• 디지털융복합연구
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• 제19권2호
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• pp.439-446
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• 2021

본 연구는 천연광물질로 나염 처리된 스포츠마스크가 방역마스크와 면마스크와 비교하여 주관적인 구취관련특성과 심리적 특성에서 차이가 있는 지 조사하는 것이다. 연구대상자는 스포츠마스크 군(Sports Mask Group) 30명, 방역마스크 군(KF Mask Group, KMG) 30명과 면 마스크 군(cotton mask group, CMG) 30명으로 나누어 총 90명의 대상자가 연구에 참가하였으며, 하루 1개, 3일 간 3개의 마스크를 사용하게 하였다. 또한 연구 기간은 2020년 10월 15일부터 2020년 10월 30일까지 실시하였다. 연구결과 구취건강과 구강건조 항목에서는 3군 간 차이가 없는 것으로 나타났지만 구강호흡과 구취자각도에서는 스포츠 마스크가 다른 마스크에 비하여 우수하게 나타났다. 심리적 요인을 분석한 결과 우울증은 3군 간 차이가 없는 것으로 나타났지만, 스트레스 요인에서는 스포츠마스크가 다른 마스크보다 스트레스지수가 감소된 것으로 나타났다. 연구의 결과는 기능성 마스크의 활용 방향성을 제시한 것으로써 가치가 있으며, 향후 연구될 기능성 마스크 연구의 기초 자료로 활용되길 바라는 바이다.

• Journal of Multimedia Information System
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• 제7권2호
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• pp.175-188
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• 2020

The paper focuses on conception and development of complex systems composed mainly by a pump syringe subsystem and an electronically injector that facilitates patients saving data operation for medical staff use. We successfully developed conventional approaches for medical system staff requirements, such as system boundary conditions. Decisions at a given level are studied. We propose a complex system architecture, based mainly on patients collected data and ordered stepper injection parameters. System is successfully simulated and prototyped. Design and implement tests are accomplished, the proposed system ensures both the electric syringe pump and the electric injector operation. In addition, this new system introduces several additional options as patient database development and automation injection operation. Development and software operating tests to create a visualization control interface are validated. The solution performs syringe function and electronic injector. User can manage a syringe in two C modes of technology. We propose a program composed of two linked parts. If an error such radiologist bad target selection is made, an image with lower intrinsic quality emerges. Developed Shoot syringe different electronic cards are simulated and prototyped, in addition, maps are driven, prototype. All tests results are accomplished.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2609-2614
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• 2007

Shell & Tube type Oil Cooler is widely used for hydraulic presses, die casting machines, generation equipments, machine tools and construction heavy machinery. Temperature of oil in the hydraulic system changes viscosity and thickness of oil film. They have a bad effect to performance and lubrication of hydraulic machinery, so it is important to know exactly the heat exchanging efficiency of oil cooler for controlling oil temperature. But most Korean manufacturers do not have test equipment for oil cooler, so they cannot carry out the efficiency test of oil cooler and it is impossible to verify its performance. This paper includes information of construction of necessary utilities for oil cooler test and design and manufacture of test equipment. One can select the optimum product by obtaining performance data through tests of various kinds of oil coolers. And also the paper developed a program which can be easily used for design of 2D and 3D drawings of oil cooler.

• 유통과학연구
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• 제15권5호
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• pp.5-15
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• 2017

Purpose - This research identified the factors to be considered when CEOs establish small companies and improve their businesses by analyzing the effects of their entrepreneurship and marketing activities on the business performance of small companies and suggested measures to utilize them strategically. Research design, data, and methodology - The research conducted a survey for companies located in Busan, and Gyeongnam area in Korea. To verify the model and hypothesis mentioned above, relevant items were allocated to each variable. Results - the research found that the innovation of entrepreneurship negatively affects formalization and centralization along with the propensity for risk-taking which negatively affects all the characteristics of an organization's structure. It was also found that the pro-activeness which was rejected in the selection and verification of hypothesis is the CEOs characteristics which positively affect all of the organization type are contrary to the initial hypothesis. Conclusions - The results of these efforts will positively contribute toward developing a start-up strategy helpful for small companies CEOs, to change the business environment proactively, to operate their organization efficiently and to develop market-oriented marketing activities and objectives. This research found the role of market-oriented characteristics demanded by the CEO to overcome organizational structure, business innovation and bad business situations.

• Journal of Electrical Engineering and information Science
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• 제2권6호
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• pp.95-105
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• 1997

In this paper, we have studied about design and fabrication of the actively shielded superconducting MRI magnet. Nonlinear optimization methods are usually used to find optimum coil configurations. However the selection of initial coil configurations is very difficult. In case bad initial data are used, it is even impossible to find optimum coil configurations which satisfy predefined constraints. We have developed computer optimization program which consists of two steps. Initial coil configurations are easily selected through linear optimization in the first step and optimum coil configurations are found through nonlinear optimization in the second step. We have also studied about superconducting shim coils to cancel error fields caused by coil fabrication errors. Many researchers published design concepts of shim coil. However all these studies are for shim coil design using filamentary coils with single turn, Shim coils with multi-turns should be used to produce enough field strength to cancel error fields. We have developed computer program for the design of shim coils which have proper thickness and length. An actively shielded superconducting MRI magnet with a small warm bore was fabricated and four sets of superconducting shim coils were equipped. The magnetic field distributions were measured and field correction was carried out using shim coils.

• 응용통계연구
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• 제20권3호
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• pp.551-559
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• 2007

로지스틱회귀에서 일반적으로 사용되는 최대우도추정법은 이상점에 대해 로버스트 하지 않다. 따라서 본 논문에서는 로지스틱회귀모형의 로버스트 추정을 위한 알고리즘을 제안하고자 한다. 이 알고리즘은 V-마스크 형태의 경계기준에 의해 나쁜 지렛점과 수직이상점을 식별하고, 식별 결과를 바탕으로 이상점의 영향력을 감소시키기 위한 효과적인 방안을 모색한다. 이상점의 영향력 감소는 가중치와 조정치를 적절히 선정함으로 가능하며, 그 결과 붕괴점이 높은 추정치를 얻게 된다. 제안된 알고리즘을 다양한 자료에 적용하여 정분류율을 측정하여 비교하였는데, 새로운 알고리즘이 최대우도추정보다 정확한 분류를 해 주는 것으로 평가되었다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.158-159
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• 2011

Energy efficiency in wireless sensor networks (WSNs) is one significant factor that needs to be considered when making any designs or doing any enhancements on the communication protocol stack. In WSNs using traditional geographic routing, when a sensor node receives a data packet that needs to be transmitted to the sink, it will forward the packet to the neighbor node which is closest to the sink. The traditional geographic routing assumes that the link quality is always 100%. This may cause a bad result as per which we waste too many energy for retransmissions between the two nodes. Thus, the problem here is how to select such node as forwarder at most efficiently in the aspect of both energy consumption and the distance toward the destination. The better node we choose, the more energy we can conserve for the whole network. In this paper, we propose a next-hop forwarding selection metric, called Energy Consumption for Transmission (ECT), which can resolve the above problem in the best way.

• 한국인쇄학회지
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• 제31권1호
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• pp.1-14
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• 2013

Screen printing is a printing method with flexible plate surface characteristics. In addition, since the appearance of electronics industry the screen printing has been demanding high quality and definition. However, Screen printing is a method for taking ink through mesh opening because screen mesh tends to restrict quality of screen printing. In particular, the biggest problem compared with other printing type is halftone reproduction characteristics. Halftone reproduction characteristics for screen printing depend on screen mesh and opening. Dot losses or dot gains are observed through various types of screen mesh because thread of screen mesh interfere with the movement of the ink. Excessive dot losses or gains can affect the tonal range. Furthermore, this problem can result in other problem such as bad contrast and gray balance. Therefore, it is an important factor to use proper screen mesh for halftone screen printing. However, domestic screen printing industry relies on worker's experience in field rather than depending on objective data although standardized specifications and optimal printing conditions are required for screen printing. For this reason, it is important to stipulate standard condition for domestic screen printing industry. Therefore, it was examined to find tonal range by mesh opening in halftone prints process of screen printing used domestic paper and ink in this study. In addition, TVI(Tone Value Increase) characteristic was observed by comparing to the manuscripts and prints of the dot area ratio. Furthermore, contrast value and gray balance were confirmed for each condition of the printout. Conditions for the proper selection of screen mesh screen for the quality of the prints were also examined, compared with the international standard of screen printing, ISO 12647-5.

• 대한치과기공학회지
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• 제34권3호
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• pp.291-302
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• 2012

Purpose: It is to survey old men's utilization status of dental clinic and temporary-binding dentures and then to provide basic data to make a program for manufacturing old men's dentures and their teeth health education. Methods: Random selection was made on old men living in Daejeon and Chungnam, and a survey was conducted from April 15 to May 20, 2011. 500 questionnaires were distributed and 420 questionnaires were collected. Using spss 18.0 program, final analysis was made on 363 questionnaires except for 57 questionnaires which had missing value or showed some doubts about the unreliability. Results: 1. With respect to number of natural teeth as per the age, the upper/lower jaws had meaningful differences (P<.001), which means that the older the person is, the smaller number of natural teeth is. In the meantime, there was no meaningful difference according to sex. 2. With respect to kind of prosthetics installed in a mouth as per the age, there was meaningful difference in the upper jaws (P<.05) but there was no meaningful difference in the lower jaws. It was found out that the older the persons are, the more they use removable dentures while the younger the persons are, the more they use fixed partial dentures. 3. With respect to mouth health condition recognized by oneself, it showed bad (44.4%) and good (10.3%),which means recognition as bad is greater, and the age when prosthetics were first used is dispersed variously from below 40 to over 70. 4. Dental care institutions which they mainly used are hospital and clinics (91.5%), and 66.4% of them visited dental clinics lately. Preferential treatment if they go to dentists is as follows in the order of prosthetics (33.9%), gum treatment (24.2%) and pain treatment (14.9%). 5. 68.4% of them revisited dentists after installation of dentures and the reason for revisit is as follows in the order of poorly fitted dentures (35.1%), painful gum 25.9%, regular check-up 25.4% and difficult chewing 9.6%. Conclusion: As our country enters into an aging society, mouth health problem of old men has come to a serious issue, and therefore, a survey was conducted on some old men with respect to their utilization status of dental clinic and removable dentures in order to provide basic data for improvement of quality of their life, maintenance and enhancement of their mouth health. The study result shows that the older they are, the higher the loss rate of teeth as well as needs for prosthetics are, and thus it is thought the study will help to develop mouth health education program which may improve quality of old men's life by recovery of mouth functions declined due to loss of teeth and by regular check-up, education for mouth health control and following-up control of dentures.

• 한국대기환경학회지
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• 제21권1호
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• pp.97-105
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• 2005

본 연구는 복잡한 도시 대기환경 모의에 사용된 중규모 기상장 모델이 모수화 방법이나 해상도 등과 같은 물리적 한계를 갖는 점에 대해 관측값 객관분석과 그 내삽되는 자료의 조절과정 (Quality control)이 대기유동장 수치모의에 미치는 효과의 검증을 위해 설계되었으며, 한 적절한 자료의 조절방법을 제시하였다. 먼저 기상 관측소의 지점위치에 따른 Quality control결과에서는 도심 내에 위치한 기상관측자료들은 주변에 다수 존재할 가능성이 큰 건물과 지형이 주는 영향에 의해 대표성이 떨어지는 자료를 생산할 가능성이 있는 것으로 나타났으며, 오히려 해수ㆍ담수 부근지역에 위치하여 일관된 바람장과 기온장을 형성하는 자료들이 모델 내에서 자료의 대표성이 특히 기온보다는 풍속에서 나타나고 있다. 모델 내에서 역학적인 관계를 만족시키는 관측값의 유효성에 대한 Quality control 결과 기온이 풍속보다 향상되고 있는 것으로 나타났으며 가능한 한 모델링 도메인 영역에 포함되어 있는 기상 자료들을 많이 내삽하는 것이 더 효과적으로 모델의 해석능력을 향상시키는 것으로 나타났다 이것은 대표성있는 어떤 지점의 선택보다는 모델 내에서 크게 고려되지 않았던 복잡한 도심의 아스팔트, 건물, 지하철, 도로, 자동차등에 의해 발생될 가능성이 있는 열에 대한 정보의 반영은 결과적으로 모델의 해석에 유리하게 적용되며, 서울을 비롯한 수도권지역의 AWS에 포함되어있는 기온자료는 모델 내에서 정체되거나 확장되어 있는 고온역에 대한 모사에 적절하게 사용될 수 있음을 나타낸다.