, there have been numerous foreign invasions, but each time, our ancestors have overcome national difficulties with the will of the hot country and extraordinary fighting spirit. There are countless heroes of the country who have displayed outstanding leadership in every national crisis, but no one can dispute the fact that Yi Sun-shin is the greatest hero, hero, loyalist, and martyr. Yi Sun-shin was the best war hero in Korean history, and when the country and its rivals were on the verge of collapse due to unprecedented disasters such as the Imjin War and Jeongyu Jae-ran, he commanded the Joseon Navy and won consecutive battles with his beliefs and extraordinary strategies. He was born as the son of a poor scholar and was a great teacher of the people who consistently maintained loyalty, humanity, and patriotism despite all kinds of hardships during his short life of 54 years. "It is hard for the British to admit that Admiral Yi Sun-shin of Joseon is an excellent commander comparable to that of Horatio Nelson, but it is undeniable that Yi Sun-shin is the best admiral in the East," said Maj. G.A. Billard, who was the principal of the Royal Naval Academy. Dr. Ray Huang, a Chinese-American historian and professor at Washington State University in the U.S., praised Yi Sun-shin as one of the three greatest war heroes in Oriental history, Chen Hundao of the Vietnamese Dai Biei Dynasty, and Wen Sung-hwan of the Ming Dynasty. In light of the situation in and out of the country today, especially the political and economic crisis that is once again missing, Lee Sun-shin is reminded of the fact that he was a CEO with extraordinary leadership in addition to the known master of saving the country. In order to survive infinite competition with powerful countries in the face of a new turbulent era of the 21st century, we will have to find the wisdom of overcoming the national crisis through the leadership of Seongwoong Lee Soon-shin, who was greater than any great man in East and West. ◆ The turtle ship, which was active during the Japanese Invasion of Korea in 1592, first emphasized the importance of military ships in preparation for the Japanese Invasion of Korea in 1592. Fortunately, among his subordinates was a military officer named Na Dae-yong, who had a natural talent for Joseon art. Na Dae-yong received the full trust of Yi Sun-sin and devoted himself only to building the turtle ship. Na Dae-yong was born in 1556 and passed the military examination at the age of 26, and joined Yi Sun-sin's barracks with Au Chi-yong at the age of 36 before the Japanese Invasion of Korea in 1592. Following the construction of the Turtle Ship, he participated in various maritime battles and established many majors, and after the Japanese Invasion of Korea in 1592, he created a new warship, Changseon, Haeju, a speedboat, and served as a governor of Gyeonggi-do during the reign of Gwanghae-gun and died at the age of 57. The turtle ship was almost in the final stage just before the Japanese Invasion of Korea in 1592, and Yi Sun-sin reported on its appearance and performance through Janggye after winning the Battle of Dangpo. "Shin built a turtle ship separately because he was worried about the invasion of Japanese pirates early on." The front is made of a dragon head, attached to it, fired cannons with its gills, and iron nails are placed on the back, and you can see from the inside, but you can't see from the inside. Although it is supposed to penetrate hundreds of enemy ships and fire cannons.' There is no data to appeal whether it was the same battleship, but the turtle ship was already in the reign of King Taejong, which appears in the Annals of the Joseon Dynasty. In other words, there is a record that in 1413, a mock battle between Gwiseon and Waeseon took place in the Imjingang River, and this turtle ship disappeared before long as the Japanese pirates became less aggressive. According to the records that the Turtle Ship has existed before, it cannot be said that it was invented by Yi Sun-shin or Na Dae-yong, but it was never made under the direction of the 조정 adjustment. Also, even before he took office, he was not in Jeolla Jwasuyeong or other naval camps. However, he would have reported in advance to his immediate superior, the governor of Jeolla-do, and obtained permission. Otherwise, if such a formidable battleship had been built on its own, it would surely have been suspected of its ancestors. The records of Yi Sun-shin's Haengrok describe the appearance of the turtle ship in this way. The size is the same as the Panokseon, and the top is covered with a board. There was a narrow cross-shaped road on the board so that people could pass, and all other blades and awls were inserted so that there was no place to put their feet on all sides. A dragon head was attached to the front to make the mouth a gun hole, and a turtle's tail was attached to the back to make a gun hole under it. In addition, six gun holes were made on the left and right sides, and the entire shape was generally the same as a turtle, so the name was called Geobukseon. When he met and fought against the enemy, he covered the awl and blade with a giant and became a vanguard. The enemy was stabbed by blades and awls and shot from the left and right to attack, and the ship was always victorious in the big and small battles after World War II, as the enemy ship ran in and out of the sea. We were only two days before the Japanese landed in Busan. There are two types of data on the turtle ship: the so-called "Control Yeongwisundo" and "Jeollajwa Suyeong Gwisundo," which were compiled in 1795, 200 years after Yi Sun-sin's death, so the accuracy of the data cannot be guaranteed. The salvage of the turtle ship continues steadily in the southern coast, but not a single relic worth seeing as the remains of the turtle ship has been recovered. There is no exact data left on the number of turtle ships, so we have to infer that Yi Sun-sin's Janggye said, "The turtle ship is not less than 125 masters and soldiers..." and "There is no way to supplement 130 soldiers to one ship." Based on these records, the characteristics of the turtle ship show that it was a special warship with the function of the first charge ship, an invincible combat ship made much stronger than the second general battleship, a horror ship with superior firepower, and a defenselessness. On the other hand, there are several theories about the number of turtle ships built by Yi Sun-sin during the Japanese Invasion of Korea in 1592, but there is a consensus that it is generally three ships. ◆ Gunpowder weapons far superior to the Japanese military. Then, how much power did the Joseon Navy have at the time of the Japanese Invasion of Korea in 1592. According to the remaining records, there were generally two turtle ships, 177 Panok ships, 119 narrow ships, 1,800 ships installed here, and a total of 49,800 troops. At that time, there were about 12,000 soldiers on 73 military ships, including 44 Panokseon and 29 Hyeopseon in Gyeongsangwoo Suyeong under Won Gyun, and about 7,000 soldiers on 41 military ships, including 24 Panokseon and 15 Hyeopseon. In addition, although there was no naval battle, it is estimated that there were 40 Panokseon ships in Chungcheong-do, and there were also investigations in Gyeonggi-do, so there must have been battleships such as Panokseon. However, in the early days of the war, Gyeongsang Udo and Gyeongsang Jwa Do Su-gun destroyed and destroyed their own warships, leaving only four Panokseon and two narrow ships even before fighting with the Japanese, so it was regrettable that the power of the Joseon Navy was halved. Along with the construction of warships, including turtle ships, Yi Sun-sin's efforts were to manufacture and stockpile various artillery and gunpowder for use in naval battles. In particular, he made great efforts to prepare various gunpowder such as Cheonja Chongtong, Jija Chongtong, Hyeonja Chongtong, and Hwangja Chongtong, which were not used as the main weapon in naval battles at the time, as well as Daejanggunjeon, Hwajeon, and Cheolhwan. In the early days of the Japanese Invasion of Korea in 1592, when the Army, which was in a hurry, failed to defeat the Japanese new weapons with its bow and spear, and Shin Rip, known as the master of the time, was defeated in the Battle of Tangeum, and destroyed through Kaesong and Pyongyang. This is because the power of the fleet armed with the Panokseon and the strongest assault ship, the Turtle Ship, and its superior performance of gunpowder and gunpowder were powerful according to his excellent strategic tactics. Then, this time, we will look at gunpowder and other gunpowder. Until then, the level of iron and gunpowder weapons in Joseon was ahead of Europe. The cannon used in Europe was rolled up in a round iron pipe and tightened with an iron frame, and the shell was also a gun cast from Joseon's Daepot iron, and the shell was also an iron ring made of iron. In addition, European cannons often exploded before the cannon was fired due to a misalignment of gunpowder. Korea's gunpowder weapons were developed by Choi Moo-sun in the late Goryeo Dynasty and developed and mass-produced in earnest during the reign of King Sejong of the Joseon Dynasty, and were deployed to military fortresses nationwide. In 1435, 1,650 artillery pieces were produced, 900 in Pyeongan-do and 750 in Hamgyeong-do, and in 1445, 10,000 in Hyeonja Chongtong were deployed throughout Joseon. King Munjong, who succeeded King Sejong, worked hard to develop cargo trucks and deployed 367 cargo trucks to 32 military points, including Hansung, Pyeongan, Hamgyeong, and Jeolla and Gyeongsang provinces. It is the same as today's cannon that Cheonja Chongtong or Jija Chongtong are. The gun was cast in copper or bronze iron, measuring 120 to 200 centimeters in length, 18 to 40 centimeters in diameter, and weighing 78 to 725 kilograms. The gunman fired iron rings, but it mainly fired Daejanggunjeon, Chajeon, and Piryeongjeon, which are called super-large arrows. Daejanggunjeon Hall is a wooden stick with a length of 36cm, a diameter of 15cm, and a weight of 30kg, with an iron head of about 21cm at the end and three 75cm iron feathers on its body. When this super-large arrow was fired with a loud gunfire that rang the sky and earth and stuck into the enemy ship, the enemy was in chaos, exerting the terrifying power of pounding or sinking a large hole in the water-hot stomach. Janggunjeon Hall and Chajeon Hall were the same structure and only small in size, and Piryeongjeon Hall was made of leather instead of metal. The range was about 1km when Daejanggunjeon was fired into the Cheonja Tongtong, and the iron ring was 4km, and 640m when Janggunjeon was fired into the Jija Chongtong, and 200 iron rings were fired. The reason why Joseon was defeated by the Japanese military's personalization of gunpowder, such as spear, bow, sickle, pickax, hoe, and bamboo spear, even though it had a superior gunpowder weapon in the early days of the Imjin War. This was due to the fact that he did not care about military threats during the peace process that lasted for about 200 years. Since it was a disaster caused by Seolma, it was a self-employment of no illusions. They did not care about military threats or national defense at all, and they fought with their heads to explode only in the struggle for the regime, so they became frogs in the well. Therefore, there was no budget allocation for national security. Therefore, until the Japanese Invasion of Korea in 1592, there were such excellent gunpowder weapons, but there was no room or will to mass-produce and deploy them. However, the Joseon government army was able to exert its power by Admiral Yi Sun-shin, who did not forget the power of gunpowder weapons. Yi Sun-sin was a jijang who really knew how to look forward. That's why economists in modern times refer to him as a great CEO. In order to strengthen his military armament in preparation for the upcoming war, Yi Sun-sin almost forgot to erode in the construction of warships and strengthening military training, as well as the manufacture of gunpowder and weapons. Admiral Yi Sun-shin made various artillery pieces such as Cheonja Chongtong, Jija Chongtong, Hyeonja Chongtong, and Hwangja Chongtong, as well as Janggunjeon, Jangpyeonjeon, Piryeongjeon, Hwajeon, and iron and etc. to be used for them. While Yi Sun-shin predicted such a future war and made efforts day and night to prepare for the war, the incompetent government's defense policy was at a loss. Shin Rip, who is even recognized as the best master of Joseon, said, "We should get rid of the navy and focus only on the land battle."There was a time when he posted an absurd plot. In response, Yi Sun-sin raised a general rule on the court and said, "There is nothing to follow the navy in preventing Japanese invaders from invading the sea. Therefore, neither the army nor the navy can be abandoned," he said, pointing out the injustice. Lee Soon-shin was not a government official who sat at the headquarters and gave orders and instructions only with his mouth just because he was the supreme commander. He shared the joys and sorrows of his men, and he was an excellent commander, who was constantly under his command, and who knew how to prepare for the coming enemy invasion by practicing martial arts in the archery field He was a strategist. Yi Sun-shin took the initiative in everything and set an example for soldiers. Just because you sit comfortably and give orders only with your mouth, you cannot gain the trust of the eldest son under your command. Nor could that have forced soldiers to fight with their lives in case of emergency. Yi Sun-shin knew all too well about it. That's why he felt the need to reinstate the soldiers' mental armament. However, Lee Soon-shin did not only treat his subordinates benevolently with infinite patience. He cherished and loved his subordinates with extraordinary affection, but he ruled strictly without forgiving any deviation that went beyond the limit. Yi Sun-sin was indeed a commander who was strict with the principle of punishment for Shin Sang. Yi Sun-shin made Odongdo Island, Yeosu-si, where Jeolla Jwasuyeong was located, trained the soldiers, built fountains everywhere to protect the Jwasuyeong, and made holes in large stones under the Suyeong Al Sea and laid chains together. In addition, Yi Sun-shin performed Manggwallye and watched public affairs on the first and fifteenth days of each month, and after finishing his official duties, he practiced archery to train himself and his generals in martial arts. These days, archery can be said to be a shooting drill, and Yi Sun-shin never neglected to practice archery just because he was a general and a busy official. Rather, he encouraged archery by walking to the table whenever he had a chance, and after the archery match, he shared alcohol with the generals and relieved fatigue. That was Lee Soon-shin's extraordinary and outstanding leadership. Yi Sun-shin trained his mind and body through a bow, not a sword, and human exchanges with his subordinates, and promoted unity. Hwang Won-gap's "Revival Yi Sun-shin" Eco Business 2004; Kim Jong-dae's "Shin" still has 12 warships. BookForce 2001, Choi Doo-seok's "Imjin Japanese Invasion" and Lee Soon-shin's 1999 works.