• Journal of Advanced Marine Engineering and Technology
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• 제7권1호
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• pp.34-39
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• 1983

Development of modern internal combustion engine requires more precise indicator. In the case of strain gage-strain tube type indicator, thermal expansion of the indicator's fixed part makes zero-shift in spite of water cooling. Therefore, the authors analyzed the cause of zero-shift phenomenon on strain gage-strain tube type indicator and proposed a new device to compensate the zero-shift of indicator by electrical method without detoriorating the dynamic charcteristic. As the results, we found that the zero-shift is varied linearlly according to temperature variation of the indicator's fixed part and appling a new device, we can improve the zero-shift of indicator about 0.63% (0.63 kg/$cm^2$) of full scale, though we got 10% of it without the device at the cylinder head operating temperature (c.a. $200^{\circ}C$).

• ETRI Journal
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• 제43권3호
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• pp.427-435
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• 2021

Data filtering is an essential task for improving the energy efficiency of radiofrequency identification (RFID) networks. Among various energy-efficient approaches, clustering-based data filtering is considered to be the most effective solution because data from cluster members can be filtered at cluster heads before being sent to base stations. However, this approach quickly depletes the energy of cluster heads. Furthermore, most previous studies have assumed that readers are fixed and interrogate mobile tags in a workspace. However, there are several applications in which readers are mobile and interrogate fixed tags in a specific area. This article proposes a model for dynamic clustering-based data filtering (DCDF) in mobile RFID networks, where mobile readers are re-clustered periodically and the cluster head role is rotated among the members of each cluster. Simulation results show that DCDF is effective in terms of balancing energy consumption among readers and prolonging the lifetime of the mobile RFID networks.

• Journal of Oral Medicine and Pain
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• 제23권4호
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• pp.457-473
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• 1998

This study was performed to investigate the morophological and positional correlation between the upper cervical vertebra, the oral structures and the pharyngeal tissues, and the correlation of these anatomical structures with dental features, such as teeth wear area nad tooth contact status, etc. Seventy patients with temporamandibular disorders and sixty three dental students without any signs and symptoms in head and neck region were selected for this study. All they had natural dentition without any fixed and removable protheses. Teeth wear area and arch width wre measured from the upper dental cast, tooth contact status were observed by T-Scan system$^\textregistered$ and four cephaloradiograpohs were taken from four head postures, namely, natural(NHP), forward(FHP), upward(UHP), and downward head postiure(DHP). 22 cephalometric items were measured on the films and the data were processed with SAS statistical program. The result of this study were as follows : 1. In normal group, angle of cervical vertebra tangent and of between hard and soft palate were broader in female subjects than those in male subjacets, but distance from subocciput to axis, size of soft palate, and pharyngeal space width were larger in male subjects. 2. In normal group with natural head posture, the items correlated each others from the three anatomical regions were distance between first nad second vertebra in posterior part, distance from the lingual surface of lower anterior teeth to anterior surface of soft palate, and distance from the hyoid bone to third vertebra. 3. Three set of items showed significant correlation each other in the four head postures in normal group. First set was the angle between hard and soft palate and the idstance from subocciput to posterior arch of first vertebra, second set was the distance between first and second vertebra in posterior part and the teeth wear area, third set was number and force of tooth contact and length of soft palate and distance from anterior tip of hyoid bone to mandibular plane.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.133-136
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• 2012

본 논문은 무안경 3D 디스플레이 제품의 품질을 향상시키기 위한 여러 가지 효과적인 방법을 구축하는데 목적을 두었다. 무안경 제품은 기존의 안경 방식에 비하여 3D의 depth 화질 품질이 떨어졌고, 특정 거리, 위치에서만 볼 수 있는 단점이 있어, 이를 보완하고자 Head Tracking 기술 및 영상 배치알고리즘 등 여러 가지 기술을 적용하여 기존 system의 단점을 보완하였다. 본 논문은 3D 무안경 구현 방식 중 Parallax Barrier의 3D 품질 향상을 위한 Head Tracking을 통한 사용자의 위치 파악, 영상의 재배치 기술 및 Crosstalk 개선 방법에 대해 보고합니다.

• 대한정형외과학회지
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• 제56권5호
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• pp.427-432
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• 2021

원위 요척 관절의 전방 탈구 치료가 지연된 경우에는 수근부 통증과 전완의 회전 운동의 제한이 동반되어 결국 구제술이 필요한 퇴행성 관절염이 발생할 수 있다. 24세 남자가 요골 간부 골절 수술 후 통증과 회전 운동 제한으로 내원하였다. 금속판으로 고정된 요골의 간부에서 7도의 전방 각형성이 관찰되었으며 척골 두가 전방으로 탈구되어 회외전에서 결손부가 요골의 S자 절흔 전방 경계에 걸려 탈구가 지속되는 소견이 관찰되었다. 부정 유합된 요골의 교정의 절골술과 척골 두 골결손 근위부의 골을 원위 결손 부위로 이동시키는 절골술을 시행하여 원위 요척 관절이 전완의 회전에 안정적으로 정복이 유지되도록 하였다. 수술 후 19개월에 전완 회전 운동 범위와 통증이 개선된 것을 확인하였다.

• 대한통합의학회지
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• 제11권3호
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• pp.195-204
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• 2023

Purpose : This study applied general training (control group) or cranio-cervical flexor training (experimental group) using a pressure biofeedback unit along with general training for 4 weeks to secondary school teachers with moderate to severe neck pain and forward head posture. After that, we tried to compare the effects through differences in neck pain intensity (using numberical rating scale), functional performance (using neck disability index), and cranio-vertebral angle change. Methods : All 50 subjects were randomly assigned to either the "experimental group (n= 25)" or the "control group (n= 25)", and the measurements were evaluated in the same way before the intervention (baseline) and after the intervention (4 weeks). During the intervention period, the subject visited the physiotherapy center and made a reservation three times a week at a fixed time as much as possible, and each training session was thoroughly conducted under the 1:1 guidance of the therapist in charge so that the correct movement and number of times could be performed without compensatory action. Results : As a result of the homogeneity analysis on the general characteristics of the subjects, there were no significant differences between the groups in all variables (p>.05). Compared to the "control group", the "experimental group" showed significant improvement after intervention in all measured variables of neck pain intensity, functional performance, and cranial-vertebral angle (p<.05). Conclusion : For secondary school teachers with forward head accompanied by neck pain, cranio-cervical flexor training using a compression biofeedback unit is an excellent method to show superior pain reduction and functional performance improvement compared to general training alone. In addition, it can be presented as a more effective intervention method that can promote recovery of forward head posture, which is an essential element of the solution.

• Anatomy and Cell Biology
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• 제56권1호
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• pp.39-45
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• 2023

Fixation of radial head fracture with minimally invasive posterior approach remains a significant challenge. The aim of this study was to determine the feasibility of trans-anconeus posterior elbow approach and to observe lateral ulnar collateral ligament (LUCL) in extended elbows. This cadaveric study was performed in twenty upper limbs of fresh fixed adult male cadavers. An oblique incision was made in the middle segment of anconeus until the lateral ligament complex and the joint capsule had been revealed. A deep dissection was explored to observe the anatomical relationship of the LUCL to the anconeus. Measurements of the LUCL were recorded while the elbow was fully extended. The mean distance between the edge of the radial head and the proximal insertion of the LUCL was 13.3 mm (11.5-16.2 mm); the mean distance between the edge of the radial head and the distal insertion of the LUCL was 20.9 mm (19.2-23.4 mm); the distance between the edge of the radial head and the distal edge of the annular ligament was 11.2 mm (8.22-11.7 mm). By estimate correlation of the previous measurements, the direct and accessible way to expose the posterolateral articular capsule of the elbow joint was through a window in medial 2/3 of the middle segment of anconeus muscle. These trans-anconeus approach is useful. It provides good visualization, facilitates applying the implants, and lessens the risk of radial nerve injury. Awareness of the anatomy is mandatory to avoid injury of LUCL.

• 대한두경부종양학회지
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• 제17권2호
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• pp.169-173
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• 2001

Objectives: The p53 tumor suppressor gene encodes a nuclear transcription factor that is critical regulator of cell growth and proliferation through its action in cell-cycle checkpoint control. The wide variety of stressful stmuli which include DNA damage, hypoxia, heat shock, metabolic changes activate the p53 protein, which in turn drives a series of events that culminate either in cell cycle arrest or apoptosis. Mutations of the p53 gene is the most common genetic alteration in human cancer. This gene is altered in approximately 40-60% of head and neck cancers. Whereas the wild-type form of the p53 protein plays a central role in cell-cycle control in response to DNA damage, most of the mutant forms are unable to do so. The high levels of p53 protein expression in tissues are related to the increased cellular proliferative activity and may be associated with the poor clinical outcome. To determine whether the expression of the p53 protein has prognostic significance and is associated with patterns of treatment failure in head and neck squamous cell carcinoma (HNSCC), We analyzed p53 overexpression in 40 cases of HNSCC. Materials and Methods: Immunohistochemical analysis with a monoclonal antibody (DO7) specific for p53 protein was used to detect expression of the protein in formalin-fixed, paraffin-embedded tumor samples from 40 HNSCC. We evaluated p53 protein expression and analyzed the relationship between the p53 overexpression and age, sex, primary tumor site, stage, survival rate, recurrence. All reported P values resulted from two-sided statistical tests. Results: Overexpression of p53 was detected in 20 cases(50%) among 40 cases of HNSCC. The p53 overexpression was not associated with age, sex, primary tumor site, stage, recurrence and survival rate. Conclusions: In our results, p53 was not significant prognostic factor in HNSCC. Based on many previous studies, It is evident that p53 has a certain role in tumorigenesis of HNSCC. So, the further study is needed to evaluate the prognostic significance of p53 in HNSCC.

• 대한치과의사협회지
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• 제19권11호통권150호
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• pp.975-979
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• 1981

In May 1981, the author placed Free Design Blade Implant into a 24-year old female patient with missing teeth of lower left molars, who did not want a removable partial denture. The bone available was good enough and in apparent general good health. The implant bridge was mad by four units, from 1st premolar to implant head, which is now in good esthetics and function.

• 한국광학회지
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• 제29권1호
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• pp.19-27
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• 2018

일반적으로 광학계의 물체거리가 변하면 배율이 변하게 된다. 본 논문에서는 일반적인 이중 가우스(double-Gauss) 형태의 광학계에서 조리개를 기준으로 조리개 앞쪽에 위치한 렌즈군과 조리개 뒷쪽 렌즈군을 광축 방향으로 독립적으로 평행하게 이동하여 물체거리에 따라 배율과 상면이 고정되는 광학계를 제안하고 설계하였다. 이러한 광학계는 전방시현장치(head-up display, HUD), 두부장착디스플레이(head-mounted display, HMD) 등의 투사 광학계에 물체거리의 변화에 따라 상 크기가 변화하지 않도록 하여 전방시현장치 또는 두부장착디스플레이에서 초점 조절(focusing) 시에 화각이 변하지 않도록 하였다. 또한 반도체 칩과 IC 회로기판을 연결하는 와이어(wire)의 상태를 검사하는 과정에서 검사장비가 위 아래로 움직여서 물체거리가 변해도 광학계의 배율이 변하지 않도록 하여 고속검사가 가능할 수 있도록 별도 영상 처리를 시스템적으로 생략할 수 있었다. 본 논문에서 가우스 괄호법(Gaussian bracket method)을 이용하여 원하는 사양을 만족하도록 각 군의 이동량을 구해서 배율과 상면이 고정되도록 하였다. 초기 설계를 진행한 후, 최적화는 광학 설계 프로그램인 시놉시스(Synopsys)를 사용하였다.