• 대한치과교정학회지
• /
• 제41권5호
• /
• pp.354-360
• /
• 2011

Objective: To investigate the effects of different pilot-drilling methods on the biomechanical stability of self-tapping mini-implant systems at the time of placement in and removal from artificial bone blocks. Methods: Two types of artificial bone blocks (2-mm and 4-mm, 102-pounds per cubic foot [102-PCF] polyurethane foam layered over 100-mm, 40-PCF polyurethane foam) were custom-fabricated. Eight mini-implants were placed using the conventional motor-driven pilot-drilling method and another 8 mini-implants were placed using a novel manual pilot-drilling method (using a manual drill) within each of the 2-mm and 4-mm layered blocks. The maximum torque values at insertion and removal of the mini-implants were measured, and the total energy was calculated. The data were statistically analyzed using linear regression analysis. Results: The maximum insertion torque was similar regardless of block thickness or pilot-drilling method. Regardless of the pilot-drilling method, the maximum removal torque for the 4-mm block was statistically higher than that for the 2-mm block. For a given block, the total energy at both insertion and removal of the mini-implant for the manual pilot-drilling method were statistically higher than those for the motor-driven pilot-drilling method. Further, the total energies at removal for the 2-mm block was higher than that for the 4-mm block, but the energies at insertion were not influenced by the type of bone blocks. Conclusions: During the insertion and removal of mini-implants in artificial bone blocks, the effect of the manual pilot-drilling method on energy usage was similar to that of the conventional, motor-driven pilot-drilling method.

• 동의생리병리학회지
• /
• 제32권4호
• /
• pp.271-276
• /
• 2018

The purpose of pilot clinical trial is to evaluate the efficacy and safety of acupuncture therapy on TEWL(Transepidermal Water Loss) and skin hydration. A total of 36 human who visited Dongshin University Oriental Medical Center from October 2nd, 2015 to July 31st, 2016 were included in the pilot clinical trial. Acupuncture therapy was performed at Gokji(LI11) and Daechu(GV14). We observed change of TEWL(Transepidermal Water Loss), skin hydration before and after acupuncture therapy. In the primary endpoint, index of TEWL showed a statistically significant decline($8.01{\pm}2.55{\rightarrow}6.58{\pm}1.97g/h/m2$, $7.40{\pm}2.65{\rightarrow}4.99{\pm}1.89g/h/m2$). Index of skin hydration showed statistical significance($52.83{\pm}6.53{\rightarrow}56.82{\pm}7.24$, $63.50{\pm}8.57{\rightarrow}64.96{\pm}8.48$). To evaluate the safety, vital sign check were conducted and showed no statistically significant result. And there were no severe adverse events during this study. According to the above pilot clinical trial, it is suggested acupuncture therapy were effective for skin moisturizing.

• 한국통신학회논문지
• /
• 제30권12C호
• /
• pp.1186-1192
• /
• 2005

본 논문에서는 주파수 인터리빙이 적용된 다중 반송파-부호 분할 다중 접속 (MC-CDMA: Multicarrier code division multiple access)에서 파일럿 채별 기반의 새로운 채별 추정 기법을 제안한다. 주파수 차원에서 칩 인터리빙 (CI: chip interleaving)된 MC-CDMA 시스템은 일반적인 심별 인터리빙을 적용한 시스템보다 더 큰 주파수 다이버시티 이득을 얻을 수 있는 장점을 가진다. 그러나 CI-MC-CDMA에서는 채널의 상관 대역 내에서 파일럿 채널과 데이터는 서로 직교하지 않으므로 일반적인 파일럿 채널 기반의 채널 추정 기법 (PCCE: pilot channel-based channel estimation)은 사용이 불가능하다. 제안된 채널 추정 기법은 두 개의 연속된 부반송파에서 데이터와 파일럿 채널이 서로 직교성을 유지하도록 시스템 구조를 변경하여 파일럿 채널을 사용하여 적은 연산량으로 정확한 채널 추정을 가능하게 한다.

• 한국통신학회논문지
• /
• 제39C권6호
• /
• pp.482-489
• /
• 2014

본 논문은 IEEE 802.11 환경에서 새로운 AP를 탐색하기 위한 네트워크 스캐닝의 기존 방식을 802.11k의 Measurement Pilot을 활용하여 개선하는 새로운 알고리즘을 제안한다. 그리고 제안한 알고리즘과 종래의 알고리즘을 시뮬레이션 환경에서 비교하여 분석한다. 일반적인 IEEE 802.11을 사용하는 기기들은 탐색 시간이 짧다는 장점을 갖는 능동 탐색(Active Scan)방식을 활용한다. 하지만 이 방식은 수동 탐색(Passive Scan) 방식에 비해 많은 전력사용을 필요로 한다. 본 논문에서 제안하는 탐색 알고리즘은 IEEE 802.11k에서 활용되는 비컨(Beacon)보다 짧은 주기를 갖는 Measurement Pilot을 활용하여 수동 탐색과 능동 탐색의 장점을 취합하여 전력사용을 줄인다.

• 대한예방한의학회지
• /
• 제22권2호
• /
• pp.25-32
• /
• 2018

Objectives : This study was conducted to investigate the frequent diseases among the people who had been treated by collaborative treatment of Korean medicine and Western medicine, and to compare their medical use behaviors before and after the collaborative first-stage pilot project between Korean medicine and Western medicine. Methods : 4,467 patients were identified as the patients who are participated in the collaborative first-stage pilot project between Korean medicine and Western medicine during the period between July 15, 2016 and March 31 2017. We used 28,480 records of Korean national health insurance claim data from January 1 2016 to March 31 2017 to analyzed present condition of cooperative medical usage. Also we conducted a paired t test to compare the percentage of collaborative treatment days before and after the pilot project period. Results : We found that the most frequent diseases treated in the pilot project were the diseases of musculoskeletal and nervous system and then 10 major diseases such as H, K, J, C (D), N, L, E, A, H and F disease codes in order. Also it was confirmed that 14 major and 53 medium diseases are included from more than 90% of total patients. As a result of high frequency of medical treatment in Western medicine or Korean medicine is "administration of Korean medicine", which is same as before and within the pilot project. The ratio of utilizing both Western and Korean medical care for the same disease on the same day by both general patients and patients in KCD-7 disease code group C, G, I, M and S had been increased significantly. Conclusions : The pilot project might change the behavior of utilizing the medical care service by increasing the ratio of collaborative treatment of Western medicine and Korean medicine for the same disease on the same day.

• 한국통신학회논문지
• /
• 제33권8C호
• /
• pp.613-616
• /
• 2008

In this paper, a fine residual frequency offset estimation scheme is proposed for multiband orthogonal frequency division multiplexing ultra-wideband (MB-OFDM UWB) systems. The basic idea of our approach is based on the fact that two adjacent OFDM symbols carry the identical information in the MB-OFDM UWB system, thus removing the need of pilot symbols. The mean square error of the synchronization scheme is evaluated and simulation results are used to verify the effectiveness of the proposed estimator. When compared to the pilot-aided conventional estimator, the proposed estimator has a lower estimation error.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 추계학술대회 논문집
• /
• pp.725-728
• /
• 2002

In this Paper, a mathematical model describing the dynamics of pilot operated pressure control valve was derived. A attempt to analyze the Parameters(seat diameter, cone angle, spring stiffness, control volume) which relate to the performance of the object valve was carried out. Simulation using AMESim as a simulation tool was operated, and verified the validity of our simulation by means of comparison our simulation results with an experimental results of the pilot operated pressure control valve.

• 한국항공운항학회지
• /
• 제8권1호
• /
• pp.111-124
• /
• 2000

In this study, pilot's read-back errors were reviewed in terms of its cause and consequence while FAA tried to weigh a new initiative in the atc-pilot communication dispute in opposition of a majority of the aviation community by addressing an interpretive rule of 14CFR 91. Especially human factors in ATC communications were outlined with a view to suggest a line of recommendations for a successful accomplishment of safe flight in the busy terminal airspace.

• 한국통신학회논문지
• /
• 제22권3호
• /
• pp.562-570
• /
• 1997

In Direct Sequence Code Division Multiple Access(DS/CDMA) communication systems, it is important to contraol the power of reverse link channel evenly for overall channel capacity. To control the reverse link powers efficiently, it is necessary to estimate signal quality of each reverse link channel. In this paper, we discuss a method to estimate the signal-to-noise ratio(SNR) for each channel by measuring the powers of pilot and noises. Computer simulations are done to show the effectiveness of the scheme.

• 한국항공운항학회지
• /
• 제31권4호
• /
• pp.126-132
• /
• 2023

During the COVID-19 pandemic, there have been many changes in the aviation industry as a whole. Passenger traffic has decreased, but on the contrary, the international transport demand for cargo planes has never been higher. Due to their geopolitical location when flying to major cities around the world, Korea's international pilots are bound to have relatively more jet lag-causing routes than their American or European-based pilots. Through this study, we tried to analyze the degree of fatigue and fatigue weighting factors according to operating conditions for domestic pilots. As a result of the study, the following conclusions were drawn. Despite the variety of models, routes, and fatigue between individuals, it was found that the 3 Pilot operation route was concentrated as a representative fatigue route. Most of the individual fatigue improvement request sections showed higher fatigue as the night flight section was longer among the 3Pilot routes for more than 12 hours, and 43 out of 90 participants (Korean Air pilots) focused on 3Pilot (two captains and one pilot) as fatigue-intensive operating conditions. Therefore, it proposes an improvement in the system of applying 12-hour unification standards according to Korea's geopolitical international operating conditions and time difference standards.