• 자원환경지질
• /
• 제31권1호
• /
• pp.53-57
• /
• 1998

Transient electromagnetic (TEM) method is also affected by cultural and natural electromagnetic (EM) noises, since it uses part of the broadband ($10^{-2}$ to $10^5Hz$) spectrum. Especially, predominant EM noise which affects a moving transmitter-receiver TEM system is sensor motion-induced noise. This noise is caused by the sensor motion in the earth magnetic field. The technique for reducing the sensor motion-induced EM noise presented in this paper is based on Halverson stacking. This Halverson stacking is generally used in a time-domain induced polarisation (IP) system to reject DC offset and linear drift. According to spectrum analysis of the vertical component of sensor motion-induced noise, the frequency range affected by the motion of an EM sensor is less than about 700 Hz in this study. With the decrease of the frequency, the spectral power caused by the motion of a sensor increases. For example, at the frequency of 200 Hz, the spectral power of the sensor motion-induced noise is $-90dBVrms^2$ while the spectral power of the EM noise measured with a fixed sensor on the ground is $-105dBVrms^2$, and at the frequency of 100 Hz, the spectral power of the sensor motion-induced noise is $-70dBVrms^2$ while the spectral power of the EM noise measured with a fixed sensor on the ground is $-105dBVrms^2$. With applying Halverson stacking to an artificial noise transient generated by adding a noise-free transient to sensor motion-induced noise measured without pulsing, it is shown that the filtered transient is nearly consistent with the noise-free transient within a delay time of $0.5{{\mu}sec}$. The inversion obtained from this filtered transient is in accord with the true model with an error of 5%.

• Ocean and Polar Research
• /
• 제36권2호
• /
• pp.103-110
• /
• 2014

A wind-driven current in the East Sea from Lagrangian measurements of wind and current at 15 m using MiniMet drifters was analyzed. Spectral analysis of the current from 217 pieces of a 10 day-long time series shows the dominant energy at the inertial frequency for the current at 15 m. Wind has energy peaks at a 0.2-0.5 cycles per day (cpd) frequency band. The power spectrum of the clockwise rotating component is predominant for the current and was 1.5-2 times larger than the anticlockwise rotating component for wind. Co-spectra between the wind and current show two peak frequency bands at subinertial frequency and 0.5-0.3 cpd. Coherences between the wind and current at those peak frequencies are significant with 95% confidence and phase differences were $90-100^{\circ}$. From the phase differences, the efolding depth is estimated as 17 m and this e-folding depth is smaller than the estimation by Chereskin's (1999) 25 m using a moored Acoustic Doppler Current Profiler and an anemometer installed at the surface buoy. The angle between the wind-driven current (or ageostrophic current) and wind from this study was also much larger than the global estimate by Rio and Hernandez (2003) using reanalysis wind and drifters. The possible explanation for the discrepancy comes from the fact that the current is driven by a wind of smaller length scale than 250 km but the satellite or the reanalysis products do not resolve winds of length scale smaller than 250 km. Large rms differences between Mini-Met and QuickSCAT wind on spatial lags smaller than 175 km substantiate this explanation.

• 한국추진공학회지
• /
• 제22권4호
• /
• pp.61-67
• /
• 2018

액체로켓엔진용 산화제펌프의 캐비테이션 시험 중 입출구 배관과 펌프 케이싱에서 계측된 고주파 신호를 분석하였다. 각각의 데이터의 RMS 값을 캐비테이션 수에 따라 표현하였다. 또한 회전수 동기 주파수와 날개 개수 성분, 캐비테이션 불안정성 주파수의 크기를 검토하였다. 입출구 배관의 압력섭동은 캐비테이션 불안정성의 영향을 받았다. 출구 배관의 신호에서는 인듀서 날개 주파수인 3x 성분이 탁월하였다. 이러한 현상은 임펠러의 날개 개수가 인듀서의 날개 개수의 배수인 것과 관계가 있는 것으로 추정된다. 케이싱에 부착된 가속도계에서도 캐비테이션 불안정성 주파수가 확인되었다.

• 대한한의학회지
• /
• 제16권1호통권29호
• /
• pp.184-197
• /
• 1995

After 45 patients examined as to the result of medical treatment among the ones who came to Dept. of Pain Clinic, Oriental Medical Hospital, Chunju Woosuk University complaining low back pain chiefly from Dec/19/1994 to Feb/7/1995 for 50 days or so were observed clinically, the results were obtained as follows: 1. In duration of the case history, acute stage(37.8%) was the most predominant, and subacute stage(35.6%) and chronic stage(26.7%) were revealed in turn. 2. In opinions of radiation, Spondylosis(26.7%) was the most predominant, Scoliosis(15.6%) and HIVD(11.1%) were revealed in order, and 3 cases were revealed to be negative. 3. In the radiating pain of the lower limb, the radiating pains of the left lower limb were the most predominant and those of the right lower limb and those of both lower limbs were revealed in turn. By the way, 31.1% of patients didn't suffer from the radiating pain of the lower limb. 4. In the grade of the seriousness of subsective symptom, Grade 2(66.7%) was the most predominant, and Grade 3, Grade 4, and Grade 1 followed it in order. 5. In the period of the treatments of medi-acupuncture, 2-5 day treatments(31.1%) were major and 6-10 day treatments(26.7%), 16-20 day treatments(11.1%), 26-30 day treatments(11.1%), over 31 day treatments(11.1%), 11-15 day treatments(4.4%), and 21-25 day treatments(4.4%) followed it by turns. Thus 2-10 day treatments are 57.8% and under 30 day treatments are 57.8% of all. 6. In the frequency of use of each medi-acupuncture, V was most frequency used in 41 cases(91.1%), and 11 cases of HN(24.4%), 8 cases of MOK(17.8%), 4 cases of OK(8.9%), 2 cases of B(4.4%), and a case of I(2.2%) were revealed in turn. 7. In the effect of treatments, 10 cases(22.2%) were excellent, 25 cases(55.6%) were good, 5 cases(11.1%) were fair, and 5 cases(11.1%) were poor. As the result, 88.9% of all changed for the better and all of these were improved within the third trial. 8. The effect of the treatments per durations was 100% in acute stage, 93.8% in subacute stage, and 66.7% in chronic stage. According to that, it was reavealed that the rate of treatments decreased as it came near to the chronic stage. 9. The effect of treatments per radiating pains was 87.5% in the radiating pains of the left lower limb, 81.8% in those of the right lower limb, 100% in those of both lower limbs, and 92.9% in case that patients have no radiating pains. So in the rate of treatments on radiating pains of the lower limbs, the case of both sides or no radiating pains was higher than that of one side. 10. In the effect of treatments per the condition of patients, Grade 4 showed 100% of improvement, Grade 3 showed 90.9% of improvement, Grade 2 showed 86.7% of improvement, and Grade 1 showed 100% of improvement. 11. In the effect of treatments per contents of treatments, the group treated with medi-acupuncture therapy, herb medication therapy, acupuncture therapy, and physiothrapy at the same time(Group 1) showed 100% of improvement, the group treated with medi-acupuncture therapy, acupuncture therapy, and physiotherapy simultaneously(Group 2) showed 73.7% of improvement, and the group treated with medi-acupuncture therapy and acupuncture therapy at the same time(Group 3) showed 100% of improvement. 12. 2-5 day treatments showed 78.6% of improvement, 6-10 day treatments showed 91.7% of improvement, and over 31 day treatments showed 100% of improvement. As the result, genarally the longer the period of treatment was, the better the effect of treatment was. 13. When only V was used, the rate of treatment was 96.2%. When only HN was used, the rate of treatment was 100%. When only MOK was used, the rate of treatment was 100%. When V and HN were used at the same time, the rate of treatment was 33.3%. When V and MOK were used at the same time, the rate of treatment was 100%. When V and OK were used at the same time, the rate of treatment was 100%. When V, HN, and MOK were used at the same time, the rate of treatment was 100%. When V, OK, and MOK were used at the same time, the rate of treatment was 100%. When V, MOK, and B were used at the same time, the rate of treatment was 100%. When V, HN, OK, and I were used at the same time, the rate of treatment was 100%. When V, HN, and B were used at the same time, the rate of treatment was 100%.

• The Korean Journal of Ecology
• /
• 제20권6호
• /
• pp.405-411
• /
• 1997

Feeding behavior of the Russet Sparrow Passer rutilans was studied in two different types of habitats, shelter belts and isolated forests, in south-eastern Hokkaido, Japan, during the breeding seasons of 1995 and 1996. Predominant foods were determined as Caterpillar, Coleoptera, Diptera, Ephemeropera, Odonate and some other insects. The composition of the nestiling foods were not the same by season, region, and year. Larger foods in size were used by birds in isolated forests more frequently than in shelter belts. Amount of food per feeding was significantly larger in isolated forests than in shelter belts. Although food supply were more abundant in isolated forests than in shelter belts, the feeding frequency did not significantly differ between these two habitats. The nest density was higher in isolated forests than in shelter belts. Results of this study indicate that when the feeding condition is poor, birds tend not show specific food selection behavior, the feeding range is therefore larger, and the feeding interval is longer. Contrarily, the birds show a specific food selection behavior when they are in good feeding condition, the feeding range is therefor smaller and the feeding interval decreases.

• Journal of Chest Surgery
• /
• 제12권1호
• /
• pp.1-8
• /
• 1979

Pulmonary aspergillosis is being recognized with increasing frequency in recent years and the-rising incidence of this infection parallels certain medical advances in antibiotics, chemotherapeutic and immunosuppressive therapy. The cavities of lungs resulting from tuberculosis, histoplasmosis or neoplasm are apt, to be infected by one of the species of the genus Aspergillus and eventually mycetomas are formed within the cavities. Authors have experienced 6 cases of pulmonary aspergillosis forming mycetoma in Dept. of Thoracic Surgery, Catholic Medical Center from Aug. 1976 to Feb. 1979. Hemoptysis or blood tinged sputum, the predominant symptom, occurred in all cases. All patients underwent pulmonary resection, 1 pneumonectomy, 3 lobectomies, 1 lobectomy with segmental resection and 1 segmental resection and survived well without death or complication. Primary aspergillosis was in 2 cases and underlying diseases were present in 4 cases: 3 pulmonary tuberculosis, 1 bronchiectasis. The common diagnostic study of intracavitary mycetoma was the posterioanterior chest roentgenogram; in cavities suspected of being diseased or in doubtful cases, tomography was most available to find fungus ball with air-meniscus shadow.

• KSTLE International Journal
• /
• 제9권1_2호
• /
• pp.31-35
• /
• 2008

DLC (Diamond Like Carbon) films have predominant tribological properties like a high hardness, low friction and high chemical resistance; therefore, DLC films are applied in a wide range of industrial fields. This paper evaluated the characteristics of DLC films deposited on bearing steel with different hardness by RF-PECVD (Radio Frequency - Plasma Enhanced Chemical Vapor Deposition) method. Si-interlayer was deposited on bearing steel to improve adhesion strength by RF-Sputtering method. The DLC film structures were analyzed with Raman spectra and Gaussian function. Adhesion strength of DLC films was measured with a scratch tester. Friction and wear test were carried out with a ball-on -disc type to investigate the tribological characteristics. Experimental results showed that DLC films deposited on bearing steel under same deposition condition have typical structure DLC films regardless of hardness of bearing steel. Adhesion strength of DLC film is increased with a hardness of bearing steel. Friction coefficient of DLC film showed lower at the high hardness of bearing steel.

• Journal of Chest Surgery
• /
• 제27권12호
• /
• pp.1023-1026
• /
• 1994

We reviewed 10 cases of traumatic diaphragmatic injuries at Soonchunhyang University Gumi Hospital from January 1990 through April 1993. seven patients were male and three patients were female. The age distribution was ranged from 25 to 79 years, predominant 4th decades occurred in male. The traumatic diaphragmatic injuries were due to blunt trauma in 9 cases (traffic accident 7 and crash injury 2) and penetrating wound in 1 case (stab wound). The common symptom were dyspnea (60%), chest pain and abdominal pain in order frequency. In the blunt trauma and crash injury, te rupture site was all located in the left(9 cases). In the penetrating wound, the rupture site was located in the right(1 case). The surgical repair of 10 cases were performed with transthoracic approach in 9 cases and thoracoabodominal approach in 1 case. The postoperative mortality was 10% (1/10). The cause of death was multiple organ failure with pulmonary edema.

• Journal of Chest Surgery
• /
• 제27권12호
• /
• pp.1027-1030
• /
• 1994

We reviewed 10 cases of traumatic diaphragmatic injuries at Soonchunhyang University Gumi Hospital from January 1990 through April 1993. Seven patients were male and three patients were female. The age distribution was ranged from 25 to 79 years, predominant 4th decades occurred in male. The traumatic diaphragmatic injuries were due to blunt trauma in 9 cases[traffic accident 7 and crash injury 2] and penetrating wound in 1 case[stab wound]. The common symptoms were dyspnea[60%], chest pain and abdominal pain in order frequency. In the blunt trauma and crash injury, the rupture site was all located in the left[ 9 cases ]. In the penetrating wound, the rupture site was located in the right[1 case]. The surgical repair of 10 cases were performed with transthoracic approach in 9 cases and thoracoabdominal approach in 1 case. The postoperative mortality was 10%[1/10]. The cause of death was multiple organ failure with pulmonary edema.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 1997년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
• /
• pp.115-127
• /
• 1997

A study to evaluate the seismic response of $\frac{1}{2}$-scaled liquid storage tank constructed in Hualien, is performed. And this study is to identify the liquid-structure-soil interaction by observed earthquake data ans analyzed results. After the calculation of soil impedance for the test site by SASSI code, 3-dimensional seismic response analysis is performed by BEM-FEM-Impedance Method with the consideration of liquid-structure-soil interaction when the tank is excited by real earthquake. The observed acceleration and hydrodynamic pressure are compared with the numerical results. This comparisons show good agreement in predominant frequency and maximum hydrodynamic pressure. And the free surface sloshing motion due to earthquake loadings is computed in time domain.