자동변속기 스러스트 베어링 동력 손실에 대한 유성기어 세트 설계의 헬릭스 방향과 헬릭스 각의 영향에 관한 연구

권현식 한국정밀공학회 2024 한국정밀공학회지 Vol.41 No.6

Automatic transmissions, which have the advantages of compact structure and smooth shifting, are installed in variousvehicles with engines and hybrid power sources. Research and development are continuously being conducted to improvepower and fuel efficiency. In this study, the influence of helix direction and helix angle of the planetary gear set on thrustbearingpower loss in an automatic transmission was analyzed. A sample automatic transmission model was constructed toanalyze the axial load and bearing relative rotation speed, which are the main factors in thrust-bearing power loss. Therelative rotation speed of the bearing was analyzed using the sample model, and the thrust-bearing load in the axialdirection was analyzed according to the helix direction of the planetary gear set constituting the model and the helix angleof the planetary gear set. The power loss occurring in thrust-bearing was derived using the analysis results of relativerotational speed and load, and the influence of the helix direction and helix angle of the planetary gear set was analyzed.

유성기어 세트의 피니언 기어 개수와 기어 치 폭 변화에 따른 기어 성능을 고려한 설계 연구

권현식 대한기계학회 2023 大韓機械學會論文集A Vol.47 No.12

The design of a planetary gear set, a key power transmission component in automatic transmission systems, mandates crucial performance analysis and trade-offs considering torque and design space. This study investigates the design of a single-planet planetary gear set, considering the transmission torque and packaging space in the development process of an automatic transmission system. Specifically, it explores the gear performance in terms of contact and bending strength by varying the number of planet gears meshing with the sun and ring gears, and tooth width of gears. To this end, design configurations of simple planetary gear sets, obtained by varying the number of pinion gears and tooth width, were generated and analyzed in terms of gear performances and gear width.

철도테러 예방을 위한 철도경찰 보안검색 강화 방안 연구

권현식 한국경호경비학회 2016 시큐리티연구 Vol.- No.49

유럽 등 세계 곳곳에서 이슬람 무장단체(IS)나 자생적 테러 및 국제 테러조직이 다양한 방법으로 철도교통시설에서 폭발물 테러를 발생시켜 “테러와의 전쟁”을 벌이고 있다. 우리나라가 미국의 중동지역에서의 전쟁에 협력하는데 대해 이슬람권 국가들이 반한 감정을 갖고 있고, 이슬람 무장단체(IS)는 2015.9.9 이후 우리나라를 4번이나 테러 대상국 으로 지목했다. 또한 북한은 핵 실험, 미사일 발사 실험으로 국제사회에서 고립 당하고 남?북한 간 긴장을 고조시키며 우리의 중요인사 및 시설에 대한 테러 위협을 하고 있다. 이와 같은 테러가 철도교통시설에서 발생하는 것을 예방 및 차단하지 못할 경우 많은 인명 및 재산피해, 사회혼란, 국?내외적으로 테러 대응 정책실패에 대한 정부의 신뢰 하 락으로 관광객 감소, 외국의 투자기피, 자본이탈 등 국가적 위기 상황이 발생할 수도 있을 것으로 예상 된다. 본 연구에서는 철도경찰의 철도보안검색 등의 업무를 바탕으로 국민보호와 공공의 안전 을 위해 철도보안검색 강화를 위한 정책적 대응 방안을 제안하고자 함에 목적이 있다. 그 방안으로 첫째, 철도경찰의 인력증원 및 일반경찰과 업무 관할권 조정 둘째, 철도 보안검색의 단계적 확대 셋째, 철도의 중요시설 보안시스템 강화 넷째, 철도안전법 보완 다섯째, 동남아 등 각국의 불법체류자 단속 강화 여섯째, 보안검색요원의 인권침해 예방과 전문화대책 일곱째, 보안검색 및 테러예방 홍보와 테러 발생 시 신속한 대응을 위한 관련 기관들의 선제적 주기적 협력 방안 등이 필요하다.

항공테러 대비 공항운영자 및 경찰의 역량강화 방안 연구 - 항공 보안검색을 중심으로 -

권현식 원광대학교 경찰학연구소 2016 경찰학논총 Vol.11 No.3

세계적으로 국가간 이해관계, 종교간, 이해관계, 이념상의 충돌 등으로 인한 갈등과 대립이 계속되면서 불특정 다수인을 상대로 무차별적인 총격테러, 항공기 납치 테러, 폭발물 자폭 테러 등으로 많은 인명 및 재산 피해가 발생하고 있다. 각 나라에서는 이런 테러에 대비하기 위해 최선을 다하고 있으나 이를 막지 못해 테러의 위험성과 심각성이 계속 되고 있다. 현재 이슬람 급진 수니파 무장 테러 단체인 이슬람국가(Islam state ; IS)는 세계여러 곳에서 무차별적인 인명 살상 파괴 등 테러를 벌이면서 2015.9월 우리나라를“십자군 동맹국” 등으로 지칭하고 처음 테러 대상으로 지목한 후 4회에 걸쳐 테러위협 또는 테러를 선동 하고 있어 경계가 더욱 필요하다. 또한 북한은 과거에 우리의 항공기를 납치하거나 공중 폭파 하는 등 항공기 테러를 저지른 경험이 있고 UN등 국제 사회의 제지에도 불구하고 4차에 걸친 핵 실험및 중·단거리 탄도탄 미사일(Intercontinental Ballistic Missile)발사 시험을 계속하여국제 사회로부터 경제 제재 조치가 취해지자 공개적으로 청와대와 정부청사 폭파를위협하는 동영상을 게재하고 주요 인사 납치테러 및 중요시설 폭파와 항공기의 납치및 폭파 공항시설의 파괴 등으로 항공안전운항에 위해를 가하는 테러를 단독 또는국제 테러 조직과 직·간접적으로 연계하여 저지를 가능성이 높아지고 있어 테러로부터 안전한 나라가 아니다. 특히 2001.9.11 이슬람 무장 테러 단체 알카에다 조직이 4대의 민간 항공기를 납치하여 미국 뉴욕 맨해튼에 있는 쌍둥이 세계무역센터 빌딩 등 3곳에 충돌시켜 많은인명 및 재산 피해가 발생한 사건과 1958.2.26 북한이 우리 민간 항공기를 납치 및폭파한 4건의 사건과 해외에서의 민간 항공기 납치 및 폭파 사건 6건 모두 완벽 하지 못한 항공 보안검색의 실패가 원인이다. 국내·외적으로 항공 교통의 수요가 계속 확대 되면서 국민의 생명과 재산을 보호하고 국가 및 공공의 안전을 확보하기 위해 항공 보안검색에 대한 중요성이 커지고 있다. 항공기 테러발생을 예방하기 위한 지상 최대의 방법은 항공기 탑승객 및 항공화물에 대한 완벽한 보안검색이다. 따라서 공항운영자 및 항공운송사업자가 완벽한 보안검색을 하기 위해서는 민간경비업체의 보안검색요원(경비원)에 대한 처우개선 등 조직 관리 시스템 개선과 노후한 공항 보안장비의 교체, 특히 경찰은 공항운영자 및 항공운송사업자의 공항 보안검색 업무에 대한 보안검색요원(경비원)의 현장 보안검색에 대한 보완(보충)적 임무 강화, 보안검색요원(경비원)의 파업 등으로 인한 대체 인력 필요시 공항운영자와 함께즉시 대체 가능하도록 교육의 필요 및 항공 테러예방을 위한 관련 기관 협력 방안등 역량 강화 방안을 제시하였다. With continued conflicts of interest between countries, religions and ideologies, eavy casualties and property losses have resulted from various acts of terrorism, including indiscriminate shootings, aviation hijackings, and suicide bombings. Countries around the world have exerted efforts to combat terrorism, but terrorist activities still remain a serious threat. The Islamic State of Iraq and Syria (ISIS), a radical Sunni militant group, has carried out numerous terrorist attacks around the world. Korea was included in the list of countries labeled by ISIS the “crusader coalition” in September 2015 and has received a total of four terrorist threats. As such, there is a need for Korea to be on heightened alert against terrorism. Airport security breaches were one of the causes of the September 11 attacks by the Islamic terrorist group Al-Qaeda, in which four passenger airlines were hijacked and intentionally crashed into three buildings, including the Twin Towers of the World Trade Center in Manhattan, New York City. Security problems were also a central factor in the four hijackings of South Korean airliners by North Korea, including one in February 1958, and the six hijackings of civil airliners overseas. With the rising demand for air travel at home and abroad, airport security screening has grown increasingly important in the effort to protect citizens and air cargo, and to ensure public safety. The best solution to airline hijacking is complete, thorough security screening of passengers and cargo. For airport and airline operators to perform such screening, various approaches can be employed, such as the improvement and monitoring of organization management systems. Enhancements should include improvement of the working conditions of airport security screeners, replacement of worn-out security equipment, cooperation with the police in the security screening process by airport and airline operators, mandatory supervision of airport security screeners, and provision of adequate training for the workforce to enable immediate replacement of airport security screeners in the event of strikes.

형집행정지제도 운용상 문제점 및 개선방안 연구

권현식 한국교정학회 2007 矯正硏究 Vol.- No.36

A stay of sentencing is a ruling that allows the convicted, who has been sentenced to jail, confinement or detention, who has any humanitarian reasons, which confirm to any issues of the first clause of Article 470, similar with the first clause of article 471, under the criminal code procedure law pertaining to not giving any disadvantages except for purpose of an execution. But, commentators may question the fairness of rulings, because a prosecutor has decided to allow a stay of sentencing only forpublic characters, such as politicians, businessmen, or top ranking officials. Meanwhile, the suitor who gets a stay of sentencing may run away and some of them may commit a second offence, it is against to essential purpose of a stay of sentencing and the punishing authority may have a problem prosecuting. The chief constable observes, and reports, once a month, about people who have been released by a stay of sentencing, following the prosecutor's directions. But,it shows the limitations, because of a lack of understanding of a police officer's heavy workload. So, to accomplish the essential purpose of a stay of sentencing, a judging committee introduction is needed for ensuring the equality and fairness of a judgment in a stay of sentencing. Also, an observing duty of police officers has to be changed into probation duty to prevent the escape and the committing of a second offence. After investigating these plans, we need to complement, institutionally, by establishing basic rules which regarding the code of criminal procedure or recent probation. If these legal and institutional supplements are arranged, then the problems regarding the application of the law will be solved, and the execution of sentence of nation will be used efficiently, thereby gaining the essential purpose of the stay of sentence, which is used in a humanitarian sphere, can be viewed positively.

범죄피해자 구조제도의 문제점과 개선방안

권현식(Gwon Hyeon Shik) 한국피해자학회 2016 被害者學硏究 Vol.24 No.3

The great increase in injuries and death caused by violent and sophisticated forms of crime is a social phenomenon afflicting the current era of information explosion, globalization and individualism. In Korea, discussion on the protection of and restitution for victims of crime and providing aid for such victims led to the introduction in January 1981 of restitution order provisions for direct material damages and medical expenses due to criminal acts subject to the Act on Special Cases concerning Expedient Legal Proceedings (Act No. 3361). The Korean Constitution was amended in 1987 for the ninth time to include a provision stipulating that the right of a criminal victim to seek aid is one of the basic human rights (Article 30). On November 28, 1987, the Crime Victim Aid Act (Act No. 3969) was enacted, subsequently amended by the Crime Victim Protection Act (2005). Methods for protecting and providing necessary assistance to victims of crime were further introduced by the enactment of the Crime Victim Protection Fund Act in 2010. Despite such developments, the criminal justice system in Korea has been criticized for its insufficiency in providing aid for or supporting crime victims; many point out that it puts too much weight on upholding the rights of the accused. The purpose of this study is to suggest improvements in the victim support system by identifying the legal basis of victim aid programs and methods to address their shortcomings. This study aims to evaluate the very nature of the responsibility to aid victims of crime in relation to the legal and institutional status of the victim support system and provide policy directions so that relevant legal instruments can be amended accordingly. One of the ways to improve the victim support system in Korea is to establish a viable system where the rights of the victim are optimally ensured by fully restituting the victim for both economic and noneconomic damages and compensating for future losses. In addition, the victim support system provided under the Constitution must be understood as a form of legal reservation with an effect of creating fundamental rights. The system is not a mere statement of legislative policy, and thus the National Assembly must undertake bona fide fulfillment of its obligation for the requisite supplementary law-making for supporting victims of crime. To expand the scope of application of the victim support system and improve existing victim aid programs, Article 10 of the Korean Constitution, by which human dignity and values are guaranteed for all citizens and all have the right to pursue happiness, must be taken into consideration. As Article 34 of the Constitution stipulates that all citizens are entitled to a life worthy of a human being, the state has the duty to endeavor to facilitate social security and welfare, and citizens deemed not capable of earning a livelihood due to physical disability, disease or other reason shall be protected by the state. The understanding that the aforementioned provisions specify inviolable fundamental rights can form the basis for inducing nationwide support for further improving the existing victim support systems under Korean law.

자동변속기 유성기어 세트의 나선각 방향에 따른 동력손실 해석에 관한 연구

권현식(Hyun Sik Kwon) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11

라비뇨 타입 자동변속기의 기구학적 구성에 대한 조립 가능성 분석에 관한 연구

권현식(Hyun Sik Kwon) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.3

Automatic transmissions are standard equipment in most automotive vehicles because they provide smooth speed shifting and a compact design with multiple speed ratios. Their structure consists mainly of planetary gear sets as power-transmitting devices and brakes and clutches as shifting devices. Several forward and one reverse speed ratios are achieved by actuating shifting devices to connect gears, input and output shafts, and the transmission case. In the development of a new transmission, kinematic configurations reflecting the transmission concept design are required, and the ability of the new concept design to be assembled without any interference among the connections must be demonstrated. In this study, an assemblability analysis of the kinematic configurations of a Ravigneaux-type automatic transmission was conducted with an assemblable example of an 8-speed Ravigneaux-type automatic transmission.

전륜구동 차량용 자동변속기의 기구학적 구성에 대한 조립 가능성 분석에 관한 연구

권현식(Hyun Sik Kwon) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.11

An automotive automatic transmission is a popular power-transmitting device in passenger vehicles, as it provides various speed ratios for diverse driving conditions with easy manipulation and smooth gear shifting. The transmission is mainly composed of input and output shafts, planetary gear sets, brakes/clutches, and housing, and it yields multiple forward gears and one reverse gear by actuating the shifting devices of the brakes and clutches. In developing a new transmission, kinematic configurations of a transmission, which presents a brief structure and actuation schemes for speed ratios, need to be checked to determine if the structure can be assembled in a layout. It is impossible for a transmission concept having any interference in connecting main components to be developed further in the design process, since connection interference leads to failure of a layout design in the 2-D plane. In this research, an analysis of the assemblability of a front-wheel drive automatic transmission is carried out on an example concept design by applying the vertex addition algorithm based on graph theory.

자동변속기 적용 유성기어의 헬릭스 각 방향에 의한 쓰러스트 베어링 작용 축 하중 연구

권현식(Hyun Sik Kwon) 한국기계가공학회 2021 한국기계가공학회지 Vol.20 No.3

An automatic transmission, which consists of several decks of planetary gear sets, provides multiple speed and torque ratios by actuating brakes and clutches (mechanical friction components) for connecting central members of the planetary gear sets. The gear set consists of the sun gear, the ring gear, and the carrier supporting multiple planet gears with pin shafts. In designing a new automatic transmission, there are many steps to design and analyze: gears, brakes and clutches, shafts, and other mechanical components. Among them, selecting thrust bearings that not only allow the relative rotation of the central members and other mechanical components but also support axial forces coming from them is important; doing so yields superior driving performance and better fuel efficiency. In selecting thrust bearings, the magnitude of axial forces on them is a critical factor that affects their bearing size and performance; its results are systematically related to the direction of the helical angle of each planetary gear set (a geometric design profile). This research presents the effects of the helical angle direction on the axial forces acting on thrust bearings in an automatic transmission consisting of planetary gear sets. A model transmission was built by analyzing kinematics and power flows and by designing planetary gear sets. The results of the axial forces on thrust bearings were analyzed for all combinations of helix angle directions of the planetary gear sets.