• 한국언어정보학회지:언어와정보
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• 제9권2호
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• pp.69-83
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• 2005

This paper discusses the distribution of a null complementizer C, as opposed to an overt counterpart 'that', presenting empirical support both for and against the PF-merge analysis of C proposed by Boscovic and Lasnik (2003, henceafter B&L) who in turn attribute to the proposal in Pesetsky (1992) and Halle & Marantz (1993). In Section I, as a background, I discuss B&L's proposal that a null complementizer C is a PF-affix which undergoes a PF-merger operation at the PF component. In Section 2, after a brief sketch of the distribution of a null C mostly in bare-relatives, I explore the possibility of extending B&L's analysis to accomodate the null C's in the bare-relative constructions. In Section 3, I argue that despite some empirical difficulties, B&L's analysis of a null C as a PF-affix can still be maintained, if Adverb Fronting is an operation to Spec-C position. Furthermore, I propose a rule - PF Spell-Out Constraint - to account for the C-trace (i.e. that-trace) effect in relative constructions. With the PF Spell-Out Constraint and B&L's PF-merge account, the distribution of a null C can better be analyzed.

• 비교문화연구
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• 제23권
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• pp.351-382
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• 2011

This paper aims to compare systems and questions between Chinese I in the Korea National Scholastic Aptitude Test(abbreviated by KNSAT) and Chinese with Listening in the SAT. In the beginning, we compared KNSAT and SAT, and then focused our attention on Chinese I in KNSAT and Chinese with Listening in SAT in terms of assessment purposes, sections, ranges, questions. Through the research, the following results were obtained: Firstly, compared KNSAT with SAT, it is found that Chinese I is less important in KNSAT than Chinese with Listening in SAT. Chinese I belongs to one of the second foreign languages section, and it is placed under common rule of its section. However, Chinese with Listening is similar to Chinese I in that it also belongs to one of the languages section, but it keeps under its control, so it has its own system e.g. purpose, range etc.. Next, compared Chinese I with Chinese with Listening, in the matter of purposes of them, Chinese I is less explicit and less concrete to explain it than Chinese with Listening, and in respect of sections of them, the sections of Chinese I are leaning more toward language materials contrary to Chinese with Listening leaning more toward language functions. And in terms of ranges of them, Chinese I is limited to Basic vocabulary and Examples of communicative function in curriculum of Chinese I, but Chinese with Listening has not any limit on the ranges of questions. Lastly, with regard to questions of them, Chinese I has more tendency toward assessing knowledge of Chinese, on the contrary, Chinese with Listening has more tendency toward assessing performance of it.

• 한국정밀공학회지
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• 제19권8호
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• pp.63-70
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• 2002

In end milling process, the undeformed chip section area and cutting forces vary periodically with phase change of the tool. However the real undeformed chip section area deviates from the geometrically ideal one owing to cutter runout and tool shape error. In this study, a method of estimating the real undeformed chip section area which reflects cutter runout and tool shape error was presented in up end milling process using measured cutting forces. The average specific cutting resistance, Ka is defined as the main cutting force component divided by the modified chip section area. Ka value becomes smaller as the helix angle increases from $30^circC \;to\;40\circC$. But it becomes larger as the helix angle increases from $40^\circ$to 50 . On one hand, the Ka value shows a tendency to decrease with increase of the modified chip section area and this tendency becomes distinct with smaller helix angle.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.826-830
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• 2002

In the civil engineering and architecture fields, welding for large sectional members, such as I section steel and H section steel, are usually performed. a flash welding system, by which large I section steel or H section steel can be welded for a short time, was newly developed. In order to know the basic characteristics of welded joints, the specimens were cut out from flash welded joints, and tensile and fatigue experiments were carried out. The joint efficiency of welded joints by flash welding is 100% for the specimens with reinforcements and 93% for without reinforcements. The fatigue strength of welded joints with reinforcement was about 50% of that of the base metal. Removing the reinforcement generated by flash welding, fatigue strength of flash welded joints became 75% of that of the base metal. In case of flash welded joints with reinforcements, after a couple of fatigue cracks had propagated, ductile fracture occurred at the toe. In flash welded joints without reinforcements, fracture occurred at the bond or at HAZ (Heat Affected Zone). In case of fracture at the bond, fracture was brittle, and in case at HAZ, fracture was ductile.

• ALGAE
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• 제20권2호
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• pp.77-90
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• 2005

Eight species of Sargassum subgenus Bactrophycus section Teretia were collected from the coasts of Korea: S. confusum C. Agardh, S. pallidum (Turner) C. Agardh, S. muticum (Yendo) Fensholt, S. thunbergii (Mertens ex Roth) Kuntze, S. fulvellum (Turner) C. Agardh, S. hemiphyllum (Turner) C. Agardh, S. nipponicum Yendo, and S. miyabei Yendo. These species were investigated on morphological variations and geographical distribution in Korea. The valuable taxonomic characters between similar species of this section were discussed with special reference to thickness of leaves, types of holdfasts, shape of leaves and vesicle, and length of rhizoids.

• 한국안전학회지
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• 제28권5호
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• pp.21-26
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• 2013

Delamination of cover concrete due to re-bar corrosion is a critical damage reducing structural safety of reinforced concrete structures. Therefore, it should be detected and evaluated to provide appropriate maintenance to recover structural integrity. Impact-echo method, which utilizes thickness vibration characteristics of delaminated concrete section, is effective for detection and evaluation of small areal size delamination. However, it may not be applicable for large areal size delamination in which flexural vibration modes are dominated. In this study, applicability of vibration mode shapes of delaminated concrete section is investigated for visualization of delamination region in concrete structures. Numerical and experimental modal tests are performed to estimate mode shapes of delaminated concrete section and linear absolute summation technique is proposed for effective visualization of delamination region based on estimated mode shapes.

• Steel and Composite Structures
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• 제28권4호
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• pp.403-414
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• 2018

In this paper, the lateral-torsional buckling of axially-transversally functionally graded tapered beam is investigated. The structure cross-section is assumed to be symmetric I-section, and it is continuously laterally supported by torsional springs through the length. In addition, the height of cross-section varies linearly throughout the length of structure. The proposed formulation is obtained for the case that the elastic and shear modulus change as a power function along the beam length and section height. This structure carries two concentrated moments at the ends. In this study, the lateral displacement and twisting angle relation of the beam are defined by sinusoidal series. After establishing the eigenvalue equation of unknown constants, the beam critical bending moment is found. To validate the accuracy and correctness of results, several numerical examples are solved.

• Journal of Korean Dental Science
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• 제6권2호
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• pp.50-57
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• 2013

Purpose: Autogenous tooth bone graft is proven to be efficient. We evaluated the bone healing effect and clinical capabilities of autogenous tooth bone materials as a scaffold when growth factor is used together with this material. Materials and Methods: Subjects were those who needed implant placement and bone graft because of missing tooth or alveolar bone defect and who kept their autogenous tooth or needed extraction of other tooth. Group I included autogenous tooth bone graft with growth factor, whereas Group II had only autogenous tooth bone graft. We investigated the bone healing state through computed tomography taken just before surgery and 3 to 4 months after surgery to evaluate the effectiveness of bone graft. Group I had 9 patients, whereas Group II had 5 patients. We compared the pre- and post-operative increase of the Hounsfield unit and bone height by analyzing the computed tomography images. Result: Sinus bone grafts numbered 8 cases, and vertical ridge augmentation was performed together with 3 cases of these. Vertical ridge augmentation was performed in 2 cases, and horizontal ridge augmentation in 1 case alone. Socket graft was done in 3 cases. The post-operative mean value of the Hounsfield unit was 960 in Group I and 836.7 in Group II, but the increase was almost similar, i.e., 636.9 in Group I and 634.7 in Group II on the average. Increase of bone height was 7.6 mm in Group I and 11.1 mm in Group II on the average. This difference was attributable to the fact that most of the cases were sinus bone graft in Group II. Conclusion: In this study, we suggest the possibility of autogenous tooth bone graft materials as a scaffold besides their bone healing ability.

• 대한기계학회논문집B
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• 제23권11호
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• pp.1390-1398
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• 1999

A numerical analysis for ROT sparger of PWR(Pressurized Water Reactor) is carried out. Computation is performed to investigate the flow characteristics as the change of design factor. As the result of this study, RDT sparger's flow resistance coefficient is K=3.53 at the present design condition if engineering mar&in is considered with 20%, and flow ratio into branch pipe is $Q_s/Q_i=0.41$. Velocity distribution at exit is not uniform because of separation in branch pipe. In the change of inlet flow rate and section area ratio of branch pipe for main pipe, flow resistance coefficient is increased as $Q_s/Q_i$ decreasing, but in the change of branch angle and outlet nozzle diameter of main pipe, flow resistance coefficient is decreased as $Q_s/Q_i$ decreasing. As the change rate of $Q_s/Q_i$ is the larger, the change rate of flow resistance coefficient is the larger. The change rate of pressure loss is the largest change as section area ratio changing. The optimal design condition of sparger is estimated as the outlet nozzle diameter ratio of main pipe is $D_s/D_i=0.333$, the section area ratio is $A_s/A_i=0.2$ and the branch angle is ${\alpha}=55^{\circ}$.

• 한국산학기술학회논문지
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• 제8권6호
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• pp.1537-1542
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• 2007

본 논문에서는 기존 I형강 매입형 강합성 바닥판을 기본으로 새로운 형식의 초간편 강합성 바닥판 거더패널을 제시하여 가설중 거동에 대해 연구하였다. 범용해석프로그램인 ABAQUS를 사용하여 바닥판을 구성하는 인자에 대하여 영향을 평가하였다. 하부강판과 I형강의 용접량 변화, 1형강의 복부에 유공 유무, 유공의 위치변화에 대해 평가하였다. 또한 모델링의 합리적 검증을 위해 수계산, Shell요소, Solid요소 모델을 사용하여 비교하였다. 그 결과 하부강판과 I형강의 용접량 변화시 전체용접에 비해 부분용접시 지간 중앙부 단면에서 최대 휨 인장응력이 증가함을 확인할 수 있었다. 또한 유공이 있는 경우 유공이 없는 경우보다 처짐량이 약간 증가함을 확인할 수 있었다.