Earticle

Purpose: The rolling pattern is a crucial part of human development and movement, utilized in assessing movement development in children and evaluating the physical abilities of adults. This pattern is essential for enhancing various joint movements and balance, serving as a significant performance element for athletes such as unilateral sports athletes. It can be a vital tool for injury prevention and identifying functional impairments, even among athletes. Methods: The rolling test helps differentiate localized and overall functional limitations. To conduct an accurate evaluation, it requires flexibility, core stability, controlled movement, and adequate limb/trunk range. It assesses thoracic/lumbar rotation, core control, and limb rotation. Prior to the test, examinations such as thoracic rotation, pelvic rotation, and pelvic tilt are necessary. Moreover, the rolling test should be evaluated in conjunction with selective functional movement assessment (TPI medical2). Before intervening in rolling issues, they're broadly divided into Mobility Dysfunction (MD) and Stability Motor Control Dysfunction (SMCD). A 3-step process called 3R (Reset, Reinforce, Retrain) is used for resolution, enhanced through corrective exercises. These exercises apply two feedback types: Facilitate, easing movement difficulty, and Challenge, engaging other body parts for core posture adjustments. Results: A 15-year experienced, right-handed professional golfer in his 20s, standing at 188 cm and weighing 90 kg, addressed his asymmetry issues. After the evaluation, corrective exercises for pelvic tilting, rotation, and rolling were conducted, resulting in an improvement in clubhead speed from 106 mph to 110 mph. This led to enhancements in upper and lower body rolling and improvements in thoracic and pelvic examinations. These outcomes suggest an improvement in the participant's swing mechanics. Conclusion: Athletes may suffer imbalances and injuries due to biased movements and rotations. Unilateral sports athletes, in particular, are prone to spinal injuries as a result of these issues. Symmetry is crucial for healthy functionality, and the rolling pattern aids in restoring this symmetry. Additionally, evaluating symmetry between the upper and lower body, as well as left-right balance, is crucial.

The new numerical procedure for hydroplaning has been developed by considering the following three important factors; fluid/structure interaction, tire rolling, and practical tread pattern. The tire was analyzed by FEM with Lagrangian formulation and the fluid is analyzed by FVM with Eulerian formulation. Since the tire and the fluid are modeled separately and their coupling is automatically computed by the coupling element, the fluid/structure interaction of the complex geometry such as the tire with the tread pattern can be analyzed practically. We verified the predictability of the hydroplaning simulation in the different parameters such as the water flow, the velocity dependence of hydroplaning, and the effect of the tread pattern on hydroplaning. In order to predict the streamline in the contact patch, the procedure of the global-local analysis was developed. Since the streamline could be predicted by this technology, we could develop the new pattern in a short period based on the principle; "make the stream line smooth".

The force and moment simulation of a steady-state rolling tire taking the effect of tread pattern into account is described using a steady-state transport method with ABAQUS. Tread meshes can not fully consider a tread pattern because detailed tread meshes are not allowed in the steady-state transport method. Therefore, the tread elements are modeled to have orthotropic property instead of isotropic property. The force and moment simulation has been carried out for the cases of both isotropic and orthotropic properties of tread elements. Both cases of simulation results are then compared with the experimental results. It is verified that the orthotropic case is in a better agreement with the experimental result than the isotropic case. Angle effects of tread pattern have been studied by changing the orientation angle of orthotropic property of tread. It is shown that the groove angle in the tread shoulder region has a more effect on force and moment of a tire than that in the tread center region.

The goal of this treatise is to clear up the chronology of rolling cloud pattern roof-end tiles of Koguryo. For this, I classified the rolling cloud pattern roof-end tiles of Koguryo on the basis of change and combination of individual design elements like the number of division, the number of dividing line, design in the border, representation mode of introvert cres-cent-shaped line. Focusing on the combination of design elements on the surface of roof-end tile, the rolling cloud pattern roof-end tiles of Koguryo has two patterns : (1) dividing line(one line) + no successive triangle pattern in the border + characters in introvert cres-centshaped line + dividing line no reach with the border (2) dividing line(three lines) + successive triangle pattern in the border + no characters in introvert cres-cent-shaped line + dividing line reach with the border. But in the stage of transition from former to latter we can find the mixed pattern of both and also four dividing lines roof-end tiles which is new pattern derived from eight dividing lines roof-end tiles. In my opinion, the main factor that effected changes on design patterns like these is time. On the assumption, I classified the rolling cloud pattern roof-end tile of Koguryo into three types. I make sure that type Ⅰ, the basic form of the rolling cloud pattern roof-end tiles of Koguryo, transferred to type Ⅱ when a certain changes on design elements had been occurred. We can discern big changes on design elements in type Ⅱ: dividing line add up two, characters in introvert cres-cent-shaped line, successive triangle pattern in the border, appearance of four dividing line roof-end tiles. Therefore in type Ⅱ we can see the tendency of secession from traditional manner of production of the rolling cloud pattern roof-end tiles. In type Ⅱ, the sexagenary cycles like“ the year of Eulmyo(355)”, “the year of Jungsa(357)”are carved in relief. If we accept their correctness, type Ⅱ was the new mode which was in fashion for a short period in the middle of 4th century. As type Ⅱ is estimated to be prevailed in the middle of 4th century, it is reasonable that type Ⅰ was used before the middle of 4th century. The proof of this assumption is the name of an era and the sexagenary cycle written in type Ⅰ roof-end tiles. The name of an era and the sexagenary cycle written in type Ⅰ“the 4th year of Taenyung”,“ the year of Gichuk”and “the year of Musul”were estimated each A. D. 325, 329 and 338. Accordingly type Ⅰ can be estimated to be prevailed between the beginning and the middle of 4th century. Comparison with type Ⅰ and Ⅱ, type Ⅲ which shows wide range of transformations of individual design elements is deviated from basic pattern of the rolling cloud pattern roof-end tiles. As type Ⅲ appeared in the transition period of type Ⅱ, if we allow the chronology of type Ⅱ, type Ⅲ can be estimated to be used after the middle of 4th century. It was after the middle of 4th century that not only rolling cloud pattern roof-end tiles but also lotus design roof-end tiles appeared that the huge changes in the mode of Koguryo roof-end tiles took place. So it can be assumed that emergence of lotus design roof-end tile affected on disappearance of rolling cloud pattern roof-end tiles. As the beginning of lotus design roof-end tiles is assumed between the middle and latter of 4th century, type Ⅲ can be chronologized, considering the possibility of coexistence of both, between the middle and latter of 4th century.

중국 길림성 집안 지역에서 출토된 4세기 초~중반의 卷雲文 와당에는 銘文이 새겨진 경우가 많다. 실물 자료에 대한 접근의 어려움 때문에 중국 학자들의 판독안에 크게 의존하는 경향이 있는데, 한국 학계에서도 보다 적극적으로 독자적인 판독 작업을 수행할 필요가 있다. 그간 공개된 사진과 탁본들을 이용하여 판독 작업을 수행한 결과 기존 판독의 오류를 일부 교정할 수 있었다. 대표적인 것이 己丑年 와당의 명문이다. 기존의 판독안은 판독 순서에 규칙성이 없었고, 일부 글자는 판독하지 못하였다. 기존에 잘못 판독하였던 ‘巴’와 ‘領’이라는 글자를 새로 읽어냈고, 글자가 시계 반대 방향으로 순서대로 배열되어 있어 문장을 형성하고 있다는 사실도 밝혀냈다. 그 외에도 몇 개의 와당에서 글자와 판독 순서를 바로잡았다. 고구려에서 가장 오래된 명문 와당으로 ‘태령 4년’명(326) 와당을 꼽아 왔다. 하지만 2001년 제2소학교에서 출토된 ‘甲戌’명 와당을 주목할 필요가 있다. 와당의 형식을 통해 보았을 때 ‘갑술’명 와당은 314년에 제작된 것으로 보인다. 또한 남문리에서 출토된 ‘大吉’명 와당은 제작 기년이 ‘▨申’년인데, 이는 壬申年(312)일 가능성이 높다. 집안 지역에서 출토된 권운문 와당은 명문의 배열 형태에 따라 유형화하는 것이 가능하다. 이에 따라 A·B·C·D의 4개 유형을 설정하였다. A 유형은 다시 A-1형·A-2형·A-3형으로 세분할 수 있다. 이중 A-1형은 중심의 글자를 먼저 읽고, 1시 방향에서부터 시계 방향으로 4글자를 읽은 후, 다시 11시 방향으로 이동하여 이번에는 시계 반대 방향으로 4글자를 읽도록 문장이 배열되어 있는 형태이다. 가장 이른 시기에 등장하여 다양한 제작 주체에 의해 만들어진 유형으로 주목된다.

The temperature distribution of steady state rolling tires with detailed tread blocks is numerically predicted using the three dimensional full patterned tire model. A three dimensional periodic patterned tire model is constructed by copying 1-sector mesh in the circumferential direction. Using the static tire contact analysis, the strain cycles during one revolution are approximated with the strains at Guassian points of the elements which are sector-wise repeated within the same circular ring of elements, by neglecting the tire rolling effect. Based upon the multi-axial fatigue theory, the maximum principal strain is used to represent the combined effect of six strain components on the hysteretic loss. In the following, the deformation due to the inflation and vertical load is calculated using ABAQUS. Then heat generation rate in each element is calculated using an in-house code. Lastly, temperature distribution is calculated using ABAQUS again. Through the numerical experiments, the validity of the proposed prediction method is examined by comparing with the experiment and the temperature distribution of a patterned tire model is compared with those of the main-grooved simple tire model.