• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.3
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• pp.223-242
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• 2024

Single-shell tunnels, introduced to South Korea in the early 2000s, have not been adopted for the main tunnels of roads or railways over the past two decades despite several attempts starting with the Gwangju City Bypass. This reluctance likely arises from concerns about the long-term performance of supporting materials and the absence of relevant criteria and specifications. However, recent progress, including the incorporation of high-strength shotcrete standards and corrosion-resistant rock bolt specifications, alongside equipment and technique enhancements, necessitates a reassessment of single-shell tunnels. While the single-shell tunnel method offers advantages in environmental impact, construction cost and period compared to the conventional NATM, it is crucial to address the challenges, such as limited design and construction experience, incomplete detailed standards, and insufficient construction specifications, through further research and pilot projects. This paper reviewed the basic principles of single-shell tunnel, current application and research status, technical development trends, criteria and specifications, and remaining challenges. It aims to reignite discussions on the feasibility of applying single-shell tunnels in South Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.9-15
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• 2016

We investigated >$50-{\mu}m$ marine planktonic organisms (mainly zooplankton) using a bongo net in Masan Bay and Jangmok Bay in order to harvest 75% of natural communities based on Phase-II approval regulations by the United States Coast Guard (USCG). The concentrated volume (in 1 ton) and abundance of zooplankton were $1.8{\times}10^7ind.ton^{-1}$ and $2.3{\times}10^7ind.ton^{-1}$, and their survival rates were 82.6% and 80.1%, respectively. The community structure in Jangmok Bay was similar to that in Masan Bay, and dominant species were adult and immature groups (stage IV) of genus Acartia. Harvested populations were inoculated in a 500-ton test tank. Although the population abundances were $6.0{\times}10^4ind.ton^{-1}$ for both bay samples, the mortality rates were higher in the Masan Bay population (32%) than the Jangmok Bay population (20%). We considered the reason to be that there were 30% more immature individuals of Acartia from Masan Bay than from Jangmok Bay. The younger population may have been greatly stressed by the moving process and netting gear. After applying a Ballast Water Treatment System (BWTS) using a sample form Jangmok Bay, the mortality rates in the treatment groups were found to be 100% after 0 days and 5 days, implying that the BWTS worked well. During the winter season, the zooplankton concentration method alone did not easily satisfy the approval standards of USCG Phase II (> $10{\times}10^4ind.ton^{-1}$ in the 500 ton tank). Increasing the netting frequency and additional fishing boats may be helpful in meeting the USCG Phase II biological criteria.

• The Journal of the Korea Contents Association
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• v.6 no.4
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• pp.146-157
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• 2006

Causal relationship means what relations the result occurred have with a fact as a reason. In general, a formular that no result exists without reasons is used for the method to confirm existence and inexistence of causal relationship. Problematic causal relationships in Private Law are reparations (Article No. 393 of Private Law) due to debt nonfulfillment and reparation due to tort (Application of Article No. 393 by Article No. 750, and No. 763 of Private Law). The purpose pursued by reparation system in private law is to promote equal burden of damages, and the range of reparation at this time is decided by the range of damage and the range of damage is decided by the principle of causal relationship. That the causal relationship theory fairly causes confusion by treating one problem and the other problem as the same thing, instead of dividing them according to the purpose of protection presented by the law is a reason of the criticism from different views.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.149-155
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• 2012

Purpose : Serum insulin levels are useful indicator which of reflecting the function of insulin secretion in pancreatic ${\beta}$ cell and diagnosis of diabetes, differentiating the cause of impaired glucose tolerance. Insulin measurement kits have shown some differences in many ways such as test methods as well as quality control. The purpose of this study was to evaluate the diagnostic performance of seven manufacturing companies commercial kits. Materials and Methods : The values of insulin measured by three manufacturing companies (Biosource, Siemens, TFB) with 59 samples in August 2009 were compared with those measured by four manufacturing companies (Immunotech, Izotope, BNIBT, Cisbio) with 68 samples in December 2011. We evaluated precision, recovery rate, dilution test and correlation of serum insulin measurement using seven manufacturing company kits. Statistical program SPSS 12.0 was used for the verification of results. Results : The coefficients variation of the precision on all seven different kits were showed within 5.0%. Recovery rate of Biosource, Siemens, TFB kits on three different levels showed 94.2~103.7%, 99.0~104.6%, 99.7~107.6% respectively. Immunotech, Izotope, BNIBT, Cisbio were 93.5~99.1%, 91.4~99.1%, 99.2~131.0%, 84.8~102.3% respectively. There was strong correlation between the measurement of insulin by Biosource kit and that by two commercial kits, Siemens (R2=0.96), TFB (R2=0.99). There was good correlation between the measurement of insulin by TFB kit and that by three commercial kits, Immunotech (R2=0.97), Izotope (R2=0.96), Cisbio (R2=0.97). In the dilution test performed with more than 200 ${\mu}IU/ml$ high concentration samples, samples with diabetes correctly was measured in all seven manufacturing kits. However, as measured with insulinoma samples TFB, Siemens, Izotope, Cisbio kits were correctly measured, but Biosource and Immunotech kits were measured 47.4 ${\mu}IU/ml$, 72.3 ${\mu}IU/ml$, respectively. Conclusion : Serum Insulin radioimmunoassay kits were showed excellent precision, correlation and good recovery rate. However, some kits were not measured correctly in the high concentration insulin values. when selecting a kit should be considered many factors that cost effectiveness, compatible for automation equipment, high performance kit, the environment for each laboratory such as reaction time and reporting time.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.289-293
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• 2005

Nowadays there are many sun protection cosmetics including organic or inorganic UV filter as an active ingredient. Chemically stable inorganic sunsEreen agents, usually metal oxides, we widely employed in high SPF products. Titanium dioxide is one of the most frequently used inorganic UV filters. It has been used as pigments for a long period of cosmetic history. With the development of micronization techniques, it becomes possible to incorporate titanium dioxide in sunscreen formulations without whitening effect and it becomes an important research topic. However, there are very few works related to quantitations of titanium dioxide in sunscreen products. In this research, we analyzed amounts of titanium dioxide in sunscreen cosmetics by adapting redof titration, reduction of Ti(IV) to Ti(III) and reoxidation to Ti(IV). After calcification of other organic ingredients of cosmetics, titanium dioxide is dissolved by hot sulfuric acid. The dissolved Ti(IV) is reduced to the Ti(III) by adding aluminum metals. The reduced Ti(III) is titrated against a standard oxidizing agent, Fe(III) (ammonium iron(III) sulfate), with potassium thiocyanate as an indicator In order to test accuracy and applicability of the proposed method, we analyzed the amounts of titanium dioxide in four types of sunscreen cosmetics, such as cream, make-up base, foundation and powder, after adding known amounts of titanium dioxide $(1{\sim}25w/w%)$. The percent recoveries of the titanium dioxide in four types of formulations were in the range between 96 and 105%. We also analyzed 7 commercial cosmetic products labeled titanium dioxide as an ingredient and compared the results with those of obtained from ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry), one of the most powerful atomic analysis techniques. The results showed that the titrated amounts were well coincided with the analyzed amounts of titanium dioxide by ICP-AES. Although instrumental analytical methods, ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) and ICP-AES, are the best for the analysis of titanium, it is hard to adopt because of their high prices for small cosmetic companies. It was found that the volumetric method presented here gat e quantitative and reliable results with routine lab-wares and chemicals.

• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.1
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• pp.34-40
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• 2021

Purpose If a new test is introduced or reagents are changed in the laboratory of a medical institution, the characteristics of the test should be analyzed according to the procedure and the assessment of reagents should be made. However, several necessary conditions must be met to perform all required comparative evaluations, first enough samples should be prepared for each test, and secondly, various reagents applicable to the comparative evaluations must be supplied. Even if enough comparative evaluations have been done, there is a limit to the fact that the data variation for the new reagent represents the overall patient data variation, The fact puts a burden on the laboratory to the change the reagent. Due to these various difficulties, reagent changes in the laboratory are limited. In order to introduce a competitive bid, the institute conducted a full investigation of Radioimmunoassay(RIA) reagents for each test and established the range of reagents available in the laboratory through comparative evaluations. We wanted to share this process. Materials and Methods There are 20 items of tests conducted in our laboratory except for consignment tests. For each test, RIA reagents that can be used were fully investigated with the reference to external quality control report. and the manuals for each reagent were obtained. Each reagent was checked for the manual to check the test method, Incubation time, sample volume needed for the test. After that, the primary selection was made according to whether it was available in this laboratory. The primary selected reagents were supplied with 2kits based on 100tests, and the data correlation test, sensitivity measurement, recovery rate measurement, and dilution test were conducted. The secondary selection was performed according to the results of the comparative evaluation. The reagents that passed the primary and secondary selections were submitted to the competitive bidding list. In the case of reagent is designated as a singular, we submitted a explanatory statement with the data obtained during the primary and secondary selection processes. Results Excluded from the primary selection was the case where TAT was expected to be delayed at the moment, and it was impossible to apply to our equipment due to the large volume of reagents used during the test. In the primary selection, there were five items which only one reagent was available.(squamous cell carcinoma Ag(SCC Ag), β-human chorionic gonadotropin(β-HCG), vitamin B12, folate, free testosterone), two reagents were available(CA19-9, CA125, CA72-4, ferritin, thyroglobulin antibody(TG Ab), microsomal antibody(Mic Ab), thyroid stimulating hormone-receptor-antibody(TSH-R-Ab), calcitonin), three reagents were available (triiodothyronine(T3), Tree T3, Free T4, TSH, intact parathyroid hormone(intact PTH)) and four reagents were available are carcinoembryonic antigen(CEA), TG. In the secondary selection, there were eight items which only one reagent was available.(ferritin, TG, CA19-9, SCC, β-HCG, vitaminB12, folate, free testosterone), two reagents were available(TG Ab, Mic Ab, TSH-R-Ab, CA125, CA72-4, intact PTH, calcitonin), three reagents were available(T3, Tree T3, Free T4, TSH, CEA). Reasons excluded from the secondary selection were the lack of reagent supply for comparative evaluations, the problems with data reproducibility, and the inability to accept data variations. The most problematic part of comparative evaluations was sample collection. It didn't matter if the number of samples requested was large and the capacity needed for the test was small. It was difficult to collect various concentration samples in the case of a small number of tests(100 cases per month or less), and it was difficult to conduct a recovery rate test in the case of a relatively large volume of samples required for a single test(more than 100 uL). In addition, the lack of dilution solution or standard zero material for sensitivity measurement or dilution tests was one of the problems. Conclusion Comparative evaluation for changing test reagents require appropriate preparation time to collect diverse and sufficient samples. In addition, setting the total sample volume and reagent volume range required for comparative evaluations, depending on the sample volume and reagent volume required for one test, will reduce the burden of sample collection and planning for each comparative evaluation.

• Sijohaknonchong
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• v.23
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• pp.161-188
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• 2005

The purpose of this study was to delve into the morphological types of Sijo in an effort to determine the morphological structure of Sasul-sijo, and it's also attempted to present standard about how to discriminate Pyong-si, Eos-sijo and Sasul-sijo from one another from a morphological standpoint. It's suggested that Si with tee Jangs, six verses and 12 stanzas or more, with three Jangs, seven verses and 14 stanzas or more, and with three Jangs, eight verses and 16 stanzas or more should respectively be called Pyong-sijo, Eos-sijo and Sasul-sijo. After what Sijo was and what's not were discussed, how to distinguish Eos-sijo from Sasul-sijo was described, and finally, the structure of Sasul-sijo was presented. As for Sijo and non-Sijo, the types of works that consisted of tee Jangs, like Sijo, yet didn't suit its framework and Yuljo and were written in Chinese characters were regarded as non-Sijo. Concerning discrimination between Eos-si and Sasul-sijo, the type of Sijo that included one more or higher number of verse(s) and two more or higher number of stanzas in one of three Jangs was defined as Eos-sijo, and the type of Sijo that involved two more or higher number of verses and four more or higher number of stanzas in one of three Jangs was called Sasul-sijo. In other words, Eos-sijo contained one more verse in one of tee Jangs, and Sasul-sijo included one more Jang in one tee Jangs. The sort of Sijo that contained one more Jang in one of three Jangs could be viewed as Sasul-sijo. Regarding the structure of Sasul-si, there should be three Jangs, eight verses and 16 stanzas in one piece of Sasul-sijo. Any type of Sijo that contained two more or higher number of verses and four more or higher number of stanzas could be called Sasul-sijo. Such an addition of verse and stanza could done in various ways. The examples were (1) adding stanzas the first Jang, 2) adding stanzas to the second Jang, (3) adding stanzas to the final Jang, (4) adding stanzas to both the first and Second Jangs, (5) adding stanzas to th the second and final Jangs, and (6) adding stanzas to all the first, second and third Jangs at the same time. Besides, there was an extremely broad gap between the numbers of verse and stanza in Sasul-sijo, which ranged from a low of eight stanzas to a high of 87 ones in one of three Jangs.

• Analytical Science and Technology
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• v.28 no.6
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• pp.409-416
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• 2015

ICP-AES has been used in many laboratories due to the advantages of wide calibration range and multi-element analysis, but it may give erroneous results and suffer from spectral interference due to the large number of emission lines associated with each element. In this study, certified reference materials (CRMs) and field samples were analyzed by ICP-AES and HG-AAS according to the official Korean testing method for soil pollution to investigate analytical problems. The applicability of HG-ICP-AES was also tested as an alternative method. HG-AAS showed good accuracies (90.8~106.3%) in all CRMs, while ICP-AES deviated from the desired range in CRMs with low arsenic and high Fe/Al. The accuracy in CRM030 was estimated as below 39% at the wavelength of 193.696 nm by ICP-AES. Significant partial overlaps and sloping background interferences were observed near to 193.696 nm with the presence of 50 mg/L Fe and Al. Most CRMs were quantified with few or no interferences of Fe and Al at 188.980 nm. ICP-AES properly assessed low and high level arsenic for field samples, at 188.980 nm and 193.696 nm, respectively. The importance of the choice of measurement wavelengths corresponding to relative arsenic level should be noted. Because interferences were affected by the sample matrix, operation conditions and instrument figures, the analysts were required to consider spectral interferences and compare the analytical performance of the recommended wavelengths. HG-ICP-AES was evaluated as a suitable alternative method for ICP-AES due to improvement of the detection limit, wide calibration ranges, and reduced spectral interferences by HG.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.1
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• pp.48-57
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• 2015

In a sodium-cooled fast reactor, which is a Generation-IV reactor, refueling is conducted by rotating, but not opening, the reactor head to prevent a reaction between the sodium, water and air. Therefore, an inspection technique that checks for the presence of any obstacles between the reactor core and the upper internal structure, which could disturb the rotation of the reactor head, is essential prior to the refueling of a sodium-cooled fast reactor. To this end, an ultrasound-based inspection technique should be employed because the opacity of the sodium prevents conventional optical inspection techniques from being applied to the monitoring of obstacles. In this study, a ranging inspection technique using a plate-type ultrasonic waveguide sensor was developed to monitor the presence of any obstacles between the reactor core and the upper internal structure in the opaque sodium. Because the waveguide sensor installs an ultrasonic transducer in a relatively cold region and transmits the ultrasonic waves into the hot radioactive liquid sodium through a long waveguide, it offers better reliability and is less susceptible to thermal or radiation damage. A 10 m horizontal beam waveguide sensor capable of radiating an ultrasonic wave horizontally was developed, and beam profile measurements and basic experiments were carried out to investigate the characteristics of the developed sensor. The beam width and propagation distance of the ultrasonic wave radiated from the sensor were assessed based on the experimental results. Finally, a feasibility test using cylindrical targets (corresponding to the shape of possible obstacles) was also conducted to evaluate the applicability of the developed ranging inspection technique to actual applications.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.1
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• pp.2162-2176
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• 1971

From the ancient times our forefathers settled down in this peninsular and cultivated the hills and waste-lands into fields. Instead of fertilizing the lands they moved to find other fertile lands and lived a feudal life of agriculture and various machines played a main role in the land reclamation. The best method of land clearing, the time and efficiency in the operation and the effect of growing crops should sysematically analized prior to the time of 3rd Five-year Economic Development(1972-1976) in order to cultivated 210,000 ha of waste-land or the modernization of our country. The present study was investigated to find out a new working-system of mechanical land clearing and development of fertile soil. The results are as follows: 1) The land reclamation in natural slope is much more encourageable in land clearing and farming when the slope is below ten grades than bench terrace. 2) Weeds were mixed with soil in the land clearing work in order to supply organic materials and to make soil swollen instead of burning of just removing. 3) The equipments such as bulldozers, harrows, power tillers and so on should be prepared in order to do a systematic work in the land clearing. 4) The work of pulling-up roots is dependent upon the forms of roots spreading under the ground. The work of the pulling-up the straight roots was most difficult. 5) The land clearing work of the wrinkled style blocks was easy in pulling up roots and in the time of first plowing. The harrowing work could also be simply done. 6) The amount of soil carried was $240m^3/10a$, 15.6% increased amount from the standard block, while the required time of clearing work was 2 hours 15 minutes 45 seconds/10a, the one third of time required for the standard block. 7) The time disc harrowing work increased 50%, or 15 minutes/10a compared to the harrowing work required in the cultivated soil. 8) The time of rotary tilling increased 2.4 times or 1 hour 47 minutes 43 seconds/10a compared to the time required in the cultivated soil. 9) The reclamed land should be fertilized according to the soil quality, especially added fertilizer should be more than 1,200kg/10a, limes 20kg/10a. In order to produce added fertilizer grass fields should be needed. 10) The experiment of pasture growing is now progressing and therefore the effect of land clearing and the degree of developed soil will be investigated before long.