• Ocean and Polar Research
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• v.28 no.3
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• pp.237-243
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• 2006

The ages of sandfish, Arctoscopus japoninis sampled from the eastern sea of Korea, were determined by the transverse section method of otoliths. Ages were assigned to every individual according to the number of opaque zones, and then fitted to the von Bertalanffy growth equation. Estimated equations were $L_t=25.90(1-e^{-0.2976(t+0.4447)})$ for females and $L_t=21.38(1-e^{-0.2917(t+1.2087)})$ for males, where t is age (year) and $L_t$, is body length (mm) at age t. These two equations were significantly different and the body length of females calculated from the equation was larger than that of males except at 1 year old.

• ETRI Journal
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• v.44 no.4
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• pp.543-559
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• 2022

To determine a suitable waveform for Internet of Things (IoT) transmission over low-Earth orbit (LEO) satellites, this paper reports the results of a performance comparison between chirp spread spectrum (CSS)-based LoRa and direct sequence spread spectrum (DSSS)-based Ingenu. The performance of both waveforms was measured in terms of the packet error rate, throughput, and packet loss rate, considering the Doppler effect caused by the high speed of LEO satellites and the interference among multiple terminals. Simulation results indicate that the DSSS scheme is more suitable than the CSS scheme for high-traffic IoT services because of its robustness against interference among multiple terminals. However, the CSS scheme is more suitable than the DSSS scheme for high-mobility IoT services because of its robustness against the Doppler effect. We discuss various solutions, such as the preprocessing of Doppler effect and avoidance of packet collision, to enhance the performance of the DSSS and CSS schemes. The simulation results of the proposed solution show that the enhanced DSSS scheme can be a proper waveform in IoT transmission over LEO satellites for both the high-traffic and high-mobility services.

• International Journal of Aeronautical and Space Sciences
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• v.8 no.1
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• pp.32-45
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• 2007

The T-50 advanced supersonic jet trainer employs the Relaxed Static Stability (RSS) concept to improve the aerodynamic performance while the flight control system stabilizes the unstable aircraft and provides adequate handling qualities. The T-50 flight control laws employ a proportional-plus-integral type controller based on a dynamic inversion method in longitudinal axis and a proportional type controller based on a blended roll system with simple roll rate feedback and beta-betadot feedback system. These control laws are verified by flight tests with various maneuver set flight envelopes and the control laws are updated to resolve flight test issues. This paper describes several concepts of flight control laws used in T-50 to resolve those flight test issues. Control laws for solving the roll-off problem during pitch maneuver in asymmetric loading configurations, improving the departure resistance in negative angle of attack conditions and enhancing the fine tracking performance in air-to-air tracking maneuvers are described with flight test data.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.302-307
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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 during up-end milling of Inconel 718 using measured cutting forces. The specific cutting resistance, K. and $K_t$ are defined as the radial and tangential cutting forces divided by the modified chip section area. Both of $K_r$, and $K_t$ values become smaller as the helix angle increases from $30^\circ$ to $40^\circ$ Whereas they become larder as the helix angle increases from $40^\circ$ to $50^\circ$. On the other hand, the $K_r$, and $K_t$ values show a tendency to decrease with increase of the modified chip section area and this tendency becomes distinct with smaller helix angle.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.5
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• pp.45-52
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• 2002

In an end milling process, the undeformed chip section area and cutting forces vary periodically with the phase change of the tool. However, the real undeformed chip section area deviates from the geometrically ideal one owing to the cutter runout and tool shape error. In the current study, a method of estimating the real undeformed chip section area which reflects the cutter runout and tool shape error is presented during up-end milling processes of Inconel 718. The specific cutting forces, $K_r$ and $K_t$ are defined as the radial and tangential cutting forces divided by the modified chip section area, respectively. Both of the $K_{r}$ and $K_t$ values become smaller as the helix angle increases from $30^{\circ}$ to $40^{\circ}$. Whereas they become larger as the helix angle increases from $40^{\circ}$ to $50^{\circ}$. The $K_r$ and $K_t$ values show a tendency to decrease with increase of the modified chip section area.a.

• Annual Conference on Human and Language Technology
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• 2023.10a
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• pp.707-710
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• 2023

관계추출은 문장 내 두 개체 간의 의미적 관계를 추론하는 자연어분석 태스크이다. 딥러닝의 발전과 더불어 관계추출은 BERT 계열의 이해형 언어모델을 이용하였다. 그러나, ChatGPT의 혁신적인 등장과 함께, GPT계열의 생성형 언어모델에 대한 연구가 활발해졌다. 본 논문에서는 소규모의 생성형 언어모델(Kebyt5)을 이용하여 관계추출 성능개선을 위한 프롬프트 구성 및 생각의 사슬(CoT) 학습 방법을 제안한다. 실험결과 Kebyt5-large 모델에서 CoT 학습을 수행하였을 경우, Klue-RoBERTa-base 모델보다 3.05%의 성능개선이 있었다.

• Women's Health Nursing
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• v.5 no.1
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• pp.5-20
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• 1999

This study was conducted to examine primiparas' perception of delivery experience and identity as the mother("Myself as the Mother" and "My Baby") according to delivery methods such as normal delivery and cesarean section. The result of this study summarized as follows. 1. The primiparas' perception of delivery experience according to delivery methods showed that the primipars who had normally delivered perceives the delivery experience more positively than those by cesarean section(t=4.88, p=0.000). This fact supported hypothesis 1 that "the primiparas group by normal delivery should perceive the delivery experience more positively that by cesarean section." 2. The primiparas who had delivered by cesarean section were more positive in the SD-Self score than those who had normally delivered at the time when four weeks passed after delivered, and there was a significant difference(t=-4.21, p\0.000). Therefore, hypothesis 2-1 that "the primiparas group who had normally delivered should be more positive in the SD-Self 1-2 days and 4 weeks after delivery than one who delivered by cesarean section" was rejected. 3. It was shown that the primiparas who had delivered normally were more positive in the SD-Baby 1-2 days 4 weeks after delivery than those who delivered by cesarean section(after-delivery 1-2 days : t=3.10, p=0.002 and after-delivery 4 weeks : t=2.15, p=0.034). Based on this fact, hypothesis 2-2 that "the primiparas group who had delivered normally should be more positive in the SD-Baby 1-2days and 4 weeks after delivery than those who had delivered by cesarean section"was supported. 4. Primiparas who had delivered by cesarean section appeared to have a positive identity as the mother by showing a more significant difference (t=7.96, p=0.000) 4 weeks after delivery than 1-2 days after delivery. In conclusion, we see that primiparas' perception of delivery experience and identity as the mother were different according to delivery methods. Thus, it is required to devise a nursing in tervention strategy to expand support from the health care system and opportunities to provide pre. post-delivery programs so that primiparas can have a positive perception of delivery experience and a positive identity as the mother. Based on conclusion stated above, the following suggestions are made. 1. As this study compared the perception of delivery experience and identity as the mother between prmiparas who had delivered normally and ones who had delivered by cesarean section, the further study on comparison between multiparas who had delivered normally and ones who had delivered by cesarean section is needed. 2. According to the results of this study, longitudinal study is needed to examine the difference and change in the formation of maternal identity. 3. According to the result of this study, a study is also needed to determine interaction between time for maternal identity and delivery methods.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.139-142
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• 2003

Traditionally, the thickness of fire protection materials of structural elements such as beam and column have been decided by fire test using the predominant steel section of $H-300{\times}300{\times}10{\times}15$ for column and $H-400{\times}200{\times}8{\times}13$ for beam in Korea. But this way of determination of fire protection thickness yields very unduly results. Because the temperature-increment rate of structural steel elements depends mainly on magnitude of their cross-areas. In general, the thicker size of cross-areas for structural elements, the lower temperature shows up. It had already proved that the fire protection thickness only depends on the size of cross-areas and the fire protection method for three-fide or four-side exposed conditions in European countries, the United State of America and so on. To demonstrate there would be differences among various cross-areas for structural elements, we conducted several fire tests with full-scale specimens of beams and columns. For the determination of critical temperature for steel section when the fire resistant performance is needed to be decided, we conducted with a loaded fire test for beam and column, respectively. The small column in 1.0 meter length and beam in 1.5 meter length were used in order to deprive the rational fire protection thickness of structural elements such as beam and column, respectively. After test, we could obtain there were significant temperature lass between higher cross-areas and lower cross-areas. The critical temperature of steel as a criterion is used 538$^{\circ}C$ for column and 593$^{\circ}C$ for beam which is from ASTM E 119 because we don't make provisions as critical temperature by elements. We could consider that the best way of determination of fire protection thickness is using the following multi-regression equation which was deprived from several fire tests using the concept of section factor, FR(column) = 0.17 +5191.49t A/Hp + 40.77t, FR(beam) = 0.25 +6899.31t A/Hp + 32.60t(where, FR means fire resistant time, t means thickness, A means cross-area and Hp means heated parameter).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.2
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• pp.91-98
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• 2021

Objectives: Hyaluronoglucosaminidase (hyaluronidase) increases the local intercellular permeability of the peripheral lymphatic channel and capillaries, which may help reduce edema. In the present study, the effects of hyaluronidase on postoperative edema and pain reduction were evaluated. Materials and Methods: The study included 38 patients who underwent guided bone regeneration (GBR) surgery before implantation. Patients were randomly assigned to either the control group (n=20) or the test group (n=18). Hyaluronidase was injected into the GBR site of subjects in the test group. Postoperative edema was evaluated by measuring the distance between specific facial landmarks immediately after surgery (T1) and 2-4 days after surgery (T2). The degree of pain at T2 and at 10-14 days after surgery (T3) was assessed. Results: In the test group, the degree of swelling was lower than in the control group, however, only two measurements, from the tragus to the mouth corner and from the outer canthus to the mouth corner, showed statistically significant differences (P=0.012 and P=0.001, respectively). The anti-edema effect of hyaluronidase was more effective in the maxilla than in the mandible. In the maxilla, the percentage of facial swelling was significant for three measurements. However, in the mandible, the percentage of facial swelling was significant for only one measurement. Low levels of pain that were similar at T2 and T3 were reported in both groups. Conclusion: The results indicate the degree of swelling was lower in the test group and hyaluronidase appeared to be more effective in the maxilla. The degree of pain reduction was similar between groups. Further in vivo and randomized controlled trials with larger sample sizes are warranted.

• Journal of Korean Association for Spatial Structures
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• v.18 no.1
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• pp.127-134
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• 2018

This study suggests the tangent modulus $E_t$ associated with partially yielded section of steel member under axially compressed. The provisions for column strength does not provide a information about failure mode of structural system. So, designers can not evaluate that a failure comes from member buckling or material yielding. The material of the axially compressed column under inelastic behavior reaches yielding point before the axial force renders the column bent. If axial members yields not by buckling effect but gradually yielding effect of material, the design code should accept related tangent modulus Et which is based on gradual yielding effect of material. This study provides the new effective tangent modulus $E_t$ derived in the case that residual stress is 30 percent and 50 percent of yielding stress respectively. The study considers idealized I section of steel which ignores web and general I section of steel with web respectively and makes conclude that tangent modulus $E_t$ with idealized I section of steel is rational.