• 정보보호학회논문지
• /
• 제33권2호
• /
• pp.319-323
• /
• 2023

프로세스 내부 격리(Intra-process Isolation)에서 파일 디스크립터는 메모리 이외에 또 다른 공격 벡터로써 작용한다. 공격자는 파일 디스크립터를 변조함으로 주어진 권한 이상의 파일에 읽거나 쓰는 방식을 통해 격리된 환경을 벗어날 수 있다. 본 논문에서는 ARM 아키텍처의 하드웨어 보안 기술인 PA(Pointer Authentication) 기반의 경량화된 새로운 파일 디스크립터의 권한 관리 시스템을 제시한다. 우리의 무결성 보장 기법은 리눅스 커널 모듈의 형태로 제작되었으며 5% 정도의 오버헤드만으로 파일 디스크립터에 대한 권한 관리를 수행하였다.

• 한국의류학회지
• /
• 제46권2호
• /
• pp.310-320
• /
• 2022

This study aimed to ascertain the most efficient level of compression to be applied on a particular area along the upper extremities whilst developing functionality to prevent musculoskeletal disorders among workers who frequently use their arms. The compression areas were divided into upper arm, forearm, and wrist. The compression levels were applied using three types of bands. Comparisons on these bands' usability were based on evaluations of recorded brainwaves and subjective sensation response. Nine men in their twenties were selected for the experiment. The results revealed that when compression was applied, the left and right occipital lobes, plus the parietal lobe, were activated. Also, the alpha wave activity tended to increase, thereby exemplifying the compression's positive effects. The most physiologically efficient and subjectively preferred compression levels were 1.3 and 2.6 kPa for the upper arm and wrist. Furthermore, the compression level at the forearm should be at least 2.0 kPa.

• 한국의류산업학회지
• /
• 제21권4호
• /
• pp.488-496
• /
• 2019

This study investigated if the proper pressure level on the wrist tendon area and muscle area of the lower arm are within the same range by examining the responses of blood flow and subjective evaluation. Subjects consisted of 18 males in their 20s, and the experimental bands were custom-made by applying size measurements of each subject. In the experiment, a total of 5 steps were selected by reducing 10 (Step 1) to 50 (Step 5)% from the original body size in the circumferential direction. Blood flow was measured with a sensor attached to the tip of the finger inside the right hand while sitting in a chair for 15 minutes. Blood velocity began to increase (0.82 kPa) when the wrist circumference around tendon area was reduced by 20% (Step 2) and reached its maximum (1.72 kPa) at Step 4. However, the preferred subjective pressure was 1.36 kPa, which was less than the maximum pressure value of 1.72 kPa for Step 4. Blood velocity began to increase when pressure on the muscle area was 1.38 kPa and reached its maximum at 2.16 kPa; however, the most preferred clothing pressure was 1.71 kPa. The results of this study showed that the appropriate pressure level was higher in the muscle area than in the wrist tendon of the lower arm and indicated that graduated compression is favorable.

• 한국전문물리치료학회지
• /
• 제23권2호
• /
• pp.84-92
• /
• 2016

Background: Strengthening the supraspinatus is an important aspect of a rehabilitation program for subacromial impingement and tendinopathy. Many authors recommended empty-can (EC), full-can (FC), and prone full-can (PFC) exercises to strengthen the supraspinatus. However, no ultrasonography study has yet investigated supraspinatus muscle architecture (muscle thickness; MT, pennation angle; PA, fiber bundle length; FBL) in relation to supraspinatus strengthening exercises. Objects: The purpose of this study was to compare the architecture (MT, PA, and FBL) of the supraspinatus muscle during three different types of exercises (EC, FC, and PFC) using diagnostic ultrasound. Methods: Participants performed three different exercises: (A) EC; the arm was maintained at $60^{\circ}$ abduction with full internal rotation in the sitting position, (B) FC; the arm was maintained at $60^{\circ}$ abduction with full external rotation in the sitting position, and (C) PFC; the arm was maintained at $60^{\circ}$ abduction with full external rotation in the prone position. Ultrasonography was used to measure the MT, PA and FBL of the supraspinatus. One-way repeated analysis of variance with Bonferroni's post-hoc test was used to compare between the three exercises and the initial position of each exercise. Results: Compared with each initial position, the FC exercise showed the greatest mean difference in muscle architecture properties and the PFC exercise showed the least mean difference. Conclusion: The findings suggest that the FC exercise position may have an advantage in increasing the amount of contractile tissue or producing muscle power and the PFC exercise position may be useful in a rehabilitation program because it offers the advantage of maintaining the muscle architecture properties.

• 센서학회지
• /
• 제5권6호
• /
• pp.1-6
• /
• 1996

외부 침입자를 감지하기 위한 높은 감도의 실질적인 매설형 광섬유 센서의 제작에 관하여 논의하였으며, 광섬유로 구성된 마이켈슨 간섭계 센서를 이용하려 본 실험을 수행하였다. 외부에서 인가된 무게와 위상변화 사이의 관계는 선형적이었고, 감지 아암을 모래 표면으로부터 8 인치 아래로 매설하였을 때, 센서 출력파형의 위상이 반주기가 이동하는데 필요한 압력과 길이의 곱은 약 $1.09\;kPa{\cdot}m$이였다. 본 실험으로부터 광섬유 센서의 감도는 매설된 광섬유 위를 걸어가는 사람과 그 위를 지나가는 수레 등을 감지하기에 충분히 높은 감도를 가진다는 결론을 얻을 수 있었다.

• 한국의류학회지
• /
• 제46권4호
• /
• pp.613-623
• /
• 2022

This study developed a functional prototype jacket designed to reduce loads on the upper extremities of workers performing repetitive motions in the same posture for extended periods of time. Dynamic taping lines were applied to the upper extremities, and three dimensional (3D) supporters were inserted in the abdomen and back waist areas corresponding to the core muscles. Clothing pressure on the upper-extremity dynamic taping lines was set to two levels (proto P1 and proto P2), and the 3D supporters were designed in three types (proto FW, proto FW/BW, proto FW/BW/BBX). According to the subjective pressure perceived on each part of the upper extremities, the level proto P1 pressure was preferred. The proto FW/BW/BBX 3D supporter was rated as excellent, and the perceived pressure was ranked as satisfactory. The prototype jacket performed upper-extremity load reduction when the upper-extremity clothing-pressure level was set to 1.8 kPa, 2.1 kPa, and 2.4 kPa on the upper arm, forearm, and wrist regions, respectively, and when 3D supporters were installed in the abdomen and back of the waist with the addition of a back band.

• 국제물리치료학회지
• /
• 제10권2호
• /
• pp.1803-1809
• /
• 2019

Background: Cervical mobilization has been applied mainly for the improvement of arm and neck movements and pain reduction, and little research has been done to improve the executive function. Since this kind of so-called mechanical neck pain is one of most common symptoms, there are controversial issues about this with spine alignment. Posteroanterior (PA) mobilization from the Maitland concept is a process of examination, assessment, and treatment of neuromusculoskeletal disorder by manipulative physical therapy. Objective: To examine the short-term benefits of mobilization for patients with non-specific neck pain. Design: Dual-group Pretest-Posttest Design from the Quasi-Experimental research Methods: Fourteen participants (male 8, female 6; 20's of their age) with non-specific neck pains which are distributed all the unilateral or bilateral body side were recruited. Participants were categorized to Neck Pain with Movement Coordination Impairments (NPMCI) and Neck Pain with Mobility Deficits (NPMD) groups according to the results of physical examination. Professional physical therapist who has over 15-years-of clinical experience applicated manipulative therapy for the neck pain, an occupational therapist only conducted evaluations; K-NDI (Korean version of the Neck Disability Index), VAS (Visual Analog Scale), BDS-K (Korean version of Behavioral Dyscontrol Scale) for decreasing possible adverse effects; there were no person who reported other symptoms followed 4 weeks from the trial. Results: In the NPMCI group, data analysis indicated statistical differences between the PA mobilization interventions in NDI and BDS-K; even though, pain was reduced in VAS, this is not a significantly differ. In the NPMD group, data analysis represented statistical differences between the PA mobilization interventions in NDI, VAS and BDS-K; the scores were represented to be increased or the pain got relief. Conclusions: PA mobilization techniques according to Maitland concept have beneficial effects in patients with neck pain and other clinical positive effects which included neck disability, pain itself and motor function of upper extremity.

• The Journal of the Acoustical Society of Korea
• /
• 제21권1E호
• /
• pp.25-30
• /
• 2002

We report on the development of a fiber optic hydrophone consists of a sensing Michelson interferometer and a compensating Mach-Zehnder interferometer for optical path length compensation. The double interferometer configuration has the following advantages: the hydrophone can be made more small; a laser source with a relatively short coherence length can be used; and the compensating interferometer can be located near the signal processing electronics, far away from the sensing interferometer and noise introduced by reference arm can be greatly reduced. The performance of the hydrophone is evaluated experimentally by immersing the sensing interferometer in a water tank to detect underwater acoustic signals generated by an acoustic wave projector. Experimental results show that over the frequency range of 1 to 4 kHz, the hydrophone has an almost flat response with an average normalized sensitivity of -302 dB re 1/ μ Pa.

• 한국방사선학회논문지
• /
• 제7권4호
• /
• pp.271-275
• /
• 2013

어깨뼈 검사는 일상생활, 스포츠 활동 시에 어깨관절의 후측부나, 후외측부에 강한 외력이 가해서 발생하는 직접외상에 의한 경우와 상완부에 주로 외전, 신전, 외회전력이 가해져 어깨관절 탈구 등 병변의 유무를 관찰하는데 유용하게 사용되고 있다. 본 연구의 목적은 어깨관절 후전사방향촬영(shoulder PA oblique projection, scapula Y-view)의 촬영각도에 따른 영상의 왜곡을 방지하고 방사선학적 진단에 가장 유용한 촬영 각도를 알아보고자 하였다. 어깨뼈체부와 봉우리(acromion) 및 부리돌기(coracoid process)는 Y자를 이루게 되는데 $10^{\circ}$에서는 어깨뼈와 봉우리사이의 각도가 협착되어 나타나고, $20^{\circ}{\sim}25^{\circ}$에서는 Y자에 위팔뼈머리가 겹쳐 보이며, 어깨관절과의 위치도 적절해 보였다. $35^{\circ}$에서는 위팔뼈머리가 Y자에 겹쳐 보이지만, 위팔뼈머리와 어깨관절이 왜곡되어 보였다. 환자체위는 $45^{\circ}$ 거상시킬 때 가장 적합한 측면상을 관찰되며, 봉우리(acromion) 및 부리돌기(coracoid process)도 Y 자를 이루었다.

• 한국염색가공학회지
• /
• 제33권2호
• /
• pp.87-95
• /
• 2021

In this study, the application of a medical compression sleeve of Moisture Responded Transformable(MRT) fibers to the treatment of lymphedema after surgery in breast cancer patients was investigated. MRT fibers were manufactured with PET and Nylon6 bi-component cross-section yarns, and compression sleeves of sleeves 1, 2, 3, and 4 were knitted in order of size, and then the physical properties and clinical tests were evaluated. As a result, the pressure of compression sleeve in wrinkle was the lowest in sleeve 1 with 3.81 kPa, and the highest in sleeve 4 with 5.22 kPa. Elastic recovery rate is that all parts except the top of the sleeve 1 exhibited 100%. The air permeability was good at 12.1 ~ 16.1 cm³/cm²/sec, and peeling was also comparatively excellent as grade 3. In addition, the weight of the compression sleeves 1, 2, and 3 decreased as 18.3 ~ 23.0 g/m² depend on size, while the compared sample was heavier with 17.39 ~ 32.61 g/m². In lymphoscintigraphy test, it was confirmed that the function of remaining lymph node was good in all patients. Although there were no differences between samples in skin irritation and tightness in wearing comfort, the manufactured sleeves showed better fit, lightness, fashion and breathability than the comparable sleeves.