• 한국항공우주학회지
• /
• 제33권7호
• /
• pp.59-69
• /
• 2005

본 논문에서는 위상평활화코드 기법에 기반한 실시간 동적 차분위성항법의 효율적인 구현을 위하여 위치영역 Hatch 필터를 새로이 제안하고 그 성능을 분석하였다. 제안된 위치영역 Hatch 필터는 기존의 거리영역 Hatch를 새로운 각도에서 해석하고 이를 연장하여 유도되었다. 시뮬레이션을 통하여 Hatch 이득이 Kalman 형 이득보다 더 효율적이며 또한 위성의 출몰이 빈번한 환경에서는 위치영역 Hatch 필터가 거리영역 Hatch 필터보다 유리함을 보였다.

• 한국기계연구소 소보
• /
• 통권14호
• /
• pp.157-168
• /
• 1985

In cargo vessels, hatch covers are used to prevent sea water from penetrating into the cargo hold and to keep the vessels buoyant. And also they can be used as cargo loading devices as in container ships. In this paper, hatch covers are classified according to their operation method and their characteristics are briefly demonstrated. Systematic description on the scantling of the hatch cover panel and how to determine the capacity of the hydraulic power system fir folding hatch cover panels are also presented. The hydraulic power system is selected from the result of dynamic analysis of the movements of the hatch cover panels when stored on the upper deck. The hatch coaming height is determined as shortly as the hydraulic cylinders can be installed. This study deals with the hatch cover system of the medium sized multi-purpose cargo vessel, but the results of this study can be applied to large-sized cargo vessels with a slight change of the input data in the calculations. Further research on the high pressure pump, hydraulic cleating system and hydraulic piping will realize domestic production of the whole hatch cover system which have been supplied from foreign makers until now

• 한국항공우주학회지
• /
• 제34권2호
• /
• pp.48-55
• /
• 2006

본 논문에서는 실시간 동적 차분 위성항법과 관련하여 근래에 제안된 위치영역 Hatch 필터의 오차 특성을 해석하였다. 위치영역 Hatch 필터에 의하여 생성되는 잉여값 순열 (residual sequence)이 고장검출에 유용한 백색잡음 (white noise) 특성을 가짐을 보였으며, 위치영역 Hatch 필터는 기존에 알려진 위치영역 Kalman 형 필터에 비하여 전 상태 추정치 (a priori state estimate) 의 정확도 면에서 오히려 더 우수함을 해석적으로 보였다. 이와 같은 특성에 의하면 차분 위성항법의 다양한 응용분야에서 위치영역 Hatch 필터가 고장검출 및 정밀측위에 효율적으로 사용될 수 있음을 알 수 있다.

• 대한기계학회논문집A
• /
• 제38권1호
• /
• pp.89-99
• /
• 2014

본 논문에서는 유도탄 해치시스템의 스플라인 백래시에 의한 토크 외란에 대하여 실험을 통한 분석을 다룬다. 유도탄 해치시스템은 무거운 해치를 수직으로 상승시키기 위하여 스플라인과 기어열을 사용하고 있다. 해치의 회전축에 적용된 스플라인은 일반적으로 큰 동력전달을 위한 자동차의 구동 부품으로 사용된다. 스플라인은 각도 백래시를 갖고 있으며, 저크를 발생시킨다. 또한 해치 스플라인의 백래시는 해치의 흔들림 발생에 영향을 준다. 스플라인 백래시와 해치의 흔들림은 해치 회전각 및 해치의가속도를 측정함으로써 실험적으로 분석된다. 해치의 흔들림은 짧은 시간동안 육안으로 관찰되며, 회전각의 변화 및 해치 가속도에 의해 측정된다. 해치의 각 변화에 대한 변동형태 및 지속시간은 토크와 유사하며, 백래시에 의한 해치의 흔들림은 토크 외란을 발생시킴을 보여준다.

• 한국가금학회지
• /
• 제22권1호
• /
• pp.1-6
• /
• 1995

A total of 514 birds were used to investigate the influence of body weight and shank length at hatch on the body weights at various ages in growing pheasant. Statistical model included the terms of hatch and sex as fixed effects and the two covariates of body weight and shank length at hatch. In this model, the effects of hatch and sex on the body weights at the age of 4, 8, 12, 16 and 20 wk, and the average daily gains from hatch to 8 wk and from 8 to 16 wk of age were highly significant(P<0.01). All the regression coefficients of body weights and average daily gains on the body weight at hatch were also significant(P<0.01). Their estimates were 3.05.7.21. 13.89, 15.18 and 15.33 for the body weights at 4. 8, 12, 16 and 20 wk of age ; 0.111 and 0.142 for the average daily gains from hatch to 8 wk, and from 8 to 16 wk of age, respectively. On the shank length, only the regression coefficients of the body weights at 4 and 8 wk of age and the average daily gains from hatch to 8 wk of age were significant(P<0.01). Results of this study suggest that body weight at hatch do significantly affect the body weights in the growing periods up to' the 20 wk of age, but the shank length at hatch influences the body weights only at early age.1)

• Asian-Australasian Journal of Animal Sciences
• /
• 제23권4호
• /
• pp.515-520
• /
• 2010

The response of broiler chicks to intubation of nutrients (starch, casein, soybean oil or their combinations) into the crop immediately after hatch was evaluated for performance, intestinal development, meat yield and immune competence up to 35 d of age. A control group with no access to feed and two test groups fed either inert material (sawdust) or starter diet for the initial 24 h after hatch were compared with nutrient intubated groups (n = 7). A total of 300 broiler chicks were equally distributed to 10 dietary groups with 6 replicates of 5 chicks each. After 24 h of hatch, all groups were fed ad libitum the starter (0-21 d) and finisher diets (22-35 d). Results indicated that post-hatch intubation of starch into the crop significantly (p${\leq}$0.05) improved body weight (at 14 and 35 d of age), readyto-cook meat yields, weights of breast muscle and small intestine segments, cell-mediated immune response, ND titers and weight of bursa compared to chicks starved or fed sawdust during the initial 24 h after hatch. However, chicks with access to feed immediately after hatch or intubation of starch, soybean oil, starch+casein, starch+soybean oil or starch+casein+soybean oil exhibited similar positive effects. Intubation of casein either alone or in combination with soybean oil was superior to the starved or sawdust fed groups, but inferior to other groups for all the parameters studied. It was concluded from the study that intubation of starch individually or in combination with casein and/or soybean oil effectively circumvented the negative effects of post-hatch starvation for 24 h. Among the nutrients intubated, carbohydrate (starch) was better utilized by the chicks than protein (casein) or fat during the initial post-hatch period.

• 제어로봇시스템학회논문지
• /
• 제19권12호
• /
• pp.1111-1118
• /
• 2013

In this paper, the disturbance applied to launcher hatch by ship motions is introduced to identify the vertical ship motion disturbance. Basically, ship motions are comprised of 6 degrees of freedom: roll, pitch, yaw, heave, surge and sway. In the case of the shipboard launcher hatch the coupled pitch, heave and roll are significant motions to be transformed to a vertical direction motion. The maximum acceleration values are obtained from the vertical motion model and the ship motion data in accordance with ship type and hatch location on the ship. We verify that the maximum pitch motion mainly influences the launcher hatch and also present the quantity of the maximum load disturbance by the ship's motion acceleration.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제7권2호
• /
• pp.270-287
• /
• 2015

According to the increase of the operating cost and material cost of a ship due to the change of international oil price, a demand for the lightening of the ship weight is being made from various parties such as shipping companies, ship owners, and shipyards. To satisfy such demand, many studies for a light ship are being made. As one of them, an optimal design method of an existing hull structure, that is, a method for lightening the ship weight based on the optimization technique was proposed in this study. For this, we selected a hatch cover of a bulk carrier as an optimization target and formulated an optimization problem in order to determine optimal principal dimensions of the hatch cover for lightening the bulk carrier. Some dimensions representing the shape of the hatch cover were selected as design variables and some design considerations related to the maximum stress, maximum deflection, and geometry of the hatch cover were selected as constraints. In addition, the minimization of the weight of the hatch cover was selected as an objective function. To solve this optimization problem, we developed an optimization program based on the Sequential Quadratic Programming (SQP) using C++ programming language. To evaluate the applicability of the developed program, it was applied to a problem for finding optimal principal dimensions of the hatch cover of a deadweight 180,000 ton bulk carrier. The result shows that the developed program can decrease the hatch cover's weight by about 8.5%. Thus, this study will be able to contribute to make energy saving and environment-friendly ship in shipyard.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제32권2호
• /
• pp.154-161
• /
• 2010

Many edentulous posterior maxilla are found to be compromised by alveolar resorption and increased pneumatization of the sinus. One of the surgical procedures to overcome this anatomical limitation is sinus floor elevation with bone graft, which is reported as more appropriate and more successful procedure. Commonly, if the residual bone height is over 5mm, sinus floor elevation is operated through transcrestal approach using osteotome technique. But, it is possible for patients to feel discomfort during operation and dizziness after operation while malleting, sinus floor elevation, using osteotome technique. Some instruments and methods has been used to overcome these problems and use more easily. The aim of this study is to compare between the surgical procedure of sinus floor elevation using Hatch reamer technique and that of sinus floor elevation using osteotome technique. From 2004 Feb to 2007 Oct, we investigate patients (osteotome group: 72, Hatch reamer group: 70) who were given implant surgery with sinus floor elevation (osteotome group: 92, Hatch reamer group: 98). We analysed gender, age, residual bone height, amount of sinus floor elevation, used graft material, total success rate, failure rate by residual bone height and implant type and discomfort during operation, etc. The results obtained were as follows. 1. In the amount of sinus elevation was osteotome group was $3.85{\pm}1.02\;mm$ and Hatch reamer group was $3.93{\pm}1.38\;mm$. There was no statistically significant difference between the two groups (P > 0.05). 2. At the total success rate, osteotome group was 92.4% and Hatch reamer group was 94.9%. There was no statistically significant difference between the two groups (P > 0.05). 3. On the discomfort during the operation by using numerical rating scale, osteotome group was $2.87{\pm}0.83$ and Hatch reamer group was $1.12{\pm}0.64$. There was statistically significant difference between the two groups (P < 0.05). The Hatch reamer group clinical results was similar to osteotome group and we thought that Hatch reamer technique can overcome the faults of osteotome technique.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
• /
• pp.177-178
• /
• 2006

Post panamax급 container vessel에 hatch cover용 bearing pad type을 flexible pad로 확대 적용하여 경쟁력 확보