• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.8-8
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• 1987

This paper describes on the distribution of the vibration and the noise produced on a skipjack pole and line training ship M/S Pusan 403 (243GT, 1,000ps) under the cruising or drifting condition. The vibration and the noise level were measured by use of protable vibration analyzer (B and K 3513) and sound level meter (B and K 2205), and so the vibration level was converted into dB unit. The check points were set through every decks and around important places of the ship. The results obtained can be summarized as follows: 1. The vibration and the noise level 1) On the main deck, both the vibration and the noise level were highest at the vertically above the main engine, whereas the vibration level was the lowest in the bow store and the noise level beneath the bridge. 2) Under cruising condition, the vibration level around the cylinder head of main engine, port side of the engine room, on the shaft tunnel was 80, 67, 65 dB and the noise level 104, 87, 86 dB, respectively. 3) The vibration level on the vertical line passing through the bridge was the highest at the orlop deck with 60 dB and the lowest on the bridge deck with 55 dB, whereas the noise level the highest at the compass deck with 75 dB and the lowest at the orlop deck with 53 dB. 4) The vibration and the noise level on the open decks were the highest with 65 dB and 84 dB on the boat deck, whereas the vibration level was the lowest at the lecture room with 51 dB and the noise level the lowest at the fore castle deck with 57 dB. 5) On the orlop decks, both the vibration and the noise level were the highest at the engine room with 65 dB and 85 dB, and the lowest at bow store with 54 dB and 52 dB, respectively. Comparing with the vibration level and the noise level, the vibration level was higher than the noise level in the bow part and it was contrary in the stern part of the ship. 2. Vibration analysis 1) The vibration displacement and the vibration velocity were the greatest at the cylinder head of main engine with 100μm and 11mm/sec, and were the smallest at the compass deck with 3μm and 0.07mm/sec. They were also attenuated rapidly around the frequency of 100Hz and over. 2) The vibration acceleration was the greatest at the cylinder head with the main frequency of 1KHz and the acceleration of 1.1mm/sec super(2), and the smallest at the compass deck with 30KHz and 0.05mm/sec super(2).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.54-60
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• 1987

This paper describes on the distribution of the vibration and the noise produced on a skipjack pole and line training ship M/S Pusan 403 (243GT, 1,000ps) under the cruising or drifting condition. The vibration and the noise level were measured by use of protable vibration analyzer (B and K 3513) and sound level meter (B and K 2205), and so the vibration level was converted into dB unit. The check points were set through every decks and around important places of the ship. The results obtained can be summarized as follows: 1. The vibration and the noise level 1) On the main deck, both the vibration and the noise level were highest at the vertically above the main engine, whereas the vibration level was the lowest in the bow store and the noise level beneath the bridge. 2) Under cruising condition, the vibration level around the cylinder head of main engine, port side of the engine room, on the shaft tunnel was 80, 67, 65 dB and the noise level 104, 87, 86 dB, respectively. 3) The vibration level on the vertical line passing through the bridge was the highest at the orlop deck with 60 dB and the lowest on the bridge deck with 55 dB, whereas the noise level the highest at the compass deck with 75 dB and the lowest at the orlop deck with 53 dB. 4) The vibration and the noise level on the open decks were the highest with 65 dB and 84 dB on the boat deck, whereas the vibration level was the lowest at the lecture room with 51 dB and the noise level the lowest at the fore castle deck with 57 dB. 5) On the orlop decks, both the vibration and the noise level were the highest at the engine room with 65 dB and 85 dB, and the lowest at bow store with 54 dB and 52 dB, respectively. Comparing with the vibration level and the noise level, the vibration level was higher than the noise level in the bow part and it was contrary in the stern part of the ship. 2. Vibration analysis 1) The vibration displacement and the vibration velocity were the greatest at the cylinder head of main engine with 100$\mu$m and 11mm/sec, and were the smallest at the compass deck with 3$\mu$m and 0.07mm/sec. They were also attenuated rapidly around the frequency of 100Hz and over. 2) The vibration acceleration was the greatest at the cylinder head with the main frequency of 1KHz and the acceleration of 1.1mm/sec super(2), and the smallest at the compass deck with 30KHz and 0.05mm/sec super(2).

• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.69-80
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• 1998

This research was designed to investigate how the exercise program affects paraplegic standing and walking employing functional electrical stimulation(FES). Emphasis was also given to fatigue of major lower extremity muscles induced by different types of electrical stimulation. We applied continuous and intermittent rectangular pulse trains to quadriceps of 10 normal subjects and 4 complete paraplegic patients. The frequencies were 20Hz and 80Hz, and the knee angle was fixed at 90$^{\circ}$and 150$^{\circ}$to investigate how muscle fatigue is related to muscle length. The knee extensor torque was measured and monitored. We have been training quadriceps and gastrocnemius of a male paraplegic patient by means of electrical stimulation for the past two year. FES standing was initiated when the knee extensors became strong enough to support the body weight, and then the patient started FES walking utilizing parallel bars and a walker. We used an 8-channel constant-voltage stimulator and surface electrodes. The experimental results indicated that paralyzed muscles fatigued rapidly around the optimal length contrary to normal muscles and confirmed that low frequency and intermittent stimulation delayed fatigue. Our exercise program increased muscle force by approximately 10 folds and decreased the fatigue index to half of the initial value. In addition, the exercise enabled the patient to voluntarily lift each leg up to 10cm, which was of great help to the swing phase of FES walking. Both muscle force and resistance to fatigue were significantly enhanced right after the exercise was applied every day instead of 6 days a week. Up to date, the patient can walk for more than two and half minutes at 10m/min while controlling the on/off time of the stimulator by pushing the toggle switch attached to the walker handle.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.766-775
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• 1997

Background : Primary malignant tumors of the trachea are extremely rare entities and account for a mere 0.1 per cent of all malignancies of the respiratory tract. Because of vague localizing signs, symptoms and a usually negative routine chest film, the patients with tracheal tumors are often treated for asthma or chronic obstructive pulmonary disease for considerable period of time before correct diagnosis. Method : We have made a review of the 17 cases of primary tracheal tumors in recent 15 years. We reviewed the clinical features including history of smoking and respiratory symptoms, the official readings of initial routine chest film, the cytologic examination of sputum, the time of delay in diagnosis, and the response according to the therapeutic modalities. Results : Eight out of 9 patients with squamous cell carcinoma(SCC) were above 50 years old, five out of 6 patients with adenoid cystic carcinoma(ACC) were below 50 years old. The most common location of primary tracheal tumors was the upper one-third of trachea in 8 cases(47%). The most frequent symptoms were dyspnea in 13/17 cases(76%) and then stridor or wheezing, cough. and sputum in order. The routine chest roentgenographic examinations were not helpful to diagnose tracheal carcinoma and the cytologic examinations of sputums were helpful to diagnose tracheal carcinoma in only one case with adenocarcinoma. The mean times of delay in diagnosis of patients with sec and ACC were 5 months and 24.9 months respectively. We had bronchial asthma in 8 cases(47%) and tracheal tumors in 4 cases(23%) as initial clinical impression. Conclusion : We would like to perform more comprehensive diagnostic tools(high KVP technique, the fibroptic bronchoscopic examination, chest CT scan etc.) in patients who had the suggestive points for the tracheal tumorse(1. unexplained hemoptysis or hoarsness, 2. inspiratory wheezing or stridor, 3. wax and waning of dyspnea according to changes of position, 4. progressive asthmatics unresponsive to antiasthmatic therapy) and radical resection of tumor or external radiation therapy with curative aim as possible.

• Tuberculosis and Respiratory Diseases
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• v.64 no.2
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• pp.125-132
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• 2008

Background: In chronic obstructive pulmonary disease (COPD) patients, the serum levels of C-reactive protein (CRP) are elevated and an increase of CRP is more exaggerated in the acute exacerbation form of COPD (AECOPD) than in stable COPD. Pulmonary arterial hypertension is a common complication of COPD. An increased level of CRP is known to be associated with the risk of systemic cardio-vascular disorders. However, few findings are available on the potential role of CRP in pulmonary arterial hypertension due to COPD. Methods: This study was performed prospectively and the study population was composed of 72 patients that were hospitalized due to AECOPD. After receiving acute management for AECOPD, serum CRP levels were evaluated, arterial oxygen pressure ($PaO_2$), was measured, and the existence of pulmonary arterial hypertension under room air inhalation was determined in the patients. Results: The number of patients with pulmonary arterial hypertension was 47 (65.3%)., There was an increased prevalence of pulmonary arterial hypertension and an increase of serum CRP levels in patients with the higher stages of COPD (e.g., patients with stage 3 and stage 4 disease; P<0.05). The mean serum CRP levels of patients with pulmonary arterial hypertension and without pulmonary arterial hypertension were $37.6{\pm}7.4mg/L$ and $19.9{\pm}6.6mg/L$, respectively (P<0.05). However, there was no significant difference of the mean values of $PaO_2$ between patients with pulmonary arterial hypertension and without pulmonary arterial hypertension statistically ($77.8{\pm}3.6mmHg$ versus $87.2{\pm}6.0mmHg). Conclusion: We conclude that higher serum levels of CRP can be a sign for pulmonary arterial hypertension in AECOPD patients.

• Journal of the Korean Electrochemical Society
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• v.8 no.4
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• pp.172-176
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• 2005

Recently, many researches on the high-voltage 5 V class cathode material have focused on $LiNi_{0.5}Mn_{1.5}O_4$, where $Mn^{3+}$ in the existing $LiMn_2O_4 (Li[Mn^{3+}][Mn^{4+}]O_4)$ is replaced by $Ni^{2+}(Li[Ni^{2+}]_{0.5}[Mn^{4+}]_{1.5}O_4)$ in order to utilize $Ni^{2+}/Ni^{4+}$ redox reaction in the 5V region. The partial substitution of Mn in $LiMn_2O_4$ for other transition metal element, $LiM_yMn_{1-y}O_4$(M=Cr, Al, Ni, Fe, Co, Cu, Ga etc) is known as a good solution to overcome the problems associated with $LiMn_2O_4$ like the gradual capacity fading. In this study, we synthesized $LiNi_{0.5}Mn_{1.5}O_4$ through a mechanochemical process and investigated its morphological, crystallographic and electrochemical characteristics. The results showed that 4 V peaks had been found in the cyclic volammograms of the synthesized powders due to the existence of $Mn^{3+}$ from the incomplete substitution of $Ni^{2+}$ for $Mn^{3+}$ implying that the mechanochemical activation alone was not good enough to synthesize an exact stoichiometric compound of $LiNi_{0.5}Mn_{1.5}O_4$. The synthetic condition of mechanochemical process, such as type of starting materials, ball-mill and calcination condition was optimized for the best electrochemical performance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.544-549
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• 2014

In this study, the permeation efficiency (PE) of sea tangle (Laminaria japonica) extract (STE) into egg using the temperature change method (TCM) and pressure was investigated. STE was prepared in a volume of water equal to 10 times the weight of the sea tangle at $100^{\circ}C$ over a 3 hr period. The PE of iodine as a representative component of the STE as well as the total polyphenol content at ambient pressure were determined as follows: 1) after soaking in the STE at 30, 40, and $50^{\circ}C$ for 3 hr, and 2) after soaking in the STE at $4^{\circ}C$ immediately after soaking in distilled water at $50^{\circ}C$ for 1, 2, and 3 hr (TCM), respectively. The PE of iodine as well as the total polyphenol content improved as the temperature of the STE increased (P<0.05). The permeation of iodine was more rapid, and the total polyphenol content increased with the TCM (121 ${\mu}g/100$ mg and 1.74 mg/mL for 3 hr, respectively) compared to without the TCM (72 ${\mu}g/100$ mg and 1.48 mg/mL for 3 hr, respectively), and the highest PE was observed with the TCM after soaking at $50^{\circ}C$ for 3 hr. At a pressure of 5.0 MPa, the PE was more rapid with the TCM (139 ${\mu}g/100$ mg and 1.74 mg/mL for 90 min, respectively) than without the TCM (105 ${\mu}g/100$ mg and 1.56 mg/mL for 90 min, respectively). Consequentially, these results suggest that the preparation of seasonings and functional eggs using various components and bioactive substances is possible by the TCM.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.3
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• pp.174-183
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• 2014

Seabed beneath and near coastal structures may undergo large excess pore water pressure composed of oscillatory and residual components in the case of long durations of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. If liquefaction occurs in the seabed, the structure may sink, overturn, and eventually increase the failure potential. In this study, to evaluate the liquefaction potential on the seabed, numerical analysis was conducted using the expanded 2-dimensional numerical wave tank to account for an irregular wave field. In the condition of an irregular wave field, the dynamic wave pressure and water flow velocity acting on the seabed and the surface boundary of the composite breakwater structure were estimated. Simulation results were used as input data in a finite element computer program for elastoplastic seabed response. Simulations evaluated the time and spatial variations in excess pore water pressure, effective stress, and liquefaction potential in the seabed. Additionally, the deformation of the seabed and the displacement of the structure as a function of time were quantitatively evaluated. From the results of the analysis, the liquefaction potential at the seabed in front and rear of the composite breakwater was identified. Since the liquefied seabed particles have no resistance to force, scour potential could increase on the seabed. In addition, the strength decrease of the seabed due to the liquefaction can increase the structural motion and significantly influence the stability of the composite breakwater. Due to limitations of allowable paper length, the studied results were divided into two portions; (I) focusing on the dynamic response of structure, acceleration, deformation of seabed, and (II) focusing on the time variation in excess pore water pressure, liquefaction, effective stress path in the seabed. This paper corresponds to (II).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.3
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• pp.160-173
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• 2014

Seabed beneath and near coastal structures may undergo large excess pore water pressure composed of oscillatory and residual components in the case of long durations of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. If liquefaction occurs in the seabed, the structure may sink, overturn, and eventually increase the failure potential. In this study, to evaluate the liquefaction potential on the seabed, numerical analysis was conducted using the expanded 2-dimensional numerical wave tank to account for an irregular wave field. In the condition of an irregular wave field, the dynamic wave pressure and water flow velocity acting on the seabed and the surface boundary of the composite breakwater structure were estimated. Simulation results were used as input data in a finite element computer program for elastoplastic seabed response. Simulations evaluated the time and spatial variations in excess pore water pressure, effective stress, and liquefaction potential in the seabed. Additionally, the deformation of the seabed and the displacement of the structure as a function of time were quantitatively evaluated. From the results of the analysis, the liquefaction potential at the seabed in front and rear of the composite breakwater was identified. Since the liquefied seabed particles have no resistance to force, scour potential could increase on the seabed. In addition, the strength decrease of the seabed due to the liquefaction can increase the structural motion and significantly influence the stability of the composite breakwater. Due to limitations of allowable paper length, the studied results were divided into two portions; (I) focusing on the dynamic response of structure, acceleration, deformation of seabed, and (II) focusing on the time variation in excess pore water pressure, liquefaction, effective stress path in the seabed. This paper corresponds to (I).

• Progress in Medical Physics
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• v.11 no.2
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• pp.123-130
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• 2000

The performance of an electrometer directly affects on the accuracy and precision in radiation dosimetry. This study is to list of the quality control for maintaining performance and to perform evaluation tests of an electrometer. Performance tests selected include proper polarizing voltages, warm-up and equalization time, leakages, long-term stability, linearity, and effect of ambient conditions. An electrometer connected with a rigid stem ionization chamber was evaluated with a Strontium-90 check device. Bias voltage was measured directly on the input socket. Equalization time is the time required for reaching threshold of charged state after the power is on or the bias voltage is changed. Pre- and post-signal leakages are defined as the accumulation of signal with no exposure and after exposure, respectively. Over three months period, the electrometer's long-term stability was measured by comparison of the temperature-pressure corrected readings. Linearity was expressed as the deviation of readings from multiple short exposures from one continuous exposure. Effect of ambient conditions was expressed as the zero drift of the electrometer over 17-34$^{\circ}C$ temperature ranges. For two nominal values, 300 and 500 volts, measured voltages were lower by 2.5 and 5.8%, respectively. The warm-up time, 20 minutes, was longer than the lamp time by 9 minutes and the equalization time was less than 1 minute. Without exposure, the zero-drift was 0.002 scale-unit in 15 minutes and the leakage after 10 minutes exposure was minimal. The IQ-4 was stable over 99.4% for three-month periods. Deviation from the linearity was 0.9% for measurement scale, 0.000-9.991. Over 17-34$^{\circ}C$ temperature range, the zero-drift was minimal, less than 0.2%. For a clinically-used electrometer, a list for the basic peformance evaluations is proposed. By running this program, the measurement error using an electrometer can be reduced and in turn the improvement in accuracy and precision of radiation dosimetry can be achieved.