• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.199-200
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• 2012

Test method and requirements of fixed water-based fire-fighting systems for Ro-Ro spaces and special category spaces were introduced for research engineer's reference.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.946-952
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• 2013

Large scale fire tests were conducted to develop water mist nozzles as a component of fixed water- based fire fighting systems for Ro-Ro spaces and special category spaces. Fire scenarios for this system consist of two cases which are for cargo fire in a simulated truck and for passenger vehicle fire, and each case has 3 different tests according to the position between fixed water mist nozzles and fire source. Every experiment proceeded for 30 minutes and acceptance criteria were based on gas temperature, fuel package's damage and ignition of targets. This study primarily dealt with the experimental results of cargo fire and focused on fire suppression capability in accordance with discharge pressure, flow rate and flow characteristics like swirl and penetration of the developed water mist nozzles. It appeared that low pressure water mist nozzles with about 40 L/min were able to control fire occurred in Ro-Ro spaces.

• Communications of the Korean Mathematical Society
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• v.32 no.3
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• pp.567-578
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• 2017

Many scholars studied the boundedness of $Ces{\grave{a}}ro$ operators between $Q_K$ spaces and Bloch spaces of holomorphic functions in the unit disc in the complex plane, however, they did not describe the compactness. Let 0 < ${\alpha}$ < $+{\infty}$, K(r) be right continuous nondecreasing functions on (0, $+{\infty}$) and satisfy $${\displaystyle\smashmargin{2}{\int\nolimits_0}^{\frac{1}{e}}}K({\log}{\frac{1}{r}})rdr<+{\infty}$$. Suppose g is a holomorphic function in the unit disk. In this paper, some sufficient and necessary conditions for the extended $Ces{\grave{a}}ro$ operators $T_g$ between ${\alpha}$-Bloch spaces and $Q_K$ spaces in the unit disc to be bounded and compact are obtained.

• Communications of the Korean Mathematical Society
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• v.24 no.1
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• pp.57-66
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• 2009

In this paper, we characterize the boundedness and compactness of the extended $Ces{\grave{a}}ro$ operators from general function spaces F(p, q, s) to Bloch-type spaces ${\mathcal{B}}_{\mu}$ where $\mu$ is normal function on [0,1).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.738-741
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• 2003

In general, the essential requirement for cruisers or car ferries is the reduction in noise to ensure high quality and comfort. Recently, the Ro-Ro Passengers Ferry (ROPAX) was built in Hyundai Heavy Industries. In order to minimize the noise levels, careful attention have to De paid by the special committee of experts from the initial design stage to the sea trial. Proper countermeasures, considering the characteristics of sources and receiver spaces, were applied from the noise prediction and various experiment results. Finally, this ship was successfully delivered with excellent noise properties. This paper describes the procedure of noise analysis, the countermeasures of noise control, and the measurement results of the sea trial. Onboard noise analysis had been carried out by statistical energy analysis program and outdoor noise prediction program based on ISO9614. The prediction results are in good agreements with the measurement results. The technology to minimize the noise levels for cruisers or car ferries has been established throughout the construction of this ship.

• The Mathematical Education
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• v.23 no.2
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• pp.55-59
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• 1985

In this paper we obtain several results on the existence of common fixed points, of commuting mappings on PM-spaces and give an application. Our results generalize a multitude of fixed point theorems in PM-spaces.

• Bulletin of the Korean Mathematical Society
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• v.54 no.2
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• pp.705-714
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• 2017

Let $A^2_{{\alpha},{\beta}}(\mathbb{B}_n)$ denote the space of holomorphic functions that are $L^2$ with respect to a weight of form ${\omega}_{{\alpha},{\beta}}(z)=(1-{\mid}z{\mid}^{\alpha}e^{-{\frac{\beta}{1-{\mid}z{\mid}}}}$, where ${\alpha}{\in}\mathbb{R}$ and ${\beta}$ > 0 on the unit ball $\mathbb{B}_n$. We obtain some results for the boundedness and compactness of $Ces{\grave{a}}ro$ operator on $A^2_{{\alpha},{\beta}(\mathbb{B}_n)$.

• Journal of Ocean Engineering and Technology
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• v.33 no.2
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• pp.196-202
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• 2019

In this study, the excessive noise and vibration phenomena of a high-speed Ro/Ro passenger ship were analyzed, and a countermeasure was taken based on them. This ship was granted a comfort class notation by the classification society, which was COMFORT-VIBRATION-II and COMFORT-NOISE-CREW-II. However, unfortunately, excessive noise and vibration in the aft part of the ship were delivered from the twin shaft propellers, and therefore the Class Requirement was not satisfied before delivery. In order to obtain the class notation, all of the concerned parties came to an agreement to reduce the noise and vibration level during operation after delivery because a seasonal ferry service was already scheduled and the cabin was fully booked. The root cause of the massive amount of noise and vibration was mainly the propeller-induced excitation pulse and beating that occurred from the mismatch of the rotating speeds of the two shaft lines. A 1st order vibrating force and beating phenomena existed in the propeller. Thus, a reduction of the excitation force, elimination of the beating phenomena, and decrease of the noise level at the aft area cabins and public spaces were required. In addition, structural reinforcements were conducted using pillars and additional girders at the aft part of the decks.

• Bulletin of the Korean Mathematical Society
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• v.35 no.2
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• pp.311-317
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• 1998

For Hilbert spaces H, K, a compact operator T: H $\rightarrow$ K, and column, row, operator Hilbert spaces $H_c,\;K_c,\;H_r,\;K_r,\;H_o, K_o$,we show that ${\parallel}T_{co}{\parallel}_{cb}={\parallel}T_{ro}{\parallel}_{cb}={\parallel}T_{oc}{\parallel}_{cb}={\parallel}T_{or}{\parallel}_{cb}={\parallel}T{\parallel}_4$.

• Journal of the Korean Society of Industry Convergence
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• v.9 no.1
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• pp.29-35
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• 2006

The population of Daegu, the third biggest city in Korea, is two point six million. Daegu is known as a basin or a city where it is not only too hot in summer but also too cold in winter. Recently with redevelopment apartment house boom, a 40-story or more apartment complexes are under construction near Shin-cheon and Dondaegu-ro, the south-north axis of Daegu. It is necessary to raise several points about blocking a road of the wind by high-rise apartment buildings and apartment complexes. As a kind of the green policy, Daegu enlarge the distance between apartment building by reconstructing low-rise apartment into high-rise and impose a duty of a green space on the ground by making a parking zone into an underground. Through this process, apartment complexes changed from a '一'shape to a '口'shape. It increases heat island phenomenon of a city by blocking a road of the wind that comes from Shin-cheon and Dondaegu-ro. To circulate the polluted air of Daegu basin, we need local wind. There are four effective measures. 1) Throw three greens into one in the center of the road at the north side in the same way of the south side of Dongdaegu-ro, 2) reflect the information of roads of the wind including heights, spaces and directions of buildings, 3) steer clear of a high-rise buildings and development apartment house constructions, and 4)select a city for benchmarking to be the environmental capital.