This study deals with the design of the marine antenna stabilization for an efficient 6 Degrees of Freedom(DOF) motion of a ship. Marine antenna must have abilities to target center and at the same time to stabilize the antenna dish in order to maintain its orientation toward the communication center. In order to achieve such requirements, structure stability and dynamics analysis to role to set up the simulation model. Prototype model designed and implemented into the DMU(Digital Mock Up) and MBD(Multi Body Dynamics) analysis method. Those simulation method has been carried out to stabilize the antenna under the ship motion. Simulation results show that the verification of structural stability better performance for marine antenna

The purpose of this study was to examine the effects of abdominal hollowing with ultrasound biofeedback on multifidus and transversus abdominis/internal oblique muscle activities during lifting tasks. This study recruited 12 healthy men. All subjects received training on expiration without and with abdominal hollowing with ultrasound biofeedback. After receiving training for each condition, the thickness of transversus abdominis was measured using ultrasound, and then, electromyography activities of transversus abdominis/internal oblique and multifidus during lifting tasks were measured using a surface electromyography system. The differences in thickness of transversus abdominis and electromyography activities of transversus abdominis/ internal oblique and multifidus between the two conditions were analyzed using paired t-test. Thickness of transversus abdominis and transversus abdominis/internal oblique and multifidus activities were significantly increased during expiration with abdominal hollowing with ultrasound biofeedback compared to during expiration without abdominal hollowing (p < 0.05). These findings suggest that abdominal hollowing with ultrasound biofeedback is effective in increasing trunk stabilizer muscle activities during both static and dynamic tasks such as lifting.

Background: Scapular winging is a prominence of the entire scapular medial border, mainly caused by insufficient activity of the serratus anterior (SA) and imbalance of scapulothoracic muscles. Push-up plus (PUP) exercise has been commonly used to increase SA muscle activity. The facilitation of abdominal muscle may affect scapular muscle activity by myofascial connections. Thus, the sequential activation of the turnk muscles is suggested to facilitate the transition of proper force from upper limb and restore force couple of scapular muscles. The abdominal drawing-in maneuver (ADIM) has been effective in improving activation of the deep trunk muscles during movement. Objects: The aim of this study was to determine the effect of ADIM on the activity of the upper trapezius (UT), lower trapezius (LT), and SA during PUP exercises in subjects with scapular winging. Methods: Fourteen men with scapular winging (determined as a of distance between the scapular medial border and thoracic wall over 3 ㎝) volunteered for our study. The subjects performed the PUP exercise with and without ADIM. Surface electromyography was used to collect the electromyography data of the UT, LT, and SA. A scapulometer was used to measure the amount of scapular winging. Results: SA activity was significantly greater and scapular winging significantly lower during the PUP exercise with ADIM than during those without ADIM. Conclusion: PUP exercise with ADIM can be used as an beneficial method to improve SA activation and to reduce the amount of scapular winging in subjects with scapular winging.

Railroad ballast materials tend to degrade due to the increase of ballast abrasion and fracture that results in decreasing the capability of shock absorption, interlocking friction, and the resistance to track irregularity. Therefore, it is necessary to establish a methodology to improve or maintain the structural condition of ballast materials which is in the middle of fouling. This study aimed to investigate the effect of reinforcement on the fouled ballast using ballast stabilizer. Field experimental program was conducted to compare the lateral ballast resistance in case of before and after application of ballast stabilizer. A series of laboratory repetitive load triaxial compression test was then performed to compare the accumulated plastic strain in case of before and after application of ballast stabilizer to the ballast materials having a different level of Fouling Index(FI). In the event of application of ballast stabilizer, the accumulated plastic strain decreased by 41.8 and 28.8 percent, respectively, when the FI was 14 and 21, which appears to indicate the ballast stabilizer is effective for the moderate level fouled ballast materials.

This study was performed to evaluate the type and concentration of TVOC and formaldehyde emitted from asbestos stabilizers, because the stabilizers can be applied on the surface of asbestos contained building materials(ACBM). The emission test of three organic and synthetic resins(OSBS) and five inorganic based stabilizers(IBS) were tested for 7 days. The amount of emission and concentrations of TVOC were measured using GC/FID and GC/MS. In case of formaldehyde, quantitative analysis was carried out using HPLC. The average concentrations of TVOC and formaldehyde of 8 stabilizers were 1.173 mg/m²․h and 0.007 mg/m²․h, respectively. The maximum TVOC concentration among five OSBS was 5.698 mg/m²․h and exceeded the TVOC emission standard(4.0 mg/m²․h) for general building materials. According to the this study results, the applied stabilizer can be role one of pollutant sources like paints, floor tile etc. The emission test has to be tested one of stabilizers efficiency to manage the indoor air quality of building.

Zinc soap and Zn/Ba mixed metal soap were synthesized and PVC plastisol with mixed metal soap and various costabilizers were also synthesized with good structures and characterized by IR and 1H-NMR. The IR spectrums and 1H-NMR spectrums of the synthesized soaps were in very good accordance with the structures proposed by earlier workers. In using phosphite as a costabilizer, TIDP phosphite was shown to be the excellent thermal stabilization effect at the low temperature and TNPP phosphite was shown to be the excellent thermal stabilization effect at the high temperature. In case of antioxidant, it was revealed that antioxidant was not effective in the low temperature thermal stabilization effect while highly effective in the high temperature thermal stability. NaClO4 solution with sorbitol solvent had the best thermal stabilization effect among NaClO4 solution series at low and high temperature.

Background: This study investigated effective posture for gluteus medius rehabilitation training and effects of isometric muscle activity by electrophysiology through EMG while performing dynamic isotonic behavior of weight placed differently on upper limbs. Method: 16 healthy male subjects 20 to 29 years of age volunteered for the study. Lateral stabilizer right gluteus medius activity was assessed using EMG while the right lower extremity maintains single limb support, and the left upper extremity elevation movement maintains 5 seconds without load, 1RM to 1 repetition, 5RM to 5 times, 10RM to 10 times, 5RM and 10RM maintain 5sec. Results: Comparison of the mean value of EMG data showed a statistically more significant difference in upper extremity elevation movement on opposite upper extremity added weight than one that was not added on a single limb weight bearing posture(p>.05). Weight supported side gluteus medius activity for 1RM, 5RM, 10RM weight difference and movement repetition did not differ(p>.05). Comparison in maximum value showed statistically significant differences in not adding weight on upper limb elevation exercise and 1RM, 5RM, 10RM repeated behavior. Elevation behavior and repetition appeared over 70% of MVIC. Conclusion: Unilateral weight bearing stance added weight in the opposite upper limb elevation movement was an indirect exercise to effectively stimulate gluteus medius activity. Applying various added weight will have effective exercise on the early stages of rehabilitation because activity gluteus medius did not differ through added weight.

In this study, partially stabilized zirconia was synthesized using a chemical Y2O3 stabilizer and hydrothermal method. First, YCl3-6H2O and ZrCl2O-8H2O was dissolved in distilled water. Y-TZP (a Y2O3-doped toughened zirconia polycrystalline precursor) was also prepared by conventional co-precipitates in the presence of an excess amount of NH4OH solution under a fixed pH of 12. The Y-TZP precursors were filtered and repeatedly washed with distilled water to remove Cl- ions. ZrO2-Xmol%Y2O3 powder was synthesized by a hydrothermal method using Teflon Vessels at 180˚C for 6 h of optimized condition. The powder added with the Xmol%- Y2O3 (X = 0,1,3,5 mol%) stabilizer of the ZrO2 was synthesized. The crystal phase, particle size, and morphologies were analyzed. Rectangular specimens of 33mm×8mm×3 mm for three-point bend tests were used in the mechanical properties evaluation. A teragonal phase was observed in the samples, which contains more than 3 mol% Y2O3. The 3Y-ZrO2 agglomerated particle size was measured at 7.01μm. The agglomerated particle was clearly observed in the sample of 5 mol % Y2O3-ZrO2, and and the agglomerated particle size was measured at 16.4 um. However, a 20 nm particle was specifically observed by FE-SEM in the sample of 3 mol% Y2O3-ZrO2. The highest bending fracture strength was measured as 321.3 MPa in sample of 3 mol% Y2O3-ZrO2.

본 연구에서는 최소모델영역 연산자를 MT(magnetotelluric) 2차원 역산 알고리듬에 적용하여 역산 해의 대비를 향상시키고자 하였다. 이를 위하여 creeping법에 기초한 최소자승 역산에 최소모델영역 연산자를 수치적으로 유도하여 알고리듬을 구현하였으며, 공간함수로서의 평활화 상수를 도입한 ACB (Active Constraint Balancing) 법을 동시에 적용하여 최소모델영역 연산자를 이용할 때 단점으로 지적되었던 역산 해의 안정성을 향상시켰다. 고립된 단일 이상체 모델에 대한 수치실험을 통하여 MT 역산에 있어서 최소영역 연산자의 효과를 기존의 2차 미분연산자와 비교 분석하여 MT 역산에서의 특징을 고찰하였다. 또한 다중 이상체 모델에 대한 실험을 통하여 Occam 역산과 비교하여 최소모델영역 연산자를 이용한 역산 해의 특징을 비교 분석하였으며 현장 자료에의 적용을 통하여 그 적용성을 살펴보았다.

화학적 첨가제를 이용한 안정처리는 지반의 강도증가 및 변형발생을 제어하기 위한 방법으로 깊은 심도까지 광범위하게 적용되어 지고 있다. 화학적 안정처리의 기본목적은 지반의 강도증가, 압축성 감소, 팽창특성 등을 개선하여 지반의 내구성을 증가시키는 것이며, 최근 들어 환경친화적이며 혼합체의 특성 및 혼합속도를 효율적으로 개선한 다양한 형태의 진보적인 시멘트 혼화재가 개발되고 있다. 본 연구에서는 농어촌도로(농도)의 효율적인 포장공법 개발을 위하여 시멘트혼화재를 활용하는 방안을 연구하였으며, 혼화재 종류 및 배합비에 따른 다짐시험, 일축압축강도시험, 동결융해시험 및 휨강도시험을 실시하였다. 본 연구결과에 따르면, 실트질 원지반토가 점토지반에 비해 강도증가 및 동결융해특성이 우수하며, 액상형 시멘트 혼화재가 분말형태 보다 효과적인 것으로 나타났다. 또한 저배합에서도 고강도의 품질을 발휘하여 농어촌도로 표층 내구성 저하를 개선할 수 있을 것으로 판단된다.

This study was carried out to compare the muscle activities of the shoulder stabilizers between persons with and without winging scapular during push-up plus exercise (adds the scapular protraction to the general push-up exercise). For this study, eleven males with winging scapular and eleven healthy males were recruited. Surface electromyographic (EMG) activity was recorded from the serratus anterior, upper trapezius, lower trapezius, infraspinatus, and pectoralis major while the subjects performed the push-up plus. Each push-up plus was subdivided into three phases according to the elbow position which was measured using the 3-D motion analysis system: elbow flexion (EF), elbow extension (EE), and shoulder protraction phases (SP). Two-way repeated measure ANOVA (phase group) were used for statistical analysis. There was significant phase by group interaction only on the EMG composition ratio of the serratus anterior (p>.05). The EMG composition ratio of the serratus anterior was significantly higher in SP than in either EF or EE however, it was not different between winging scapular and normal groups. For both groups, the EMG composition ratio of upper trapezius, lower trapezius, and pectoralis major was significantly different across the phases of push-up plus, but the infraspinatus EMG composition ratio was not. For both groups, in EF and EE phases, the EMG composition ratio of both pectoralis major and serratus anterior were relatively higher than that of other muscles. However, in both groups, the EMG composition ratio of the serratus anterior became much more predominant than that of the pectoralis major. In addition, infraspinatus activated greater than pectoralis major. These results showed that the push-up plus exercise is effective to selectively strengthen the serratus anterior for both individuals with and without winging scapular, but not equally effective for other shoulder stabilizers.

제주대학교 실습선 아라호에 정착된 능동형 횡동요 감쇠장치의 성능에 관해 연구하기 위하여 33˚00‘.44”N, 125˚59’.88 ”E 위치에서 선박을 정지한 후, 횡동요 감쇠장치를 정지 (Passive A.R.T), 작동 (Active A.R.T)을 했을 때 경사계에 의한 횡동요각 및 종동요각, 풍속계에 의한 풍속의 변화와 그리고 선박이 항해 중에 감쇠장치의 작동을 정지(Passive A.R.T), 작동(Active A.R.T) 했을 때 의 능동형 횡동요 감쇠장치의 성능을 분석한 결과에 대해 요약하면 다음과 같다. 1. 선박이 정지했을 때 횡동요 감쇠장치를 정지, 작동한 경우 횡동요각의 평균진폭 (Average Amplitude of Roll) 은 각각 8.30˚, 4.37˚, 횡동요각의 유의진폭(Significant Amplitude of Roll π1/3)은 각각 10.10˚, 5.30˚으로 나타났다. 2. 선박이 항해 중 일 때에는 횡동요각의 평균진폭 (Average Amplitude of Roll)은 각각 5.01˚, 4.36˚, 횡동요각의 유의진폭 (Significant Amplitude of Roll˚) 은 각각 5.50˚, 5.10˚으로 각각 나타났다. 3. 횡동요 감쇠장치는 선박이 정치했을 때에는 47.5%, 선박이 운항 했을 때는 12.7% 정도의 감쇠 효율을 보여서 정지했을 때 그 효율이 높은 것으로 나타났다. 4. 횡동요 감쇠 장치는 종동요(Pitching)에 대해서는 거의 영향을 미치지 않았다.

Selection of oocyte cryopreservation method is a prerequisite factor for developing an effective bank system. Compared with slow freezing method, the vitrification has various advantages such as avoiding intracellular ice crustal formation. In our previous, we attempted to employ a vitrification method using ethylene glycol and an electron microscope grid for cryopreservation of mouse oocytes. However, A high incidence of spindle and chromosome abnormalities was detected in thawed oocytes after vitrification. We examined whether the addition of a cystoskeleton stabilizer Taxol , to the vitrification solution could promote the post-thawed survival and subsequent development of stored oocytes. More oocytes developed to the 4-cell (44.7% vs. 69.7%), 8-cell (31.8% vs. 64.2%), morula (24.7% vs. 54.3%), and blastocyst (20.3% vs. 49.2%) stages after the addition of Taxol to the cryoprotectant than after no addition. 21 and 26 mouse pups were born after transfer of blastocyst derived from oocytes vitrified without and with Taxol. The addition of Taxol to vitrification solution greatly promoted post-thaw preimplantation development of ICR morose oocytes.tes.

본 연구는 실리콘계 정포제의 특성에 따른 폴리우레탄 폼 지수제의 cell 구조와 흡수량 변화를 알아보기 위하여 6종의 정포제를 사 용하여 폴리우레탄 폼 지수제를 제조하여 FE-SEM으로 분석한 결과 실리콘 정포제의 실록산 주사슬 말단에 PO n개가 결합되어 있는 DC-193, DC-2585, DC-5125, DC-198의 cell 구조는 close cell로 확인이 되었고, 실리콘 정포제의 실록산 주사슬 말단에 EO n개가 결합 되어 있는 DC-5043과 DC-5598은 open cell 구조로 나타났다. 또한 cell 구조 변화에 따른 흡수량 에서는 close cell의 크기가 가장 세밀하고 균일한 DC-193의 흡수량이 가장 적게 나타나 내수성이 가장 우수한 것으로 나타났으며 open cell의 크기가 가장 크게 형성된 DC-5043의 흡수량이 가 장 많은 것으로 나타났다. 이들의 방수성능을 콘크리트 구조물을 모사하여 시험한 결과 누수가 없음을 확인하였다.

거친 바다를 운항하는 선박의 경우 횡 동요로 인해 선박 내의 장비운영 문제 및 탑승객들에게 큰 불편함을 초래한다. 따라서 횡동요 감쇠를 위한 목적으로 빌지 킬, 핀 안정기, 자이로스코프, ART(Anti-Rolling Tank), 타, 플랩 등 다양한 횡 동요 감쇠장치들이 사용되고 있다. 콴다효과는 콴다제트가 곡면의 표면을 따라 흐르며 주위 유동의 순환을 증가시켜 양력을 효과적으로 발생시키는 방법으로 핀의 양력성능을 향상시킬 수 있다. 본 연구에서는 모형시험 및 수치계산을 통해 콴다효과를 적용한 고정식 핀 안정기의 사용가능성을 검토하였다. 그 결과 받음각이 0˚에서, 제트모멘텀을 Cj = 0.25 만큼 공급할 때, 기준 핀의 최대 작동각(26˚)에서 발생되는 양력과 동일하게 발생되는 것으로 나타났다. 즉 받음각을 변화시키는 기존의 핀 안정기와 달리 받음각을 고정하고, 콴다효과를 통한 제트유동제어만으로 선박의 횡 동요를 능동적으로 제어 할 수 있을 것으로 보인다.