• The Journal of Korean Physical Therapy
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• v.21 no.4
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• pp.1-7
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• 2009

Purpose: Cervical pain is caused mainly by a static position, lasting work, bad habits and stress, and is accompanied by pain in the upper trapezius. Traditionally, heat and traction, exercise, mobilization, manipulation have been used to treat cervical pain. This study examined the effect of stretching and manipulation (high-velocity low-amplitude: HVLA) on the pain and ROM in women with chronic cervical and upper shoulder pain. Methods: Fifty-two women diagnosed with chronic cervical and upper shoulder pain were enrolled in this study. Among them, 26 patients (experiment group) were managed by passive stretching and manipulation, and another 26 patients (control group) were treated with physical therapy intervention (hat pack: HP, transcutaneous electrical nerve stimulation: TENS, ultra sound: US). Each group made use of a Visual Analogue Scale (VAS) and the highly reliable (flextion: 0.92, extention: 0.99) cervical range of motion (CROM) to compare the possible changes in pain and ROM in the two groups after treatment. Results: In the experimental group, the pain decreased and the ROM has increased in all directions. In the control group, the pain decreased but the ROM was not changed in all directions. Conclusion: According to the results, passive stretching and manipulation is effective for increasing the ROM and decreasing the level of pain. Moreover, physical therapy intervention (HP, TENS, US) is effective for immediately decreasing the pain but has little effect on the ROM.

• Journal of Korean Society on Water Environment
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• v.33 no.3
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• pp.334-340
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• 2017

A pilot-scale electrodialysis system was designed and constructed to treat groundwater polluted with arsenic and manganese. Synthetic groundwater, in which some amount of arsenic and manganese was added to make 500 mg/L of Mn and $50{\mu}g/L$ of As, was used as a feed for the ED system. The limiting current density, linear water velocity, applied voltage, and membrane surface area were investigated to obtain efficient and economic operation of the ED system. The linear water velocity was increased 0.74 cm/s to 11 cm/s based on evaluation of limiting current density. The water quality of diluate for 85 minutes of operation was satisfied with water quality criteria for drinking water using the ED system with 14 pairs of ion exchange membranes. The increased membrane pairs to 21 and 42 pairs were very effective to reduce conductivities of the diluate. The operation cost of the ED system was assessed using specific energy consumption, which was $1.065{\sim}1.2kWh/m^3$. Considering low salt concentrations of the groundwater, improvement of the ED system are required to increase current utilization and to apply low voltage while the ED system was applicable to produce drinking water.

• 한국해양학회지
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• v.13 no.1
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• pp.29-34
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• 1978

Simultaneous tidal current observation at five or seven stations on the channel near Incheon Habour was conducted at neap, mean and spring tides during the period of August 16 to August 27, 1976 and the characteristic of tidal currents with each tide was studied by the analysis of these data. Times of slack refer to the times of high and low waters at neap, mean and spring tides seem to be small. Times of maximum current refer to the times of high and low waters at the mean tide tends to appear earlier than that of the neap tide and later than that of the spring tide. The velocity ratio of maximum ebb current to maximum flood current at the mean tide has larger value than that of neap tide and has smaller value than that of spring tide. The current velocity ratio of spring tide to neap tide and to mean tide are approximately 1.8 and 1.3, respectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.5
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• pp.169-177
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• 2011

In this study, an impact resistance of concrete segmented composites adopted shell's structures which have the excellent impact resistance was assessed. In order to enhance the performances of concrete segmented composite, the bond strength of mortar between the concrete blocks should be improved. Hence, in this study polymer mortars were applied to increase the bond strength of mortar. From the results of bond tests, the 15% latex mortar was selected and static and low-velocity impact tests were carried out for the specimens applied the plain and latex mortar. The concrete segmented composites, of which the bond strength of mortar was enhanced, showed improved low-velocity impact resistances. A Nonlinear finite element analysis using the discrete crack model showed similar energy dissipating capacities to the impact test's results. Consequently, by improving the analysis models for segmented composites, the impact resistances for manifold variables can be predicted and assessed.

• Journal of the Korean Professional Engineers Association
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• v.16 no.3
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• pp.5-23
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• 1983

On the Seoul Metropolitan Subway Construction of No. 3, 4 Line, the total length is 57 Km and it is now undergoing almost 55％ progress. The working method is classified into Open Cut of 70% and the rest of 30% tunnelling method in the 48 job site. Above tunnelling method is execute by American Steel Support System and the rest of 10 job site carried out by New Austria Tunnelling Method. This paper describes Blasting Standardizations works on the above Tunnelling ' Open Cut Method under big slogan, first safety, second execution. As a superintendent, I strived standardization of works with Better powder, Better Drills ' Better Pattern. Geological structure of Seoul area is composed by Jurassic Granite and also the above rockgroup are over burden by Alluviums as a Unconformity. First of all, I carried out the standard amount of powder and burden through experimental standard blasting by each powder as following Blasting works in the subway construction is surrounding shop Building, under pass the city river and also under pass highest building basement floor. I made allowable Blasting Vibration Value by West-Germany Vornorm DIN 4150, Teil 3 and should measure each blasting works as fellows all of powder is used basically Low-Gravity and Low Velocity such as Slurry, Ammonium Nitrate ' Finex I, II. for Smooth Blasting Instead of Gelatin Dynamite. Electric Detonation Cap is used basically M/S Delay Cup instead of Electric delay ' Simultaneous cap. I applied following formula V=KW3/4 $D^{-2}$ V=Particle Velocity (Cm/sec) K=Ginh Huh's Value W=Delay Charge (Kg) D=Distance(m) In the Open Cut, within 1m distance from H-pile I made to use the Concrete breaker, as following V=7W/$^{0.5}$V/$^{-1.75}$ On the Concentrate Building area, I advise to use Light class drill ø36m Bit and advance 1.1m per round blasting the three boom jumbo drill over ø45mm used only suburb of city.e Light class drill ø36m Bit and advance 1.1m per round blasting the three boom jumbo drill over ø45mm used only suburb of city.

• Journal of the Korea Concrete Institute
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• v.23 no.1
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• pp.31-38
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• 2011

In this study, in order to observe the behaviors of fiber reinforced polymer (FRP) strengthened and steel fiber reinforced concrete specimens for impact and static loads, flexural and punching tests were performed. For the one-way flexural and two-way punching tests, concrete specimens with the dimensions of $50{\times}100{\times}350$ mm and $50{\times}350{\times}350$ mm were fabricated, respectively. The steel fiber reinforced concrete specimens showed much enhanced resistance on two-way punching of static and impact loads. In addition the FRP strengthening system provided the outstanding performance under a punching load. Because of a large tensile strength and toughness of ultra high performance concrete (UHPC), the UHPC specimens retrofitted with FRP showed marginally enhanced strength and energy dissipating capacity.

• Journal of The Korean Astronomical Society
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• v.48 no.6
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• pp.365-380
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• 2015

We map 6 massive young stellar objects (YSOs) in the CO J=2-1 line and survey 18 massive YSOs, including the six, in the HCO⁺ J=1−0, SiO J=2−1, H₂O 6₁₆ − 5₂₃ maser, and CH₃OH 7₀ − 6₁ A⁺ maser lines. We detect CO bipolar outflows in all the six mapped sources. Four of them are newly discovered (07299−1651, 21306+5540, 22308+5812, 23133+6050), while 05490+2658 is mapped in the CO J=2-1 line for the first time. The detected outflows are much more massive and energetic than outflows from low-mass YSOs with masses >20 M_⊙ and momenta >300 M_⊙ km s⁻¹. They have mass outflow rates (3−6)×10⁻⁴ M_⊙ yr⁻¹, which are at least one order of magnitude greater than those observed in low-mass YSOs. We detect HCO⁺ and SiO line emission in 18 (100%) and 4 (22%) sources, respectively. The HCO⁺ spectra show high-velocity wings in 11 (61%) sources. We detect H₂O maser emission in 13 (72%) sources and 44 GHz CH₃OH maser emission in 8 (44%) sources. Of the detected sources, 5 H₂O and 6 CH₃OH maser sources are new discoveries. 20081+3122 shows high-velocity (>30 km s⁻¹) H₂O maser lines. We find good correlations of the bolometric luminosity of the central (proto)star with the mechanical force, mechanical luminosity, and mass outflow rate of molecular outflow in the bolometric luminosity range of 10⁻¹−10⁶ L_⊙, and identified 3 intermediate- or high-mass counterparts of Class O objects.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.92-97
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• 2000

Low-velocity impact damage of a thick pressure vessel by composite materials was studied using the modified Herzian contact radius theory. Impactors of various masses and various tup shapes were dropped freely in the range of 20m to 200mm height. With acceleration gage and strain gage installed on the impactor, impact force and acceleration and Contact radius were measured. After a test, the samples were radiographed to scan the state of damage. Compared with hemispherical tup of 12.7mm diameter, the contact radius of hemispherical tup of 25.4mm diameter was bigger. And the experimental data and the theoretical data was different due to the mechanical properties difference. The acceleration value was changed linearly according to the height.

• Journal of the Korean Solar Energy Society
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• v.25 no.4
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• pp.111-118
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• 2005

The purpose of this study is to address the progress of the heat island phenomenon and the scheme to decrease in heat island phenomenon through analysis of micro-climates according to land use and make a plan to construct wind ways. The result is: 1) Analysis of temperature and humidity at 6 spots for 24 hours showed that heat island phenomenon was considerably intense around center road of Gwangju and can be mild through making lakes and green zones. 2) Analysis of the direction and velocity of the wind at 2 spots for 24 hours showed that the direction of the wind at the center of Gwangju was SSW(South-South-West) and average velocity of the it was $1.2{\sim}1.5\;m/s$. To make the inflow of the low-temperature air current from Mt. Mudeung into the city through Gwangju river, efficient management of Gwangju riverside parks should be considered for Gwangju river itself to be wind way. 3) Analysis of mobile temperature measurement on 3 courses for 24 hours showed that the low-temperature air current of Mt. Mudeung and a micro-climate of Gwangju river can lighten thermal storage phenomena of the city in that the temperature was lowest at Gwangju riverside. These outcome is from a day term measurement. So, to figure out accurate condition of heat island phenomenon in Gwangju City, it is needed to have long term measurements and accumulation of those information.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.218-225
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• 1997

This study was performed to evaluate the physical and mechanical properties of surlightweight polymer concrete using synthetic lightweight aggregate. The following conclusions were drawn; 1. Unit weight was in the range of $810~970kgf/m^3$, the unit weights of those concrete were decreased 58~65% than that of the normal cement concrete. 2. The highest strength was achieved by $P_1$, it was increased 112% by compressive strength, 378% by bending strength and 290% by tensile strength than that of the normal cement concrete, respectively. 3. Ultrasonic pulse velocity was in the range of 2,206~2,595m/s, which was low showed compared to that of the normal cement concrete. 4. Durability of surlightweight polymer concrete was superior to that of the normal cement concrete. 5. Compressive, tensile and bending strength were largely showed with the increase of unit weight. But, ultrasonic pulse velocity was low showed with the increase of unit weight.