• Design & Manufacturing
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• 제14권1호
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• pp.42-48
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• 2020

Titanium alloy has been in the spotlight as a core material in high-tech industries that require high strength and light weight because it has excellent strength and corrosion resistance and strength is higher than that of steel. Therefore, in various industries, existing steel products are intended to be replaced with titanium alloys. Titanium alloys can cause cutting tool breakage during cutting, and heat generated during cutting does not dissipate, accumulates in tools and workpieces, resulting in large wear and tear on thin workpieces. In addition, since titanium alloy is a metal with high chemical activity, the wear of the tool becomes more severe when the cutting speed is high, so machining of titanium bolt through cutting is very disadvantageous in terms of productivity. Therefore, the production of bolts using titanium alloys is being produced through a forging process to improve productivity and product quality. In this paper, hot forging molding analysis was performed on bolts used for fastening automobile parts using Ti-6Al-4V alloy, which is the most commonly used titanium alloy.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.354-361
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• 2005

In high speed cutting process, due to the friction between the tool and workpiece, a temperature rise of contacting part is serious. It need to develop cutting tool for overcoming such a poor condition. So now, some studies, the optimization of tool shapes, the fine grains of tool material, multi-layer coating of tools are processing. If mirror finishing on the tool is processed, there is advantage of relation between chip and tool, because of less friction, and also tool's lift would be increased. As a result mirror like finishing is expected efficient enhancement of tool. Generally, it is too difficult to process by a general way for tools of complex shapes, it is required a new method to process such complex shape tools. The magnetic fluid polishing technique can polish the workpiece of complex shape, because the polishing method which polishes as compress the workpiece by the magnetism abrasives to arrange to the linear according to the line of magnetic force. In this paper, We polished the surface of the high speed cutting tool using the magnetic fluid polishing technique, to enhance the performance of the high speed cutting tool.

• 지질공학
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• 제4권1호
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• pp.29-42
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• 1994

한반도 남부의 순수 대륙을 통과한 지진파를 가지고 미소지진과 지하 인공 폭발의 구별에 관한 연구를 한다.지하 인공 폭발과 미소지진긔 파형 특성은 관측 및 이론 지진 기록지를 가지고 수행한다. 이러한 지지파 파형 특성은 주로 진원메키니즘이 전파 과정보다 강한 영향을 미친다. 미소지진에서는 double-couple진원,그리고 폭발에서는 single-couple진원이 주어진다. 진원이 아주 천부층에 있을때 Rayleigh파의 fundamental mode(1-6초 주기)인 $R_g$파와 guide파인 $L_g$파(8-12초 주기)가 장 나타난다. 또한 폭발에서 SH파는 nodal line이 없기 때문에 초동 진폭이 약하게 나타나을 알 수있다. 인공폭발의 이론 지진 기록지는 압축 초동의 P파와 $R_g{\;}및{\;}L_g$파가 나타남을 알 수있다. 그 반면에 전자의 초동은 관측점에 따라 압축(compression)과 팽창 (dilatation)이 나타났고 Lg파는 복잡하고 $R_g$파는 깊이가 커짐에 따라 사라지는 것을 알 수 있다.

• 한국음향학회지
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• 제36권3호
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• pp.158-164
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• 2017

수중에서 은밀하게 움직이는 표적을 조기에 탐지하기 위한 선배열센서에 적용되는 통상의 하이드로폰은 표적신호의 크기만 측정할 뿐, 외부에서 들어오는 음향신호의 방향은 파악할 수 없는 한계가 있다. 이에 본 연구에서는 표적으로부터의 음향신호의 크기와 방향을 동시에 탐지할 수 있는 관성형 벡터 하이드로폰의 기본 구성품으로 두께 전단형 진동자를 제안하였다. 외력에 대한 진동자의 출력 전압을 해석할 수 있는 수식을 유도하였으며, PMN-PT 단결정 진동자에 대한 유한요소해석을 통해 수식의 타당성을 검증하였다. 본 연구에서 얻어진 해석 결과는 향후 두께 전단형 진동자로 구성된 관성형 벡터 하이드로폰 설계에 활용될 것이다.

• 혜화의학회지
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• 제21권2호
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• pp.21-36
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• 2013

Jeol-sik, (festive seasons every 15 days based on sun cycle), refers to both Korean Traditional Festival food(jeol-sik), intertwined between months, and in-season meals(si-jeol-sik) in which the ingredients used are produced in each and one of the four season. Si-jeol-sik is a kind of recommendatory food, which is combined to seasonal changes. I found that ingredients in Si-jeol-sik of spring are helpful for strengthening one's life force. Moreover, the ingredients also reflects seasonal changes. The main ingredient of Si-jeol-sik in January(in lunar year) is rice. Rice is good for upgrading one's stomach qi(energy). Rice continues to be used in February. In addition, some greens are included in February Si-jeol-sik as to help defecation. In March, the ingredients become diverse and abundant. The main concern in the ingredients found in March is not limited to stomach qi. These changes of ingredients are in line with the concept of 'health maintenance', which is written in Huangdi Neijing. The writing teaches the wisdom of adaptation to nature. Si-jeol-sik's basic idea is maybe giving people some food, which includes useful elements to help them survive through a season or the next season. They can be also explained properly by the help of five flavours theory. According to Huangdi Neijing liver is main organ of spring. So liver is more important than other organs in spring. And the most efficient way for liver is supplying sweet or sour food. Interestingly, there are many sweet elements in Si-jeol-sik of spring.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2002년도 춘계학술대회논문집
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• pp.21-32
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• 2002

In accordance with the development plans of Ulsan harbor, Ulsan new harbor will be contructed considering supporting Ulsan harbor as a safe berthing and departure at single buoy mooring(SBM). In this study, we used a full-mission ship handling simulator adopting 300,000 DWT VLCC manoeuvered at the planned Ulsan SBM. Five masters who have had a long experience of ship maneuvering were called to carry out the simulations, of which each scenario were tried one, completed total of 68 times. The marine traffic safety was assessed in terms of 1) the closest point of approach(CPA) to other SBM and breakwater in the vicinity and the probability of crossing the restricted area of the closest SBM and fairway limit, 2) subjective evaluation such as the mental burden and the maneuvering difficulty of shiphanders, and 3) the opinions of shiphandlers. From the result of this simulation, we have a conclusion as follows; First, because crude oil berthing angle is so small by current S-OiL Co. crude oil buoy by SK Co. No 3 crude oil buoy different view SK Co. No 3 crude oil buoy and interference of current KNOC crude oil buoy, Berthing is impossible, and Emergency departing is very dangerous too operation impossible. Second it is desirable that SK Co. No 2 and No 3 Single buoy Mooring that do different view controls position so that to be not put in straight line each other. Third, SK Co. No 1 and 2 single buoy mooring that do different view to Onsanhang berthing and departing is seized by single buoy mooring by external force ship that set sail does faith control need.

• 한국중재학회지:중재연구
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• 제30권1호
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• pp.39-66
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• 2020

Under the doctrine of separability, if the party did not specifically challenge the validity of the arbitration clause, then it is presumed valid, and arbitrators would still have authority to adjudicate disputes within the scope of the arbitration clause. Further, the Primerica and Spahr decisions address whether a court or an arbitrator should adjudicate a claim that a contract containing an arbitration clause is void ab initio due to mental incapacity. If the arbitration agreement is separable, as was found in Primerica, then the "making" of the agreement is not at issue when the challenge is directed at the entire contract and arbitrators may exercise authority. If an arbitration provision is not separable from the underlying contract, as in Spahr, a defense of mental incapacity necessarily goes against both the entire contract and the arbitration agreement, so the "making" of the agreement to arbitrate is at issue, and the claim is for courts to decide. Although no bright line rule can be established to deal with challenges of lack of mental capacity to an arbitration agreement, the rule in Prima Paint should not be extended to this defense. Extending the rule in Prima Paint would force an individual with a mental incapacity to elect between challenging the entire contract and challenging arbitration. Accordingly, there should be a special set of rules outside of the context of Prima Paint to address the situation of status-based defenses, specifically mental capacity defenses, to contracts containing arbitration provisions.

• 대한소아치과학회지
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• 제30권3호
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• pp.465-470
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• 2003

소아에서 영구 전치부에 강한 외상이 가해지는 경우 단순한 수평파절보다는 비스듬한 수직-수평파절을 보이는 경우가 많으며 파절선이 치은연하로 위치되는 경우도 많은데 그러한 경우 최근에 의도적 재식술을 이용한 치료가 많이 시도되고 있다. 파절치를 탈구시킨 후 순설측을 뒤바꿔서 재식할 경우치근의 방향 차이로 인하여 발치와에서 상방으로 위치되면서 치관의 길이를 증가시킬 수 있으며 파절선을 순측에 위치시켜 시야확보를 용이하게 할 수 있다. 본 증례에서는 치아외상으로 상악 중절치가 치관-치근 파절된 혼합치열기 환아에서 파절치를 $180^{\circ}$ 회전시켜 의도적 재식술을 시행하여 치료한 후 양호한 결과를 얻었다. 이에 예전의 치료방법과 더불어 회전을 이용한 의도적 재식술은 치관-치근 파절치의 또다른 치료 방법이 되리라 사료된다.

• 한국가스학회지
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• 제19권3호
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• pp.49-53
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• 2015

이 논문의 목적은 자동차 클러치, 수동변속기와 타이어 시스템의 마찰에 관련된 화재에 대한 고장사례를 분석하고 연구하는 것이다. 첫 번째 사례는 반복적으로 클러칭하면서 자동차의 클러치 디스크가 플라이 휠의 접촉면과 접촉하면서 열에 의해 과열되어 이 열이 수동변속기의 외부로 흘러 고착된 오일 찌꺼기에 옮겨 붙어 화재가 발생된 것으로 확인되었다. 두 번째, 사례로 변속 장치는 기어와 기어의 접촉에 의해 동력을 전달한다. 변속기 오일이 변속기 케이스의 균열로 인해 오일 부족 현상이 일어나 변속기 케이스 상단의 퇴적물에 의해 화재가 발생된 것을 확인하였다. 세번째 사례는 건조한 구덩이에서 빠져나오려고 반복적으로 가속페달을 작동시키면서 타이어와 도로의 마찰이 반복되면서 내부의 축적된 열에 의해서 화재가 발생된 것으로 확인되었다. 따라서, 운전자는 운전 중 마찰부에 화재가 발생하지 않도록 세심하게 관리하여야 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권4호
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• pp.1344-1367
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• 2014

Mobile traffic is increasing a masse because of the propagation of the Internet and the development of wireless mobile technology. Accordingly, the Network Local Mobility Management (NETLMM) working group [1] of the Internet Engineering Task Force (IETF) has standardized Proxy Mobile IPv6 (PMIPv6) [2] as a protocol for accomplishing the transmissibility of mobile terminals. PMIPv6 is a network-led IP-based mobility management protocol, which can control terminal mobility without depending on the type of access system or the capability of the terminal. By combining PMIPv6 and the mobility of Session Initiation Protocol (SIP), we can establish terminal mobility and session mobility through a more effective route. The mobility function can be improved and the overlap of function reduced as compared to that in the case of independent operation. PMIPv6 is appropriate for a non-real-time service using TCP, and SIP is appropriate for a real-time service using RTP/UDP. Thus, in the case of a terminal using both services, an effective mobility management is possible only by using PMIPv6 together with SIP. In order to manage mobility in this manner, researches on PMIPv6-SIP are in progress. In line with this trend, this paper suggests a new PMIPv6-SIP architecture where when a mobile terminal conducts a handover, a network-led handover while maintaining the session without the addition of a special function or middleware is possible along with effective performance evaluation through mathematical modeling by comparing the delay and the packet loss that occur during the handover to the Pure-SIP.